diff --git a/DesignHashSet.py b/DesignHashSet.py
new file mode 100644
index 00000000..ee219319
--- /dev/null
+++ b/DesignHashSet.py
@@ -0,0 +1,28 @@
+# This approach uses an array of fixed size and maps each key to an index using a hash function (key % size).
+# Each index stores a bucket to handle collisions using chaining.
+# All operations: add, remove, contains—run in O(1) average time because each bucket stays small.
+
+class MyHashSet:
+
+    def __init__(self):
+        self.size = 1000
+        self.buckets = [[] for _ in range(self.size)]
+
+    def _hash(self, key):
+        return key % self.size
+
+    def add(self, key: int) -> None:
+        idx = self._hash(key)
+        bucket = self.buckets[idx]
+        if key not in bucket:
+            bucket.append(key)
+
+    def remove(self, key: int) -> None:
+        idx = self._hash(key)
+        bucket = self.buckets[idx]
+        if key in bucket:
+            bucket.remove(key)
+
+    def contains(self, key: int) -> bool:
+        idx = self._hash(key)
+        return key in self.buckets[idx]