diff --git a/model/modeldecoder/cloud.go b/model/modeldecoder/cloud.go
deleted file mode 100644
index 74d49004253..00000000000
--- a/model/modeldecoder/cloud.go
+++ /dev/null
@@ -1,46 +0,0 @@
-// Licensed to Elasticsearch B.V. under one or more contributor
-// license agreements. See the NOTICE file distributed with
-// this work for additional information regarding copyright
-// ownership. Elasticsearch B.V. licenses this file to you under
-// the Apache License, Version 2.0 (the "License"); you may
-// not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing,
-// software distributed under the License is distributed on an
-// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-// KIND, either express or implied.  See the License for the
-// specific language governing permissions and limitations
-// under the License.
-
-package modeldecoder
-
-import (
-	"github.com/elastic/apm-server/model"
-)
-
-func decodeCloud(input map[string]interface{}, out *model.Cloud) {
-	if input == nil {
-		return
-	}
-	decodeString(input, "availability_zone", &out.AvailabilityZone)
-	decodeString(input, "provider", &out.Provider)
-	decodeString(input, "region", &out.Region)
-	if account := getObject(input, "account"); account != nil {
-		decodeString(account, "id", &out.AccountID)
-		decodeString(account, "name", &out.AccountName)
-	}
-	if instance := getObject(input, "instance"); instance != nil {
-		decodeString(instance, "id", &out.InstanceID)
-		decodeString(instance, "name", &out.InstanceName)
-	}
-	if machine := getObject(input, "machine"); machine != nil {
-		decodeString(machine, "type", &out.MachineType)
-	}
-	if project := getObject(input, "project"); project != nil {
-		decodeString(project, "id", &out.ProjectID)
-		decodeString(project, "name", &out.ProjectName)
-	}
-}
diff --git a/model/modeldecoder/generator/generator.go b/model/modeldecoder/generator/generator.go
index 89518cf5b9c..f2f684d774d 100644
--- a/model/modeldecoder/generator/generator.go
+++ b/model/modeldecoder/generator/generator.go
@@ -314,7 +314,7 @@ if !%s.MatchString(k){
 			if types, ok := parts[ruleTypesVals]; ok {
 				delete(parts, ruleTypesVals)
 				fmt.Fprintf(&g.buf, `
-switch v.(type){
+switch t := v.(type){
 `[1:])
 				if !required {
 					fmt.Fprintf(&g.buf, `
@@ -335,7 +335,7 @@ case %s:
 						if maxVal, ok := parts[ruleMaxVals]; ok {
 							delete(parts, ruleMaxVals)
 							fmt.Fprintf(&g.buf, `
-if utf8.RuneCountInString(v.(string)) > %s{
+if utf8.RuneCountInString(t) > %s{
 	return fmt.Errorf("validation rule '%s(%s)' violated for '%s'")
 }
 `[1:], maxVal, ruleMaxVals, maxVal, flattenedName)
@@ -469,7 +469,7 @@ if m.%s.IsNil(){
 }
 func jsonName(f structField) string {
 	parts := parseTag(f.tag, "json")
-	if parts == nil || len(parts) == 0 {
+	if len(parts) == 0 {
 		return strings.ToLower(f.name)
 	}
 	return parts[0]
diff --git a/model/modeldecoder/rumv3/decoder.go b/model/modeldecoder/rumv3/decoder.go
index bc80367069a..9c6061acc8e 100644
--- a/model/modeldecoder/rumv3/decoder.go
+++ b/model/modeldecoder/rumv3/decoder.go
@@ -51,7 +51,7 @@ func DecodeMetadata(d decoder.Decoder, out *model.Metadata) error {
 	if err := d.Decode(&m); err != nil {
 		return err
 	}
-	if err := m.Metadata.validate(); err != nil {
+	if err := m.validate(); err != nil {
 		return err
 	}
 	mapToModel(&m.Metadata, out)
diff --git a/model/modeldecoder/rumv3/model_generated.go b/model/modeldecoder/rumv3/model_generated.go
index 947255f70c3..a2e1b9bb032 100644
--- a/model/modeldecoder/rumv3/model_generated.go
+++ b/model/modeldecoder/rumv3/model_generated.go
@@ -61,10 +61,10 @@ func (m *metadata) validate() error {
 		if !labelsRegex.MatchString(k) {
 			return fmt.Errorf("validation rule 'patternKeys(labelsRegex)' violated for 'm.l'")
 		}
-		switch v.(type) {
+		switch t := v.(type) {
 		case nil:
 		case string:
-			if utf8.RuneCountInString(v.(string)) > 1024 {
+			if utf8.RuneCountInString(t) > 1024 {
 				return fmt.Errorf("validation rule 'maxVals(1024)' violated for 'm.l'")
 			}
 		case bool:
diff --git a/model/modeldecoder/typ/typ.go b/model/modeldecoder/typ/typ.go
index dbb56dbd46a..d7a071e8115 100644
--- a/model/modeldecoder/typ/typ.go
+++ b/model/modeldecoder/typ/typ.go
@@ -53,8 +53,6 @@ func init() {
 
 }
 
-var json = jsoniter.ConfigCompatibleWithStandardLibrary
-
 type String struct {
 	Val   string
 	isSet bool
diff --git a/model/modeldecoder/v2/decoder.go b/model/modeldecoder/v2/decoder.go
index 864e3f392c1..226e8a40a70 100644
--- a/model/modeldecoder/v2/decoder.go
+++ b/model/modeldecoder/v2/decoder.go
@@ -22,16 +22,14 @@ import (
 	"net"
 	"sync"
 
-	"github.com/minio/simdjson-go"
-
 	"github.com/elastic/apm-server/decoder"
 	"github.com/elastic/apm-server/model"
 	"github.com/elastic/beats/v7/libbeat/common"
 )
 
-var (
-	simdjsonSupported = simdjson.SupportedCPU()
-)
+// var (
+// simdjsonSupported = simdjson.SupportedCPU()
+// )
 
 func init() {
 	metadataPool.New = func() interface{} {
diff --git a/model/modeldecoder/v2/model_generated.go b/model/modeldecoder/v2/model_generated.go
index c3a9d2789f7..a879dd70f2d 100644
--- a/model/modeldecoder/v2/model_generated.go
+++ b/model/modeldecoder/v2/model_generated.go
@@ -67,10 +67,10 @@ func (m *metadata) validate() error {
 		if !labelsRegex.MatchString(k) {
 			return fmt.Errorf("validation rule 'patternKeys(labelsRegex)' violated for 'metadata.labels'")
 		}
-		switch v.(type) {
+		switch t := v.(type) {
 		case nil:
 		case string:
-			if utf8.RuneCountInString(v.(string)) > 1024 {
+			if utf8.RuneCountInString(t) > 1024 {
 				return fmt.Errorf("validation rule 'maxVals(1024)' violated for 'metadata.labels'")
 			}
 		case bool:
diff --git a/model/modeldecoder/v2/simdjson.go b/model/modeldecoder/v2/simdjson.go
index 43e259f28f4..6e85fa7e565 100644
--- a/model/modeldecoder/v2/simdjson.go
+++ b/model/modeldecoder/v2/simdjson.go
@@ -17,518 +17,520 @@
 
 package v2
 
-import (
-	"errors"
-	"fmt"
-	"sync"
+// comment for now to make check-full cmd happy
 
-	"github.com/minio/simdjson-go"
+// import (
+// 	"errors"
+// 	"fmt"
+// 	"sync"
 
-	"github.com/elastic/apm-server/decoder"
-)
+// 	"github.com/minio/simdjson-go"
 
-func init() {
-	elemsPool.New = func() interface{} {
-		elems := simdjson.Elements{
-			Elements: make([]simdjson.Element, 0, 5),
-			Index:    make(map[string]int, 5),
-		}
-		return &elems
-	}
-	objPool.New = func() interface{} {
-		return &simdjson.Object{}
-	}
-	parsedJSONPool.New = func() interface{} {
-		return &simdjson.ParsedJson{}
-	}
-	iterPool.New = func() interface{} {
-		return &simdjson.Iter{}
-	}
-}
+// 	"github.com/elastic/apm-server/decoder"
+// )
 
-var elemsPool, iterPool, objPool, parsedJSONPool sync.Pool
+// func init() {
+// 	elemsPool.New = func() interface{} {
+// 		elems := simdjson.Elements{
+// 			Elements: make([]simdjson.Element, 0, 5),
+// 			Index:    make(map[string]int, 5),
+// 		}
+// 		return &elems
+// 	}
+// 	objPool.New = func() interface{} {
+// 		return &simdjson.Object{}
+// 	}
+// 	parsedJSONPool.New = func() interface{} {
+// 		return &simdjson.ParsedJson{}
+// 	}
+// 	iterPool.New = func() interface{} {
+// 		return &simdjson.Iter{}
+// 	}
+// }
 
-func simdjsonDecodeEmbeddedMetadata(d decoder.Decoder, out *metadata) error {
-	return simdjsonDecodeWrappedErr(d, "", out)
-}
-func simdjsonDecodeNestedMetadata(d decoder.Decoder, out *metadata) error {
-	return simdjsonDecodeWrappedErr(d, "metadata", out)
-}
+// var elemsPool, iterPool, objPool, parsedJSONPool sync.Pool
 
-//TODO(simitt): look into more human readable error messages
-func simdjsonDecodeWrappedErr(d decoder.Decoder, rootKey string, out *metadata) error {
-	if err := simdjsonDecode(d, rootKey, out); err != nil {
-		if err == decoder.ErrLineTooLong {
-			return err
-		}
-		return decoder.JSONDecodeError("data read error: " + err.Error())
-	}
-	return nil
-}
+// func simdjsonDecodeEmbeddedMetadata(d decoder.Decoder, out *metadata) error {
+// 	return simdjsonDecodeWrappedErr(d, "", out)
+// }
+// func simdjsonDecodeNestedMetadata(d decoder.Decoder, out *metadata) error {
+// 	return simdjsonDecodeWrappedErr(d, "metadata", out)
+// }
 
-func simdjsonDecode(d decoder.Decoder, rootKey string, out interface{}) error {
-	line, err := d.Read()
-	if err != nil {
-		return err
-	}
-	reusedJSON := parsedJSONPool.Get().(*simdjson.ParsedJson)
-	defer parsedJSONPool.Put(reusedJSON)
-	parsedJSON, err := simdjson.Parse(line, reusedJSON)
-	defer parsedJSONPool.Put(parsedJSON)
-	if err != nil {
-		return err
-	}
-	obj := objPool.Get().(*simdjson.Object)
-	defer objPool.Put(obj)
-	tmpIter := iterPool.Get().(*simdjson.Iter)
-	defer iterPool.Put(tmpIter)
-	if err := rootObj(parsedJSON.Iter(), tmpIter, obj); err != nil {
-		return err
-	}
-	if rootKey != "" {
-		if err := keyObject(obj, rootKey); err != nil {
-			return err
-		}
-	}
+// //TODO(simitt): look into more human readable error messages
+// func simdjsonDecodeWrappedErr(d decoder.Decoder, rootKey string, out *metadata) error {
+// 	if err := simdjsonDecode(d, rootKey, out); err != nil {
+// 		if err == decoder.ErrLineTooLong {
+// 			return err
+// 		}
+// 		return decoder.JSONDecodeError("data read error: " + err.Error())
+// 	}
+// 	return nil
+// }
 
-	if err := decodeElements(obj, "", out); err != nil {
-		return err
-	}
-	return nil
-}
+// func simdjsonDecode(d decoder.Decoder, rootKey string, out interface{}) error {
+// 	line, err := d.Read()
+// 	if err != nil {
+// 		return err
+// 	}
+// 	reusedJSON := parsedJSONPool.Get().(*simdjson.ParsedJson)
+// 	defer parsedJSONPool.Put(reusedJSON)
+// 	parsedJSON, err := simdjson.Parse(line, reusedJSON)
+// 	defer parsedJSONPool.Put(parsedJSON)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	obj := objPool.Get().(*simdjson.Object)
+// 	defer objPool.Put(obj)
+// 	tmpIter := iterPool.Get().(*simdjson.Iter)
+// 	defer iterPool.Put(tmpIter)
+// 	if err := rootObj(parsedJSON.Iter(), tmpIter, obj); err != nil {
+// 		return err
+// 	}
+// 	if rootKey != "" {
+// 		if err := keyObject(obj, rootKey); err != nil {
+// 			return err
+// 		}
+// 	}
 
-func rootObj(iter simdjson.Iter, tmpIter *simdjson.Iter, obj *simdjson.Object) error {
-	iter.Advance()
-	typ, _, err := iter.Root(tmpIter)
-	if err != nil {
-		return err
-	}
-	if typ != simdjson.TypeObject {
-		err = errors.New("element not an object")
-		return err
-	}
-	obj, err = tmpIter.Object(obj)
-	if obj == nil {
-		return errors.New("object not found")
-	}
-	return err
-}
+// 	if err := decodeElements(obj, "", out); err != nil {
+// 		return err
+// 	}
+// 	return nil
+// }
 
-func keyObject(obj *simdjson.Object, key string) error {
-	elem := obj.FindKey(key, nil)
-	if elem == nil || elem.Type != simdjson.TypeObject {
-		return fmt.Errorf("object with key %v not found", key)
-	}
-	obj, err := elem.Iter.Object(obj)
-	if err != nil {
-		return err
-	}
-	if obj == nil {
-		return errors.New("object not found")
-	}
-	return err
-}
+// func rootObj(iter simdjson.Iter, tmpIter *simdjson.Iter, obj *simdjson.Object) error {
+// 	iter.Advance()
+// 	typ, _, err := iter.Root(tmpIter)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	if typ != simdjson.TypeObject {
+// 		err = errors.New("element not an object")
+// 		return err
+// 	}
+// 	obj, err = tmpIter.Object(obj)
+// 	if obj == nil {
+// 		return errors.New("object not found")
+// 	}
+// 	return err
+// }
 
-func decodeElements(obj *simdjson.Object, key string, out interface{}) error {
-	elems := elemsPool.Get().(*simdjson.Elements)
-	defer elemsPool.Put(elems)
-	_, err := obj.Parse(elems)
-	if err != nil {
-		return err
-	}
-	for _, elem := range elems.Elements {
-		s := elem.Name
-		//TODO(simitt): improve this by using knowledge about keys
-		if key != "" {
-			s = fmt.Sprintf("%s.%s", key, s)
-		}
-		switch elem.Type {
-		case simdjson.TypeObject:
-			//TODO(simitt): improve this
-			if elem.Name == "labels" {
-				if err := elementToDecoderModel(s, elem, out); err != nil {
-					return err
-				}
-			} else {
-				elemObj, err := elem.Iter.Object(nil)
-				if err != nil {
-					return err
-				}
-				if err := decodeElements(elemObj, s, out); err != nil {
-					return err
-				}
-			}
-		default:
-			if err := elementToDecoderModel(s, elem, out); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
+// func keyObject(obj *simdjson.Object, key string) error {
+// 	elem := obj.FindKey(key, nil)
+// 	if elem == nil || elem.Type != simdjson.TypeObject {
+// 		return fmt.Errorf("object with key %v not found", key)
+// 	}
+// 	obj, err := elem.Iter.Object(obj)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	if obj == nil {
+// 		return errors.New("object not found")
+// 	}
+// 	return err
+// }
 
-//TODO(simitt): to be generated from json tags and datatypes
-func elementToDecoderModel(key string, elem simdjson.Element, out interface{}) error {
-	switch typ := out.(type) {
-	case *metadata:
-		return elementToMetadata(key, elem, typ)
-	}
-	return nil
-}
+// func decodeElements(obj *simdjson.Object, key string, out interface{}) error {
+// 	elems := elemsPool.Get().(*simdjson.Elements)
+// 	defer elemsPool.Put(elems)
+// 	_, err := obj.Parse(elems)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	for _, elem := range elems.Elements {
+// 		s := elem.Name
+// 		//TODO(simitt): improve this by using knowledge about keys
+// 		if key != "" {
+// 			s = fmt.Sprintf("%s.%s", key, s)
+// 		}
+// 		switch elem.Type {
+// 		case simdjson.TypeObject:
+// 			//TODO(simitt): improve this
+// 			if elem.Name == "labels" {
+// 				if err := elementToDecoderModel(s, elem, out); err != nil {
+// 					return err
+// 				}
+// 			} else {
+// 				elemObj, err := elem.Iter.Object(nil)
+// 				if err != nil {
+// 					return err
+// 				}
+// 				if err := decodeElements(elemObj, s, out); err != nil {
+// 					return err
+// 				}
+// 			}
+// 		default:
+// 			if err := elementToDecoderModel(s, elem, out); err != nil {
+// 				return err
+// 			}
+// 		}
+// 	}
+// 	return nil
+// }
 
-//TODO(simitt): do not ignore type validation, see https://github.com/elastic/apm-server/pull/4076#discussion_r476987351
-func elementToMetadata(key string, elem simdjson.Element, m *metadata) error {
-	switch key {
-	case "cloud.account.id":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Account.ID.Set(v)
-		}
-	case "cloud.account.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Account.Name.Set(v)
-		}
-	case "cloud.availability_zone":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.AvailabilityZone.Set(v)
-		}
-	case "cloud.instance.id":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Instance.ID.Set(v)
-		}
-	case "cloud.instance.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Instance.Name.Set(v)
-		}
-	case "cloud.machine.type":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Machine.Type.Set(v)
-		}
-	case "cloud.project.id":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Project.ID.Set(v)
-		}
-	case "cloud.project.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Project.Name.Set(v)
-		}
-	case "cloud.provider":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Provider.Set(v)
-		}
-	case "cloud.region":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Cloud.Region.Set(v)
-		}
-	case "labels":
-		if elem.Type == simdjson.TypeObject {
-			v, err := elem.Iter.Interface()
-			if err != nil {
-				return err
-			}
-			if vMap, ok := v.(map[string]interface{}); ok {
-				m.Labels = vMap
-			} else {
-				return errors.New("decoding labels failed")
-			}
-		}
-	case "process.pid":
-		if elem.Type == simdjson.TypeInt {
-			v, err := elem.Iter.Int()
-			if err != nil {
-				return err
-			}
-			m.Process.Pid.Set(int(v))
-		}
-	case "process.ppid":
-		if elem.Type == simdjson.TypeInt {
-			v, err := elem.Iter.Int()
-			if err != nil {
-				return err
-			}
-			m.Process.Ppid.Set(int(v))
-		}
-	case "process.title":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Process.Title.Set(v)
-		}
-	case "process.argv":
-		if elem.Type == simdjson.TypeArray {
-			v, err := elem.Iter.Array(nil)
-			if err != nil {
-				return err
-			}
-			vStr, err := v.AsString()
-			if err != nil {
-				return err
-			}
-			m.Process.Argv = vStr
-		}
-	case "service.agent.ephemeral_id":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Agent.EphemeralID.Set(v)
-		}
-	case "service.agent.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Agent.Name.Set(v)
-		}
-	case "service.agent.version":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Agent.Version.Set(v)
-		}
-	case "service.environment":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Environment.Set(v)
-		}
-	case "service.framework.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Framework.Name.Set(v)
-		}
-	case "service.framework.version":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Framework.Version.Set(v)
-		}
-	case "service.language.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Language.Name.Set(v)
-		}
-	case "service.language.version":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Language.Version.Set(v)
-		}
-	case "service.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Name.Set(v)
-		}
-	case "service.node.configured_name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Node.Name.Set(v)
-		}
-	case "service.runtime.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Runtime.Name.Set(v)
-		}
-	case "service.runtime.version":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Runtime.Version.Set(v)
-		}
-	case "service.version":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.Service.Version.Set(v)
-		}
-	case "system.architecture":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Architecture.Set(v)
-		}
-	case "system.configured_hostname":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.ConfiguredHostname.Set(v)
-		}
-	case "system.container.id":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Container.ID.Set(v)
-		}
-	case "system.detected_hostname":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.DetectedHostname.Set(v)
-		}
-	case "system.hostname":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.HostnameDeprecated.Set(v)
-		}
-	case "system.ip":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.IP.Set(v)
-		}
-	case "system.kubernetes.namespace":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Kubernetes.Namespace.Set(v)
-		}
-	case "system.kubernetes.node.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Kubernetes.Node.Name.Set(v)
-		}
-	case "system.kubernetes.pod.name":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Kubernetes.Pod.Name.Set(v)
-		}
-	case "system.kubernetes.pod.uid":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Kubernetes.Pod.UID.Set(v)
-		}
-	case "system.platform":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.System.Platform.Set(v)
-		}
-	case "user.id":
-		var v interface{}
-		var err error
-		switch elem.Type {
-		case simdjson.TypeString:
-			v, err = elem.Iter.String()
-		case simdjson.TypeInt:
-			v, err = elem.Iter.Int()
-		}
-		if err != nil {
-			return err
-		}
-		m.User.ID.Set(v)
-	case "user.email":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.User.Email.Set(v)
-		}
-	case "user.username":
-		if elem.Type == simdjson.TypeString {
-			v, err := elem.Iter.String()
-			if err != nil {
-				return err
-			}
-			m.User.Name.Set(v)
-		}
-	}
+// //TODO(simitt): to be generated from json tags and datatypes
+// func elementToDecoderModel(key string, elem simdjson.Element, out interface{}) error {
+// 	switch typ := out.(type) {
+// 	case *metadata:
+// 		return elementToMetadata(key, elem, typ)
+// 	}
+// 	return nil
+// }
 
-	return nil
-}
+// //TODO(simitt): do not ignore type validation, see https://github.com/elastic/apm-server/pull/4076#discussion_r476987351
+// func elementToMetadata(key string, elem simdjson.Element, m *metadata) error {
+// 	switch key {
+// 	case "cloud.account.id":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Account.ID.Set(v)
+// 		}
+// 	case "cloud.account.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Account.Name.Set(v)
+// 		}
+// 	case "cloud.availability_zone":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.AvailabilityZone.Set(v)
+// 		}
+// 	case "cloud.instance.id":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Instance.ID.Set(v)
+// 		}
+// 	case "cloud.instance.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Instance.Name.Set(v)
+// 		}
+// 	case "cloud.machine.type":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Machine.Type.Set(v)
+// 		}
+// 	case "cloud.project.id":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Project.ID.Set(v)
+// 		}
+// 	case "cloud.project.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Project.Name.Set(v)
+// 		}
+// 	case "cloud.provider":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Provider.Set(v)
+// 		}
+// 	case "cloud.region":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Cloud.Region.Set(v)
+// 		}
+// 	case "labels":
+// 		if elem.Type == simdjson.TypeObject {
+// 			v, err := elem.Iter.Interface()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			if vMap, ok := v.(map[string]interface{}); ok {
+// 				m.Labels = vMap
+// 			} else {
+// 				return errors.New("decoding labels failed")
+// 			}
+// 		}
+// 	case "process.pid":
+// 		if elem.Type == simdjson.TypeInt {
+// 			v, err := elem.Iter.Int()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Process.Pid.Set(int(v))
+// 		}
+// 	case "process.ppid":
+// 		if elem.Type == simdjson.TypeInt {
+// 			v, err := elem.Iter.Int()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Process.Ppid.Set(int(v))
+// 		}
+// 	case "process.title":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Process.Title.Set(v)
+// 		}
+// 	case "process.argv":
+// 		if elem.Type == simdjson.TypeArray {
+// 			v, err := elem.Iter.Array(nil)
+// 			if err != nil {
+// 				return err
+// 			}
+// 			vStr, err := v.AsString()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Process.Argv = vStr
+// 		}
+// 	case "service.agent.ephemeral_id":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Agent.EphemeralID.Set(v)
+// 		}
+// 	case "service.agent.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Agent.Name.Set(v)
+// 		}
+// 	case "service.agent.version":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Agent.Version.Set(v)
+// 		}
+// 	case "service.environment":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Environment.Set(v)
+// 		}
+// 	case "service.framework.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Framework.Name.Set(v)
+// 		}
+// 	case "service.framework.version":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Framework.Version.Set(v)
+// 		}
+// 	case "service.language.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Language.Name.Set(v)
+// 		}
+// 	case "service.language.version":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Language.Version.Set(v)
+// 		}
+// 	case "service.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Name.Set(v)
+// 		}
+// 	case "service.node.configured_name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Node.Name.Set(v)
+// 		}
+// 	case "service.runtime.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Runtime.Name.Set(v)
+// 		}
+// 	case "service.runtime.version":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Runtime.Version.Set(v)
+// 		}
+// 	case "service.version":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.Service.Version.Set(v)
+// 		}
+// 	case "system.architecture":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Architecture.Set(v)
+// 		}
+// 	case "system.configured_hostname":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.ConfiguredHostname.Set(v)
+// 		}
+// 	case "system.container.id":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Container.ID.Set(v)
+// 		}
+// 	case "system.detected_hostname":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.DetectedHostname.Set(v)
+// 		}
+// 	case "system.hostname":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.HostnameDeprecated.Set(v)
+// 		}
+// 	case "system.ip":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.IP.Set(v)
+// 		}
+// 	case "system.kubernetes.namespace":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Kubernetes.Namespace.Set(v)
+// 		}
+// 	case "system.kubernetes.node.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Kubernetes.Node.Name.Set(v)
+// 		}
+// 	case "system.kubernetes.pod.name":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Kubernetes.Pod.Name.Set(v)
+// 		}
+// 	case "system.kubernetes.pod.uid":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Kubernetes.Pod.UID.Set(v)
+// 		}
+// 	case "system.platform":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.System.Platform.Set(v)
+// 		}
+// 	case "user.id":
+// 		var v interface{}
+// 		var err error
+// 		switch elem.Type {
+// 		case simdjson.TypeString:
+// 			v, err = elem.Iter.String()
+// 		case simdjson.TypeInt:
+// 			v, err = elem.Iter.Int()
+// 		}
+// 		if err != nil {
+// 			return err
+// 		}
+// 		m.User.ID.Set(v)
+// 	case "user.email":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.User.Email.Set(v)
+// 		}
+// 	case "user.username":
+// 		if elem.Type == simdjson.TypeString {
+// 			v, err := elem.Iter.String()
+// 			if err != nil {
+// 				return err
+// 			}
+// 			m.User.Name.Set(v)
+// 		}
+// 	}
+
+// 	return nil
+// }