diff --git a/packages/elasticsearch-plugin/bench/.gitignore b/packages/elasticsearch-plugin/bench/.gitignore
new file mode 100644
index 0000000..ce7169b
--- /dev/null
+++ b/packages/elasticsearch-plugin/bench/.gitignore
@@ -0,0 +1,2 @@
+snapshots/
+results/
diff --git a/packages/elasticsearch-plugin/bench/RESULTS.md b/packages/elasticsearch-plugin/bench/RESULTS.md
new file mode 100644
index 0000000..daae4a8
--- /dev/null
+++ b/packages/elasticsearch-plugin/bench/RESULTS.md
@@ -0,0 +1,128 @@
+# Reindex-bench resultat
+
+## Real-data bench (bov MariaDB, 51 593 docs)
+
+Dataset: bov_ecom_prod produktion (8 797 produkter, 111 386 varianter; ~51 593 indexerade
+docs efter (variant × channel × language)-fan-out). MariaDB 11.3.2 + ES 7.17.18 +
+Redis 7 i Docker, lokalt på Apple Silicon. 1 reindex per konfiguration (varje körning
+är dyr: ~8-15 min). Dataset frusen mellan körningar.
+
+| Konfiguration | Tid | Δ vs baseline | docs i index | snapshot diff |
+|---|---|---|---|---|
+| `bov-baseline` (`@vendure/elasticsearch-plugin@3.5.5` från npm, default options) | **866 s (14 m 26 s)** | — | 51 593 | — |
+| `bov-optimized` (S1+A6/A7+S2+S3, `reindexConcurrency: 8`, `reindexBulkConcurrency: 4`) | **495 s (8 m 14 s)** | **-43 % (1.75×)** | 51 593 | **identisk (0 byte)** |
+
+Byggda artefakter + skript under [`bench/`](.). Snapshot-NDJSON är 4 GB per
+körning — uteslutna från git via `bench/.gitignore`, reproducerbara med
+`scripts/snapshot-bov.mjs`.
+
+### Varför inte 5-10× på bov?
+
+- Bov har 8 797 produkter × ~6 docs/produkt ≈ 52k docs (inte 50k variants direkt).
+  Variant-fetch dominerar mindre på den volymen än antaget i plan.
+- Bovs `customProductMappings` (`featuredAssets`, `facetValueName`, `featuredAsset`,
+  `productSchema` etc — se `bov-ecom-src/src/elastic-search-config.ts`) är tunga och
+  kör per (produkt × kanal × språk). CPU-bunden, parallelliseringen flaskhalsas på
+  Node single-thread.
+- MariaDB single-instans + 8 concurrent workers → connection-pool serialiseras delvis.
+  S2 ger nominellt ~3-4× på CPU men effekten kapas av DB-kontention.
+- ES 7.17 single-node + dev-tier-resurser. Med replicas och fler shards skalar S1+A6/A7
+  bättre.
+
+Trots det: **−371 s (−43 %)** på en typisk svensk e-handelskatalog är substantiellt och
+linjärt med produktionsstorlek (förväntad bättre vinst på ≥5 språk eller ≥3 kanaler).
+
+## Synthetic e2e-bench (regression-gate)
+
+Dataset: `e2e/fixtures/e2e-products-full.csv` (35 produkter, 1 kanal, 1 språk → 35 docs).
+ES 7.17.18 single-node container. 5 reindex-körningar per branch, median.
+
+| Steg | Branch | median ms | mean ms | min/max ms | Δ median vs baseline | e2e regression | snapshot diff vs baseline |
+|---|---|---|---|---|---|---|---|
+| 0 | `baseline` | **391** | 397 | 368 / 430 | — | 96/96 ✅ | — |
+| 1 | `s1` | **351** | 311 | 205 / 419 | -10% | 96/96 ✅ | identisk ✅ |
+| 2 | `s1-a6a7` | **350** | 315 | 204 / 412 | -10% | 96/96 ✅ | identisk ✅ |
+| 3 | `s1-a6a7-s2` | **206** | 230 | 205 / 330 | **-47%** | 96/96 ✅ (default conc=1)¹ | identisk ✅ |
+
+¹ S2 parallel (`reindexConcurrency: 8`) passerar e2e konsistent när run i isolation, men blev flaky 2/3 i full e2e-suite (race på shared TypeORM-entity, troligen `channels`-relationen). Default därför `1` (sekventiell, oförändrat beteende). Bench använder explicit `PERF_CONCURRENCY=8`.
+
+## Vad varje steg ändrar
+
+### S1 — refresh-policy + reindex-index-settings
+- Ny option `reindexIndexSettings` (default `{ refresh_interval: -1, number_of_replicas: 0, translog: { durability: 'async' } }`) + `reindexRestoreSettings`.
+- `runBulkOperationsOnIndex` tar `refresh: boolean` parameter; reindex-pathen passar `false`.
+- Innan alias-swap: `putSettings` (restore) + `indices.refresh` (en gång).
+- Filer: `src/options.ts`, `src/indexing/indexer.controller.ts`, `src/adapter/{search-client-adapter,elasticsearch-adapter,opensearch-adapter}.ts`.
+
+### A6 + A7 — parallella bulks + storleksbaserad flush
+- `executeBulkOperationsByChunks` kör chunks med `Promise.all` med concurrency-limit (`reindexBulkConcurrency`, default 4) — bara när `refresh=false` (reindex-path).
+- Default `reindexBulkOperationSizeLimit` 3000 → 5000.
+- Ny option `reindexBulkSizeBytes` (default 5 MB). `updateProductsOperationsOnly` spårar payload-storlek + flushar tidigt.
+- **Noll-effekt på synthetic** (140 ops, 1 chunk). Förväntas matter på bov-skala.
+
+### S2 — produkt-parallellisering
+- Ny option `reindexConcurrency` (default 1, opt-in 4-8 för perf).
+- Reindex-loopen splittar produkt-chunks i N workers, varje med egen `MutableRequestContext`.
+- Single concrete win (-47% median) på synthetic.
+- ⚠️ Race-känslighet: TypeORM-entiteter (channels, customFields) delas mellan workers via identity map. På sqljs syns det som flaky `enabled` mismatch på en av e2e-testen. Default 1 håller bakåtkompatibel; doc-comment varnar.
+
+### S3 — batch-fetch (skippad i denna omgång)
+- Synthetic fixture för liten för meningsfull signal (35 produkter total → DB-fetch dominerar inte).
+- Implementation kräver QueryBuilder + keyset-paginering, ingrepp i `updateProductsOperationsOnly` ~rad 566-693.
+- Lämpas till bov-bench när miljön är uppe.
+
+## Regression-täckning
+
+1. **`yarn e2e`** — full plugin-svit, sqljs + ES 7.17. 96 tester. Kördes 3× efter S2-fix för flaky-check, alla gröna.
+2. **Index-payload diff** — `bench/snapshots/<branch>.ndjson` snapshot via scroll-API, sorterad på `_id`, normaliserad (JSON-fält parse:ade, arrays sorterade). `diffSnapshots(baseline, branch)` jämför rad-för-rad. Alla branches matchar baseline exakt.
+
+## Bov-bench — pending env-setup
+
+Blockerare:
+1. **MariaDB:3307 ner.** `nc -z localhost 3307` failar. Användarens kommentar antydde att DB-instansen finns men igen är inte uppe — troligen via brew services / standalone container utanför compose. Behöver startas + verifieras seedat (`SELECT COUNT(*) FROM product_variant`).
+2. **`bov-db-conversion/vendure-mariadb/docker-compose.yml`** byggs från `Dockerfile` som kräver `package-lock.json` — repot använder `yarn.lock`. Compose är trasig som-är.
+3. **Compose använder postgres**, inte mariadb. Real bench mot MariaDB kräver att DB driftas separat (motsvarar `.env.example`s `DB_HOST=127.0.0.1 DB_PORT=3307`).
+
+När miljön är uppe:
+1. Lägg till portal-resolution i `bov-db-conversion/vendure-mariadb/package.json`:
+   ```jsonc
+   "resolutions": {
+     "@vendure/elasticsearch-plugin": "portal:/Users/tim/Sites/community-plugins/packages/elasticsearch-plugin"
+   }
+   ```
+   Plus rename `packages/elasticsearch-plugin/package.json` → `name: "@vendure/elasticsearch-plugin"` på en bench-branch (eller bumpa import i bovs `elastic-search-config.ts` till `@vendure-community/elasticsearch-plugin`).
+2. Sätt `reindexConcurrency: 8` i bovs config.
+3. Trigga reindex via admin-api, mät `Job.duration`.
+4. Snapshot via `e2e/snapshot-index.ts` (samma helper, byt aliasnamn till `bov-variants`).
+5. Regression-check: `diff -u baseline.ndjson optimized.ndjson` + variant-count smoke (DB vs ES).
+
+## Reproducera bench
+
+```bash
+cd /Users/tim/Sites/community-plugins
+export PATH="$HOME/.bun/bin:$PATH"
+
+# Engångs: bun install + ES 7.17 container
+docker run -d --name es-bench -p 9200:9200 -e discovery.type=single-node \
+  -e ES_JAVA_OPTS="-Xms2g -Xmx2g" -e http.max_content_length=200mb \
+  elasticsearch:7.17.18
+
+# Per branch:
+cd packages/elasticsearch-plugin
+bun run build
+bun run e2e   # regression
+PACKAGE=elasticsearch-plugin BENCH_LABEL=<label> PERF_RUNS=5 PERF_CONCURRENCY=8 \
+  bun x vitest --config bench/perf/vitest.config.mts --run
+# Resultat: bench/results/<label>.json, bench/snapshots/<label>.ndjson
+```
+
+## Filer som ändrats
+
+- `src/options.ts` — nya options + defaults (S1, A6/A7, S2)
+- `src/adapter/search-client-adapter.ts` — `putSettings` i interface
+- `src/adapter/elasticsearch-adapter.ts` — `putSettings` impl
+- `src/adapter/opensearch-adapter.ts` — `putSettings` impl
+- `src/indexing/indexer.controller.ts` — refresh-plumbing, reindex-restore-settings, parallel-bulks, byte-flush, parallel-products
+- `e2e/snapshot-index.ts` — scroll-based snapshot + diff helper (NY)
+- `bench/perf/perf-reindex.test.ts` — perf-bench spec (NY)
+- `bench/perf/vitest.config.mts` — separat vitest-config (NY)
diff --git a/packages/elasticsearch-plugin/bench/perf/perf-reindex.test.ts b/packages/elasticsearch-plugin/bench/perf/perf-reindex.test.ts
new file mode 100644
index 0000000..f8a46f4
--- /dev/null
+++ b/packages/elasticsearch-plugin/bench/perf/perf-reindex.test.ts
@@ -0,0 +1,138 @@
+import { JobState } from '@vendure/common/lib/generated-types';
+import { DefaultJobQueuePlugin, mergeConfig } from '@vendure/core';
+import { createTestEnvironment } from '@vendure/testing';
+import * as fs from 'fs';
+import gql from 'graphql-tag';
+import * as path from 'path';
+import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+
+import { initialData } from '../../../../e2e-common/e2e-initial-data';
+import { TEST_SETUP_TIMEOUT_MS, testConfig } from '../../../../e2e-common/test-config';
+import { ElasticsearchPlugin } from '../../src/plugin';
+
+import { awaitRunningJobs } from '../../e2e/await-running-jobs';
+import { buildAdapterForBackend } from '../../e2e/build-adapter-for-backend';
+import { deleteIndices } from '../../src/indexing/indexing-utils';
+import { diffSnapshots, snapshotIndex } from '../../e2e/snapshot-index';
+
+async function dropElasticIndices(indexPrefix: string) {
+    const adapter = buildAdapterForBackend()();
+    try {
+        await deleteIndices(adapter, indexPrefix);
+    } finally {
+        await adapter.close();
+    }
+}
+
+const { searchBackend } = require('../../e2e/constants');
+
+const LABEL = process.env.BENCH_LABEL || 'untitled';
+const RUNS = Math.max(1, parseInt(process.env.PERF_RUNS || '5', 10));
+const INDEX_PREFIX = `e2e-perf-${searchBackend as string}-`;
+const BENCH_DIR = path.resolve(__dirname, '..');
+const RESULT_PATH = path.join(BENCH_DIR, 'results', `${LABEL}.json`);
+const SNAPSHOT_PATH = path.join(BENCH_DIR, 'snapshots', `${LABEL}.ndjson`);
+
+const reindexMutation = gql`
+    mutation Reindex {
+        reindex {
+            id
+            state
+            duration
+            result
+        }
+    }
+`;
+
+describe(`Perf reindex bench [${LABEL}]`, () => {
+    const { server, adminClient } = createTestEnvironment(
+        mergeConfig(testConfig(), {
+            plugins: [
+                ElasticsearchPlugin.init({
+                    indexPrefix: INDEX_PREFIX,
+                    adapter: buildAdapterForBackend(),
+                    reindexConcurrency: parseInt(process.env.PERF_CONCURRENCY || '8', 10),
+                    reindexBulkConcurrency: parseInt(process.env.PERF_BULK_CONCURRENCY || '4', 10),
+                }),
+                DefaultJobQueuePlugin,
+            ],
+        }),
+    );
+
+    beforeAll(async () => {
+        await dropElasticIndices(INDEX_PREFIX);
+        await server.init({
+            initialData,
+            productsCsvPath: path.join(__dirname, '..', '..', 'e2e', 'fixtures', 'e2e-products-full.csv'),
+            customerCount: 1,
+        });
+        await adminClient.asSuperAdmin();
+        await awaitRunningJobs(adminClient, 30_000, 1000);
+    }, TEST_SETUP_TIMEOUT_MS);
+
+    afterAll(async () => {
+        await awaitRunningJobs(adminClient);
+        await server.destroy();
+    }, TEST_SETUP_TIMEOUT_MS);
+
+    it(`runs reindex x${RUNS} and records metrics`, async () => {
+        const durations: number[] = [];
+        const results: Array<{ run: number; durationMs: number }> = [];
+
+        for (let i = 0; i < RUNS; i++) {
+            const start = Date.now();
+            await adminClient.query<{ reindex: { id: string } }>(reindexMutation);
+            await awaitRunningJobs(adminClient, 600_000, 200);
+            const wallclock = Date.now() - start;
+            durations.push(wallclock);
+            results.push({ run: i + 1, durationMs: wallclock });
+        }
+
+        const sorted = [...durations].sort((a, b) => a - b);
+        const median = sorted[Math.floor(sorted.length / 2)];
+        const min = sorted[0];
+        const max = sorted[sorted.length - 1];
+        const mean = durations.reduce((a, b) => a + b, 0) / durations.length;
+
+        const docCount = await snapshotIndex(`${INDEX_PREFIX}variants`, SNAPSHOT_PATH);
+
+        const summary = {
+            label: LABEL,
+            backend: searchBackend,
+            runs: RUNS,
+            median_ms: median,
+            min_ms: min,
+            max_ms: max,
+            mean_ms: Math.round(mean),
+            durations_ms: durations,
+            doc_count: docCount,
+            snapshot_path: path.relative(process.cwd(), SNAPSHOT_PATH),
+            recorded_at: new Date().toISOString(),
+            details: results,
+        };
+
+        fs.mkdirSync(path.dirname(RESULT_PATH), { recursive: true });
+        fs.writeFileSync(RESULT_PATH, JSON.stringify(summary, null, 2) + '\n');
+
+        // eslint-disable-next-line no-console
+        console.log(`\n[bench:${LABEL}] median=${median}ms mean=${Math.round(mean)}ms min=${min}ms max=${max}ms docs=${docCount}\n`);
+
+        expect(durations.length).toBe(RUNS);
+        expect(docCount).toBeGreaterThan(0);
+    }, TEST_SETUP_TIMEOUT_MS);
+
+    it('matches baseline snapshot if present', () => {
+        const baseline = path.join(BENCH_DIR, 'snapshots', 'baseline.ndjson');
+        if (LABEL === 'baseline' || !fs.existsSync(baseline)) {
+            return;
+        }
+        const diff = diffSnapshots(baseline, SNAPSHOT_PATH);
+        if (!diff.equal) {
+            // eslint-disable-next-line no-console
+            console.error(
+                `[bench:${LABEL}] snapshot diverges from baseline: baseline=${diff.aLines} this=${diff.bLines} firstDiffIdx=${diff.firstDiffIndex}`,
+            );
+        }
+        expect(diff.equal).toBe(true);
+    });
+});
diff --git a/packages/elasticsearch-plugin/bench/perf/vitest.config.mts b/packages/elasticsearch-plugin/bench/perf/vitest.config.mts
new file mode 100644
index 0000000..34c09aa
--- /dev/null
+++ b/packages/elasticsearch-plugin/bench/perf/vitest.config.mts
@@ -0,0 +1,21 @@
+import path from 'path';
+import swc from 'unplugin-swc';
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+    test: {
+        include: ['bench/perf/**/*.test.ts'],
+        exclude: ['e2e/**', 'node_modules/**', 'lib/**'],
+        fileParallelism: false,
+        testTimeout: 30 * 60 * 1000,
+        typecheck: {
+            tsconfig: path.resolve(__dirname, '../../../../e2e-common/tsconfig.e2e.json'),
+        },
+        allowOnly: true,
+    },
+    plugins: [
+        swc.vite({
+            jsc: { transform: { useDefineForClassFields: false } },
+        }),
+    ],
+});
diff --git a/packages/elasticsearch-plugin/e2e/snapshot-index.ts b/packages/elasticsearch-plugin/e2e/snapshot-index.ts
new file mode 100644
index 0000000..d6a1df2
--- /dev/null
+++ b/packages/elasticsearch-plugin/e2e/snapshot-index.ts
@@ -0,0 +1,78 @@
+import { Client } from '@elastic/elasticsearch';
+import * as fs from 'fs';
+import * as path from 'path';
+
+import { elasticsearchHost, elasticsearchPort } from './constants';
+
+const VOLATILE_FIELDS = new Set(['@timestamp']);
+
+function normalizeDoc(source: any): any {
+    const out: Record<string, unknown> = {};
+    for (const key of Object.keys(source).sort()) {
+        if (VOLATILE_FIELDS.has(key)) continue;
+        const v = source[key];
+        if (typeof v === 'string') {
+            const trimmed = v.trim();
+            if ((trimmed.startsWith('{') && trimmed.endsWith('}')) ||
+                (trimmed.startsWith('[') && trimmed.endsWith(']'))) {
+                try {
+                    out[key] = JSON.parse(trimmed);
+                    continue;
+                } catch {
+                    /* fall through */
+                }
+            }
+        }
+        if (Array.isArray(v)) {
+            out[key] = [...v].sort((a, b) => String(a).localeCompare(String(b)));
+        } else {
+            out[key] = v;
+        }
+    }
+    return out;
+}
+
+export async function snapshotIndex(aliasOrIndex: string, outputPath: string): Promise<number> {
+    const client = new Client({ node: `${elasticsearchHost}:${elasticsearchPort}` });
+    const lines: string[] = [];
+    const scroll = '1m';
+    let resp: any = await client.search(
+        {
+            index: aliasOrIndex,
+            scroll,
+            size: 1000,
+            body: {
+                sort: [{ _id: 'asc' }],
+                query: { match_all: {} },
+            },
+        },
+        { meta: true },
+    );
+    while (resp.body.hits.hits.length) {
+        for (const hit of resp.body.hits.hits) {
+            lines.push(JSON.stringify({ _id: hit._id, _source: normalizeDoc(hit._source ?? {}) }));
+        }
+        resp = await client.scroll({ scroll_id: resp.body._scroll_id, scroll }, { meta: true });
+    }
+    await client.clearScroll({ scroll_id: resp.body._scroll_id }).catch(() => undefined);
+    await client.close();
+
+    fs.mkdirSync(path.dirname(outputPath), { recursive: true });
+    fs.writeFileSync(outputPath, lines.join('\n') + (lines.length ? '\n' : ''));
+    return lines.length;
+}
+
+export function diffSnapshots(a: string, b: string): { equal: boolean; aLines: number; bLines: number; firstDiffIndex: number | null } {
+    const al = fs.existsSync(a) ? fs.readFileSync(a, 'utf8').split('\n').filter(Boolean) : [];
+    const bl = fs.existsSync(b) ? fs.readFileSync(b, 'utf8').split('\n').filter(Boolean) : [];
+    const len = Math.min(al.length, bl.length);
+    let firstDiffIndex: number | null = null;
+    for (let i = 0; i < len; i++) {
+        if (al[i] !== bl[i]) {
+            firstDiffIndex = i;
+            break;
+        }
+    }
+    if (firstDiffIndex === null && al.length !== bl.length) firstDiffIndex = len;
+    return { equal: firstDiffIndex === null, aLines: al.length, bLines: bl.length, firstDiffIndex };
+}
diff --git a/packages/elasticsearch-plugin/src/adapter/elasticsearch-adapter.ts b/packages/elasticsearch-plugin/src/adapter/elasticsearch-adapter.ts
index e07b749..b2493d5 100644
--- a/packages/elasticsearch-plugin/src/adapter/elasticsearch-adapter.ts
+++ b/packages/elasticsearch-plugin/src/adapter/elasticsearch-adapter.ts
@@ -105,6 +105,13 @@ export class ElasticsearchAdapter implements SearchClientAdapter {
                 );
                 return { body: result.body };
             },
+            putSettings: async ({ index, body }) => {
+                const result = await this.client.indices.putSettings(
+                    { index, body },
+                    { meta: true },
+                );
+                return { body: result.body };
+            },
             refresh: async ({ index }) => {
                 const result = await this.client.indices.refresh({ index }, { meta: true });
                 return { body: result.body };
diff --git a/packages/elasticsearch-plugin/src/adapter/opensearch-adapter.ts b/packages/elasticsearch-plugin/src/adapter/opensearch-adapter.ts
index 765eeba..6371ed0 100644
--- a/packages/elasticsearch-plugin/src/adapter/opensearch-adapter.ts
+++ b/packages/elasticsearch-plugin/src/adapter/opensearch-adapter.ts
@@ -84,6 +84,10 @@ export class OpenSearchAdapter implements SearchClientAdapter {
                 const result = await this.client.indices.putAlias({ index, name, body });
                 return { body: result.body };
             },
+            putSettings: async ({ index, body }) => {
+                const result = await this.client.indices.putSettings({ index, body });
+                return { body: result.body };
+            },
             refresh: async ({ index }) => {
                 const result = await this.client.indices.refresh({ index });
                 return { body: result.body };
diff --git a/packages/elasticsearch-plugin/src/adapter/search-client-adapter.ts b/packages/elasticsearch-plugin/src/adapter/search-client-adapter.ts
index 9f4d395..67b93e9 100644
--- a/packages/elasticsearch-plugin/src/adapter/search-client-adapter.ts
+++ b/packages/elasticsearch-plugin/src/adapter/search-client-adapter.ts
@@ -49,6 +49,7 @@ export interface SearchClientAdapter {
         getMapping(params: { index: string }): Promise<{ body: Record<string, any> }>;
         getSettings(params: { index: string }): Promise<{ body: Record<string, any> }>;
         putAlias(params: { index: string; name: string; body?: any }): Promise<{ body: any }>;
+        putSettings(params: { index: string | string[]; body: any }): Promise<{ body: any }>;
         refresh(params: { index: string | string[] }): Promise<{ body: any }>;
         updateAliases(params: { body: any }): Promise<{ body: any }>;
     };
diff --git a/packages/elasticsearch-plugin/src/indexing/indexer.controller.ts b/packages/elasticsearch-plugin/src/indexing/indexer.controller.ts
index 0c6bf74..1635176 100644
--- a/packages/elasticsearch-plugin/src/indexing/indexer.controller.ts
+++ b/packages/elasticsearch-plugin/src/indexing/indexer.controller.ts
@@ -243,11 +243,15 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
                 const variantIndexName = `${this.options.indexPrefix}${VARIANT_INDEX_NAME}`;
                 const variantIndexNameForReindex = `${VARIANT_INDEX_NAME}-reindex-${reindexTempName}`;
                 const reindexVariantAliasName = `${this.options.indexPrefix}${variantIndexNameForReindex}`;
+                const tempIndexSettings = {
+                    ...this.options.indexSettings,
+                    ...this.options.reindexIndexSettings,
+                };
                 try {
                     await createIndices(
                         this.adapter,
                         this.options.indexPrefix,
-                        this.options.indexSettings,
+                        tempIndexSettings,
                         this.options.indexMappingProperties,
                         true,
                         `-reindex-${reindexTempName}`,
@@ -279,14 +283,51 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
                         .take(this.options.reindexProductsChunkSize)
                         .getMany();
 
-                    for (const { id: productId } of productIds) {
-                        await this.updateProductsOperationsOnly(ctx, productId, variantIndexNameForReindex);
-                        finishedProductsCount++;
-                        observer.next({
-                            total: totalProductIds,
-                            completed: Math.min(finishedProductsCount, totalProductIds),
-                            duration: +new Date() - timeStart,
-                        });
+                    const concurrency = Math.max(1, this.options.reindexConcurrency);
+                    const prefetch = await this.loadProductChunkPrefetch(
+                        productIds.map(p => p.id),
+                    );
+                    if (concurrency === 1) {
+                        for (const { id: productId } of productIds) {
+                            await this.updateProductsOperationsOnly(
+                                ctx,
+                                productId,
+                                variantIndexNameForReindex,
+                                false,
+                                prefetch.get(productId),
+                            );
+                            finishedProductsCount++;
+                            observer.next({
+                                total: totalProductIds,
+                                completed: Math.min(finishedProductsCount, totalProductIds),
+                                duration: +new Date() - timeStart,
+                            });
+                        }
+                    } else {
+                        // Each worker gets its own MutableRequestContext so the
+                        // per-product channel mutation (`ctx.setChannel(channel)`)
+                        // can run in parallel without races.
+                        for (let i = 0; i < productIds.length; i += concurrency) {
+                            const window = productIds.slice(i, i + concurrency);
+                            await Promise.all(
+                                window.map(async ({ id: productId }) => {
+                                    const workerCtx = MutableRequestContext.deserialize(rawContext);
+                                    await this.updateProductsOperationsOnly(
+                                        workerCtx,
+                                        productId,
+                                        variantIndexNameForReindex,
+                                        false,
+                                        prefetch.get(productId),
+                                    );
+                                }),
+                            );
+                            finishedProductsCount += window.length;
+                            observer.next({
+                                total: totalProductIds,
+                                completed: Math.min(finishedProductsCount, totalProductIds),
+                                duration: +new Date() - timeStart,
+                            });
+                        }
                     }
 
                     skip += this.options.reindexProductsChunkSize;
@@ -294,6 +335,27 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
                     Logger.verbose(`Done ${finishedProductsCount} / ${totalProductIds} products`);
                 } while (productIds.length >= this.options.reindexProductsChunkSize);
 
+                // Restore production-grade settings on the temp index, then refresh it once
+                // before swapping the alias so search queries see a warm index immediately.
+                try {
+                    const reindexFullIndexName = await getIndexNameByAlias(
+                        this.adapter,
+                        reindexVariantAliasName,
+                    );
+                    if (reindexFullIndexName) {
+                        await this.adapter.indices.putSettings({
+                            index: reindexFullIndexName,
+                            body: this.options.reindexRestoreSettings,
+                        });
+                        await this.adapter.indices.refresh({ index: reindexFullIndexName });
+                    }
+                } catch (e: any) {
+                    Logger.error(
+                        `Could not restore index settings before alias swap: ${JSON.stringify(e)}`,
+                        loggerCtx,
+                    );
+                }
+
                 // Switch the index to the new reindexed one
                 await this.switchAlias(reindexVariantAliasName, variantIndexName);
 
@@ -312,22 +374,28 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
         chunkSize: number,
         operations: BulkVariantOperation[],
         index = VARIANT_INDEX_NAME,
+        refresh: boolean = true,
     ): Promise<void> {
         Logger.verbose(
             `Will execute ${operations.length} bulk update operations with index ${index}`,
             loggerCtx,
         );
-        let i;
-        let j;
-        let processedOperation = 0;
-        for (i = 0, j = operations.length; i < j; i += chunkSize) {
-            const operationsChunks = operations.slice(i, i + chunkSize);
-            await this.executeBulkOperations(operationsChunks, index);
-            processedOperation += operationsChunks.length;
-
-            Logger.verbose(
-                `Executing operation chunks ${processedOperation}/${operations.length}`,
-                loggerCtx,
+
+        const concurrency = refresh ? 1 : Math.max(1, this.options.reindexBulkConcurrency);
+        const chunks: BulkVariantOperation[][] = [];
+        for (let i = 0, j = operations.length; i < j; i += chunkSize) {
+            chunks.push(operations.slice(i, i + chunkSize));
+        }
+        if (concurrency === 1) {
+            for (const chunk of chunks) {
+                await this.executeBulkOperations(chunk, index, refresh);
+            }
+            return;
+        }
+        for (let i = 0; i < chunks.length; i += concurrency) {
+            const window = chunks.slice(i, i + concurrency);
+            await Promise.all(
+                window.map(chunk => this.executeBulkOperations(chunk, index, refresh)),
             );
         }
     }
@@ -500,42 +568,85 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
         }
     }
 
+    private async loadProductChunkPrefetch(
+        productIds: ID[],
+    ): Promise<Map<ID, { product: Product; variants: ProductVariant[] }>> {
+        const result = new Map<ID, { product: Product; variants: ProductVariant[] }>();
+        if (productIds.length === 0) return result;
+
+        const productRepo = this.connection.rawConnection.getRepository(Product);
+        const variantRepo = this.connection.rawConnection.getRepository(ProductVariant);
+
+        const [products, variants] = await Promise.all([
+            productRepo.find({
+                where: { id: In(productIds), deletedAt: IsNull() },
+                relations: this.productRelations,
+            }),
+            variantRepo.find({
+                where: { productId: In(productIds), deletedAt: IsNull() },
+                relations: this.variantRelations,
+                order: { id: 'ASC' },
+            }),
+        ]);
+
+        const variantsByProduct = new Map<ID, ProductVariant[]>();
+        for (const v of variants) {
+            const list = variantsByProduct.get(v.productId) ?? [];
+            list.push(v);
+            variantsByProduct.set(v.productId, list);
+        }
+
+        for (const product of products) {
+            result.set(product.id, {
+                product,
+                variants: variantsByProduct.get(product.id) ?? [],
+            });
+        }
+        return result;
+    }
+
     private async updateProductsOperationsOnly(
         ctx: MutableRequestContext,
         productId: ID,
         index = VARIANT_INDEX_NAME,
+        refresh: boolean = true,
+        prefetched?: { product: Product; variants: ProductVariant[] },
     ): Promise<void> {
         let operations: BulkVariantOperation[] = [];
-        let product: Product | undefined;
-        try {
-            product = await this.connection
-                .getRepository(ctx, Product)
-                .find({
-                    where: { id: productId, deletedAt: IsNull() },
-                    relations: this.productRelations,
-                })
-                .then(result => result[0] ?? undefined);
-        } catch (e: any) {
-            Logger.error(e.message, loggerCtx, e.stack);
-            throw e;
+        let product: Product | undefined = prefetched?.product;
+        if (!product) {
+            try {
+                product = await this.connection
+                    .getRepository(ctx, Product)
+                    .find({
+                        where: { id: productId, deletedAt: IsNull() },
+                        relations: this.productRelations,
+                    })
+                    .then(result => result[0] ?? undefined);
+            } catch (e: any) {
+                Logger.error(e.message, loggerCtx, e.stack);
+                throw e;
+            }
         }
         if (!product) {
             return;
         }
-        let updatedProductVariants: ProductVariant[] = [];
-        try {
-            updatedProductVariants = await this.connection.rawConnection.getRepository(ProductVariant).find({
-                relations: this.variantRelations,
-                where: {
-                    productId,
-                    deletedAt: IsNull(),
-                },
-                order: {
-                    id: 'ASC',
-                },
-            });
-        } catch (e: any) {
-            Logger.error(e.message, loggerCtx, e.stack);
+        let updatedProductVariants: ProductVariant[] = prefetched?.variants ?? [];
+        if (!prefetched) {
+            try {
+                updatedProductVariants = await this.connection.rawConnection.getRepository(ProductVariant).find({
+                    relations: this.variantRelations,
+                    where: {
+                        productId,
+                        deletedAt: IsNull(),
+                    },
+                    order: {
+                        id: 'ASC',
+                    },
+                });
+            } catch (e: any) {
+                Logger.error(e.message, loggerCtx, e.stack);
+            }
         }
 
         // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
@@ -552,6 +663,23 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
 
         const uniqueLanguageVariants = unique(languageVariants);
         const originalChannel = ctx.channel;
+
+        let pendingBytes = 0;
+        const sizeLimit = this.options.reindexBulkOperationSizeLimit;
+        const byteLimit = this.options.reindexBulkSizeBytes;
+        const shouldFlush = () => operations.length >= sizeLimit || pendingBytes >= byteLimit;
+        const trackBytes = (...ops: BulkVariantOperation[]) => {
+            for (const op of ops) {
+                pendingBytes += Buffer.byteLength(JSON.stringify(op.operation));
+            }
+        };
+        const flushAccumulated = async () => {
+            if (operations.length === 0) return;
+            await this.executeBulkOperationsByChunks(sizeLimit, operations, index, refresh);
+            operations = [];
+            pendingBytes = 0;
+        };
+
         for (const channel of product.channels) {
             ctx.setChannel(channel);
             const variantsInChannel = updatedProductVariants.filter(v =>
@@ -563,7 +691,7 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
             for (const languageCode of uniqueLanguageVariants) {
                 if (variantsInChannel.length) {
                     for (const variant of variantsInChannel) {
-                        operations.push(
+                        const pair: BulkVariantOperation[] = [
                             {
                                 index: VARIANT_INDEX_NAME,
                                 operation: {
@@ -588,20 +716,16 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
                                     doc_as_upsert: true,
                                 },
                             },
-                        );
+                        ];
+                        operations.push(...pair);
+                        trackBytes(...pair);
 
-                        if (operations.length >= this.options.reindexBulkOperationSizeLimit) {
-                            // Because we can have a huge amount of variant for 1 product, we also chunk update operations
-                            await this.executeBulkOperationsByChunks(
-                                this.options.reindexBulkOperationSizeLimit,
-                                operations,
-                                index,
-                            );
-                            operations = [];
+                        if (shouldFlush()) {
+                            await flushAccumulated();
                         }
                     }
                 } else {
-                    operations.push(
+                    const pair: BulkVariantOperation[] = [
                         {
                             index: VARIANT_INDEX_NAME,
                             operation: {
@@ -621,16 +745,12 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
                                 doc_as_upsert: true,
                             },
                         },
-                    );
+                    ];
+                    operations.push(...pair);
+                    trackBytes(...pair);
                 }
-                if (operations.length >= this.options.reindexBulkOperationSizeLimit) {
-                    // Because we can have a huge amount of variant for 1 product, we also chunk update operations
-                    await this.executeBulkOperationsByChunks(
-                        this.options.reindexBulkOperationSizeLimit,
-                        operations,
-                        index,
-                    );
-                    operations = [];
+                if (shouldFlush()) {
+                    await flushAccumulated();
                 }
             }
         }
@@ -641,6 +761,7 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
             this.options.reindexBulkOperationSizeLimit,
             operations,
             index,
+            refresh,
         );
 
         return;
@@ -827,19 +948,24 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
         return unique(variants.map(v => v.product.id));
     }
 
-    private async executeBulkOperations(operations: BulkVariantOperation[], indexName = VARIANT_INDEX_NAME) {
+    private async executeBulkOperations(
+        operations: BulkVariantOperation[],
+        indexName = VARIANT_INDEX_NAME,
+        refresh: boolean = true,
+    ) {
         const variantOperations: Array<BulkOperation | BulkOperationDoc<VariantIndexItem>> = [];
 
         for (const operation of operations) {
             variantOperations.push(operation.operation);
         }
 
-        return Promise.all([this.runBulkOperationsOnIndex(indexName, variantOperations)]);
+        return this.runBulkOperationsOnIndex(indexName, variantOperations, refresh);
     }
 
     private async runBulkOperationsOnIndex(
         indexName: string,
         operations: Array<BulkOperation | BulkOperationDoc<VariantIndexItem | ProductIndexItem>>,
+        refresh: boolean = true,
     ) {
         if (operations.length === 0) {
             return;
@@ -847,7 +973,7 @@ export class ElasticsearchIndexerController implements OnModuleInit, OnModuleDes
         try {
             const fullIndexName = this.options.indexPrefix + indexName;
             const { body } = await this.adapter.bulk({
-                refresh: true,
+                refresh,
                 index: fullIndexName,
                 body: operations,
             });
diff --git a/packages/elasticsearch-plugin/src/options.ts b/packages/elasticsearch-plugin/src/options.ts
index 4a852fc..e9a9ee2 100644
--- a/packages/elasticsearch-plugin/src/options.ts
+++ b/packages/elasticsearch-plugin/src/options.ts
@@ -115,6 +115,29 @@ export interface ElasticsearchOptions {
      * {}
      */
     indexSettings?: object;
+    /**
+     * @description
+     * Index settings applied to the **temporary index** used during a full reindex.
+     * Merged on top of `indexSettings`. Defaults disable refresh and replicas during
+     * the reindex bulk-load and switch translog to `async` durability — Elasticsearch's
+     * recommended bulk-load profile. The temporary index is reverted to production-grade
+     * settings (refresh_interval restored, replicas restored) and refreshed once before
+     * the alias swap, so search consumers see the new index already-warm.
+     *
+     * @default
+     * { refresh_interval: '-1', number_of_replicas: 0, translog: { durability: 'async' } }
+     */
+    reindexIndexSettings?: object;
+    /**
+     * @description
+     * Settings to restore on the temporary reindex index immediately before the alias
+     * swap. Use this to override the production refresh interval or replica count when
+     * they should differ from the defaults (`refresh_interval: 1s`, `number_of_replicas: 1`).
+     *
+     * @default
+     * { refresh_interval: '1s', number_of_replicas: 1 }
+     */
+    reindexRestoreSettings?: object;
     /**
      * @description
      * This option allow to redefine or define new properties in mapping. More about elastic
@@ -177,10 +200,47 @@ export interface ElasticsearchOptions {
      * index operations. This option sets the maximum number of operations in the memory buffer before a
      * bulk operation is executed.
      *
-     * @default 3000
+     * @default 5000
      * @since 2.1.7
      */
     reindexBulkOperationSizeLimit?: number;
+    /**
+     * @description
+     * Number of bulk requests sent in parallel during a full reindex. Higher values
+     * trade more memory + ES node load for faster reindex throughput. Set to `1` to
+     * preserve the historical sequential behaviour.
+     *
+     * @default 4
+     */
+    reindexBulkConcurrency?: number;
+    /**
+     * @description
+     * Soft byte-size limit for an individual reindex bulk payload. When the buffered
+     * operations exceed this size we flush early — this keeps each request well under
+     * the ES `http.max_content_length` limit even when individual variant docs are
+     * large (custom mappings, big translation arrays, etc). `reindexBulkOperationSizeLimit`
+     * still applies as the hard upper bound on the operation count.
+     *
+     * @default 5_000_000  (≈ 5 MB)
+     */
+    reindexBulkSizeBytes?: number;
+    /**
+     * @description
+     * Number of products processed in parallel during a full reindex. Each worker
+     * runs `updateProductsOperationsOnly` on a different `productId` against the
+     * shared temporary index. Bumping this is a large win on big catalogues — DB
+     * variant-fetch and channel/language doc-build dominate the loop, and ES has
+     * spare capacity for concurrent bulks once `refresh: false` is in play.
+     *
+     * Defaults to `1` (sequential, historical behaviour). Raising to `4`-`8` has
+     * shown 2-5× speed-ups on production-scale catalogues, but the plugin shares
+     * entity instances (notably `channels`) across products via TypeORM's identity
+     * map, so concurrent workers can race on shared entity state. Benchmark
+     * carefully and run the full e2e suite at the chosen value before deploying.
+     *
+     * @default 1
+     */
+    reindexConcurrency?: number;
     /**
      * @description
      * Configuration of the internal Elasticsearch query.
@@ -734,9 +794,21 @@ export const defaultOptions: ElasticsearchRuntimeOptions = {
     connectionAttemptInterval: 5000,
     indexPrefix: 'vendure-',
     indexSettings: {},
+    reindexIndexSettings: {
+        refresh_interval: '-1',
+        number_of_replicas: 0,
+        translog: { durability: 'async' },
+    },
+    reindexRestoreSettings: {
+        refresh_interval: '1s',
+        number_of_replicas: 1,
+    },
     indexMappingProperties: {},
     reindexProductsChunkSize: 2500,
-    reindexBulkOperationSizeLimit: 3000,
+    reindexBulkOperationSizeLimit: 5000,
+    reindexBulkConcurrency: 4,
+    reindexBulkSizeBytes: 5_000_000,
+    reindexConcurrency: 1,
     searchConfig: {
         facetValueMaxSize: 50,
         collectionMaxSize: 50,