diff --git a/include/matador/query/insert_query_builder.hpp b/include/matador/query/insert_query_builder.hpp
index 4e351e1..14f5882 100644
--- a/include/matador/query/insert_query_builder.hpp
+++ b/include/matador/query/insert_query_builder.hpp
@@ -4,6 +4,7 @@
 #include <utility>
 
 #include "matador/object/collection.hpp"
+#include "matador/object/object_ptr.hpp"
 
 #include "matador/query/basic_schema.hpp"
 #include "matador/query/intermediates/executable_query.hpp"
@@ -56,38 +57,117 @@ private:
   std::string join_column_;
 };
 
-template<class ObjectType>
-class insert_query_builder {
+template<class EntityType>
+static std::pair<std::type_index, const void *> make_visit_key(const EntityType &ptr) {
+  return {std::type_index(typeid(EntityType)), static_cast<const void *>(&ptr)};
+}
+
+struct visit_key_hash {
+  size_t operator()(const std::pair<std::type_index, const void *> &p) const noexcept {
+    // combine hashes (simple + sufficient here)
+    const size_t h1 = p.first.hash_code();
+    const size_t h2 = std::hash<const void *>{}(p.second);
+    return h1 ^ (h2 + 0x9e3779b97f4a7c15ULL + (h1 << 6) + (h1 >> 2));
+  }
+};
+
+struct processing_many_to_many_key {
+  std::string id;
+  std::type_index local_type{typeid(void)};
+  std::type_index foreign_type{typeid(void)};
+  bool operator==(processing_many_to_many_key const &other) const {
+    return local_type == other.local_type && foreign_type == other.foreign_type && id == other.id;
+  }
+};
+
+template<class LocalType, typename ForeignType>
+static processing_many_to_many_key make_processing_many_to_many_key(const std::string &id) {
+  return {id, std::type_index(typeid(LocalType)), std::type_index(typeid(ForeignType))};
+}
+
+struct processing_many_to_many_key_hash {
+  size_t operator()(const processing_many_to_many_key &p) const noexcept {
+    size_t seed = std::hash<std::type_index>{}(p.local_type);
+
+    const size_t foreign_hash = std::hash<std::type_index>{}(p.foreign_type);
+    seed ^= foreign_hash + 0x9e3779b97f4a7c15ULL + (seed << 6) + (seed >> 2);
+
+    const size_t id_hash = std::hash<std::string>{}(p.id);
+    seed ^= id_hash + 0x9e3779b97f4a7c15ULL + (seed << 6) + (seed >> 2);
+
+    return seed;
+  }
+};
+
+struct insert_context {
+  const basic_schema &schema_;
+  const std::unordered_map<std::type_index, query_contexts> &contexts_by_type_;
+
+  std::vector<std::unique_ptr<insert_step>> steps_;
+  std::vector<std::unique_ptr<insert_step>> relation_steps_;
+  std::unordered_set<std::pair<std::type_index, const void *>, visit_key_hash> visited_;
+  std::unordered_set<processing_many_to_many_key, processing_many_to_many_key_hash> processing_many_to_many_relations_;
+
+};
+
+template < typename ObjectType >
+class insert_step_processor {
 public:
-  explicit insert_query_builder(const basic_schema &schema, const std::unordered_map<std::type_index, query_contexts> &contexts_by_type)
-  : schema_(schema)
-  , contexts_by_type_{contexts_by_type}
+  explicit insert_step_processor(insert_context &ctx)
+  : ctx_{ctx}
   {}
 
-  utils::result<std::vector<std::unique_ptr<insert_step>>, utils::error> build(const object::object_ptr<ObjectType> &ptr) {
-    if (const auto it = schema_.find(typeid(ObjectType)); it == schema_.end()) {
-      return utils::failure(utils::error{error_code::UnknownType, "Unknown type for insert query"});
+  utils::result<void, utils::error> build(object::object_ptr<ObjectType> ptr) {
+    if (!ptr) {
+      return utils::failure(utils::error{error_code::InvalidObject, "Object is null"});
     }
-
-    relation_steps_.clear();
-    processing_many_to_many_relations_.clear();
-    steps_.clear();
-    visited_.clear();
-
     ptr_ = ptr;
-    const auto result = build_insert_steps(ptr, steps_);
+
+    const auto key = make_visit_key<ObjectType>(*ptr_);
+    if (ctx_.visited_.find(key) != ctx_.visited_.end()) {
+      return utils::ok<void>();
+    }
+    ctx_.visited_.insert(key);
+
+    const auto it = ctx_.schema_.find(typeid(ObjectType));
+    if (it == ctx_.schema_.end()) {
+      return utils::failure(utils::error{error_code::UnknownType, "Unknown type"});
+    }
+
+    // 1) Traverse relations first => dependencies will be inserted before this object
+    try {
+      access::process(*this, *ptr_);
+
+      // relation inserts must run after all entity inserts were collected
+      for (auto &s : ctx_.relation_steps_) {
+        ctx_.steps_.push_back(std::move(s));
+      }
+      ctx_.relation_steps_.clear();
+    } catch (const query_builder_exception &ex) {
+      return utils::failure(ex.error());
+    }
+
+    // 2) Build INSERT for this object
+    const auto &info = it->second.node().info();
+    if (!info.has_primary_key() || it->second.pk_generator().type() == utils::generator_type::None) {
+      return utils::failure(utils::error{error_code::MissingPrimaryKey, "Type " + info.name() + " has no primary key"});
+    }
+    const auto cit = ctx_.contexts_by_type_.find(it->second.node().info().type_index());
+    if (cit == ctx_.contexts_by_type_.end()) {
+      return utils::failure(utils::error{error_code::UnknownType, "Unknown type"});
+    }
+
+    if (it->second.pk_generator().type() == utils::generator_type::Manual) {
+      ctx_.steps_.push_back(std::make_unique<insert_step_pk_manual<ObjectType>>(cit->second.insert, ptr_));
+    } else if (it->second.pk_generator().type() == utils::generator_type::Identity) {
+      ctx_.steps_.push_back(std::make_unique<insert_step_pk_identity<ObjectType>>(cit->second.insert, ptr_, info.primary_key_attribute()->name()));
+    } else {
+      ctx_.steps_.push_back(std::make_unique<insert_step_pk_generated<ObjectType>>(cit->second.insert, ptr_, it->second.pk_generator()));
+    }
+
     ptr_.reset();
-    if (!result) {
-      return utils::failure(result.err());
-    }
 
-    // relation inserts must run after all entity inserts were collected
-    for (auto &s : relation_steps_) {
-      steps_.push_back(std::move(s));
-    }
-    relation_steps_.clear();
-
-    return utils::ok(std::move(steps_));
+    return utils::ok<void>();
   }
 
   template < class PrimaryKeyType >
@@ -105,6 +185,7 @@ public:
   void on_has_one(const char * /*id*/, Pointer &obj, const char * /*join_column*/, const utils::foreign_attributes &attr) {
     on_foreign_object(obj, attr);
   }
+
   template<class CollectionType>
   void on_has_many(const char * /*id*/,
                    object::collection<object::object_ptr<CollectionType>> &objects,
@@ -118,12 +199,17 @@ public:
     }
 
     has_many_linker<ObjectType> linker(ptr_, join_column);
+    insert_context ctx{ctx_.schema_, ctx_.contexts_by_type_};
+    insert_step_processor<CollectionType> processor{ctx};
     for (auto &obj : objects) {
-      if (obj.is_transient()) {
-        const auto result = build_insert_steps(obj, relation_steps_);
-        if (!result) {
-          throw query_builder_exception(error_code::InvalidObject, "Invalid object");
-        }
+      if (!obj.is_transient()) {
+        continue;
+      }
+
+      const auto result = processor.build(obj);
+      if (!result) {
+        throw query_builder_exception(error_code::InvalidObject, "Invalid object");
+        // return utils::failure(result.err());
       }
 
       access::process(linker, *obj);
@@ -142,8 +228,8 @@ public:
       return;
     }
 
-    const auto it = schema_.find(std::string{id});
-    if (it == schema_.end()) {
+    const auto it = ctx_.schema_.find(std::string{id});
+    if (it == ctx_.schema_.end()) {
       throw query_builder_exception(error_code::UnknownType, "Unknown type " + std::string{id});
     }
 
@@ -152,29 +238,40 @@ public:
       throw query_builder_exception(error_code::InvalidRelationType, "Invalid relation type");
     }
 
-    const auto cit = contexts_by_type_.find(it->second.node().info().type_index());
-    if (cit == contexts_by_type_.end()) {
+    const auto cit = ctx_.contexts_by_type_.find(it->second.node().info().type_index());
+    if (cit == ctx_.contexts_by_type_.end()) {
       throw query_builder_exception(error_code::UnknownType, "Unknown type" + std::string{id});
     }
 
     for (auto &obj : objects) {
       auto rel = object::make_object<relation_value_type>(join_column, "value", ptr_, obj);
 
-      relation_steps_.push_back(std::make_unique<insert_step_relation<relation_value_type>>(cit->second.insert, rel));
+      ctx_.relation_steps_.push_back(std::make_unique<insert_step_relation<relation_value_type>>(cit->second.insert, rel));
     }
   }
 
-  template<class ForeignType>
-  void on_has_many_to_many(const char *id, object::collection<object::object_ptr<ForeignType>> &objects, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr) {
+    template<class ForeignType>
+    void on_has_many_to_many(const char *id,
+                             object::collection<object::object_ptr<ForeignType>> &objects,
+                             const char *join_column,
+                             const char *inverse_join_column,
+                             const utils::foreign_attributes &attr) {
     if (id == nullptr || join_column == nullptr || inverse_join_column == nullptr) {
       return;
     }
 
     using relation_value_type = object::many_to_many_relation<ObjectType, ForeignType>;
+    const std::type_index foreign_type{typeid(ForeignType)};
+    const std::type_index local_type{typeid(ObjectType)};
     insert_many_to_many_relations<relation_value_type>(
       id,
       objects,
       attr,
+      [foreign_type, local_type](const char* relation_name) -> processing_many_to_many_key {
+        std::cout << "Processing many-to-many relation: " << local_type.name() << ":" << foreign_type.name() << ":" << relation_name << std::endl;
+        return {std::string{relation_name}, local_type, foreign_type};
+        // return make_processing_many_to_many_key<ObjectType, ForeignType>(relation_name);
+      },
       [this, join_column, inverse_join_column](const auto &obj) {
         return object::make_object<relation_value_type>(join_column, inverse_join_column, ptr_, obj);
       });
@@ -193,90 +290,56 @@ public:
     }
 
     using relation_value_type = object::many_to_many_relation<ForeignType, ObjectType>;
+    const std::type_index foreign_type{typeid(ForeignType)};
+    const std::type_index local_type{typeid(ObjectType)};
     insert_many_to_many_relations<relation_value_type>(
       id,
       objects,
       attr,
+      [foreign_type, local_type](const char* relation_name) -> processing_many_to_many_key {
+        std::cout << "Processing many-to-many relation: " << foreign_type.name() << ":" << local_type.name() << ":" << relation_name << std::endl;
+        return {std::string{relation_name}, foreign_type, local_type};
+        return make_processing_many_to_many_key<ForeignType, ObjectType>(relation_name);
+      },
       [this, join_columns = std::move(join_columns)](const auto &obj) {
         return object::make_object<relation_value_type>(join_columns.inverse_join_column, join_columns.join_column, obj, ptr_);
       });
   }
 
 private:
-  template<class EntityType>
-  static std::pair<std::type_index, const void *> make_visit_key(const EntityType &ptr) {
-    return {std::type_index(typeid(EntityType)), static_cast<const void *>(&ptr)};
+  template<class PointerType>
+  void on_foreign_object(object::object_ptr<PointerType> &obj, const utils::foreign_attributes &attr) {
+    if (!utils::is_cascade_type_set(attr.cascade(), utils::cascade_type::Insert) || !obj || obj.is_transient()) {
+      return;
+    }
+
+    insert_context ctx{ctx_.schema_, ctx_.contexts_by_type_};
+    insert_step_processor<PointerType> processor{ctx};
+
+    const auto result = processor.build(obj);
+    if (!result) {
+      throw query_builder_exception(error_code::InvalidObject, "Invalid object");
+      // return utils::failure(result.err());
+    }
   }
 
-  struct visit_key_hash {
-    size_t operator()(const std::pair<std::type_index, const void *> &p) const noexcept {
-      // combine hashes (simple + sufficient here)
-      const size_t h1 = p.first.hash_code();
-      const size_t h2 = std::hash<const void *>{}(p.second);
-      return h1 ^ (h2 + 0x9e3779b97f4a7c15ULL + (h1 << 6) + (h1 >> 2));
-    }
-  };
-
-  template<class EntityType>
-  utils::result<void, utils::error> build_insert_steps(const object::object_ptr<EntityType> &ptr, std::vector<std::unique_ptr<insert_step>> &steps) {
-    if (!ptr) {
-      return utils::failure(utils::error{error_code::InvalidObject, "Object is null"});
-    }
-
-    const auto key = make_visit_key<EntityType>(*ptr);
-    if (visited_.find(key) != visited_.end()) {
-      return utils::ok<void>();
-    }
-    visited_.insert(key);
-
-    const auto it = schema_.find(typeid(EntityType));
-    if (it == schema_.end()) {
-      return utils::failure(utils::error{error_code::UnknownType, "Unknown type"});
-    }
-
-    // 1) Traverse relations first => dependencies will be inserted before this object
-    try {
-      access::process(*this, *ptr);
-    } catch (const query_builder_exception &ex) {
-      return utils::failure(ex.error());
-    }
-
-    // 2) Build INSERT for this object
-    const auto &info = it->second.node().info();
-    if (!info.has_primary_key() || it->second.pk_generator().type() == utils::generator_type::None) {
-      return utils::failure(utils::error{error_code::MissingPrimaryKey, "Type " + info.name() + " has no primary key"});
-    }
-    const auto cit = contexts_by_type_.find(it->second.node().info().type_index());
-    if (cit == contexts_by_type_.end()) {
-      return utils::failure(utils::error{error_code::UnknownType, "Unknown type"});
-    }
-
-    if (it->second.pk_generator().type() == utils::generator_type::Manual) {
-      steps.push_back(std::make_unique<insert_step_pk_manual<EntityType>>(cit->second.insert, ptr));
-    } else if (it->second.pk_generator().type() == utils::generator_type::Identity) {
-      steps.push_back(std::make_unique<insert_step_pk_identity<EntityType>>(cit->second.insert, ptr, info.primary_key_attribute()->name()));
-    } else {
-      steps.push_back(std::make_unique<insert_step_pk_generated<EntityType>>(cit->second.insert, ptr, it->second.pk_generator()));
-    }
-
-    return utils::ok<void>();
-  }
-
-  template<class LocalType, class ForeignType, class RelationFactory>
-  void insert_many_to_many_relations(const char *id,
-                                     object::collection<object::object_ptr<ForeignType>> &objects,
-                                     const utils::foreign_attributes &attr,
-                                     RelationFactory make_relation) {
+    template<class LocalType, class ForeignType, class RelationKeyFactory, class RelationFactory>
+    void insert_many_to_many_relations(const char *id,
+                                       object::collection<object::object_ptr<ForeignType>> &objects,
+                                       const utils::foreign_attributes &attr,
+                                       RelationKeyFactory make_relation_key,
+                                       RelationFactory make_relation) {
     if (!utils::is_cascade_type_set(attr.cascade(), utils::cascade_type::Insert)) {
       return;
     }
 
-    if (processing_many_to_many_relations_.find(id) != processing_many_to_many_relations_.end()) {
+    const auto key = make_relation_key(id);
+    if (ctx_.processing_many_to_many_relations_.find(key) != ctx_.processing_many_to_many_relations_.end()) {
       return;
     }
 
-    const auto it = schema_.find(std::string{id});
-    if (it == schema_.end()) {
+    const auto it = ctx_.schema_.find(std::string{id});
+    if (it == ctx_.schema_.end()) {
       throw query_builder_exception(error_code::UnknownType, "Unknown type");
     }
 
@@ -284,24 +347,23 @@ private:
       throw query_builder_exception(error_code::InvalidRelationType, "Invalid relation type");
     }
 
-    const auto cit = contexts_by_type_.find(it->second.node().info().type_index());
-    if (cit == contexts_by_type_.end()) {
+    const auto cit = ctx_.contexts_by_type_.find(it->second.node().info().type_index());
+    if (cit == ctx_.contexts_by_type_.end()) {
       throw query_builder_exception(error_code::UnknownType, "Unknown type");
     }
 
-    std::ignore = processing_many_to_many_relations_.insert(id);
+    std::ignore = ctx_.processing_many_to_many_relations_.insert(key);
     std::vector<std::unique_ptr<insert_step>> insert_relation_steps;
+    insert_step_processor<ForeignType> processor(ctx_);
     for (auto &obj : objects) {
-      if (!obj) {
+      if (!obj || !obj.is_transient()) {
         continue;
       }
 
-      // Ensure target exists as dependency (deps first)
-      if (obj.is_transient()) {
-        const auto result = build_insert_steps(obj, relation_steps_);
-        if (!result) {
-          throw query_builder_exception(error_code::InvalidObject, "Invalid object");
-        }
+      const auto result = processor.build(obj);
+      if (!result) {
+        throw query_builder_exception(error_code::InvalidObject, "Invalid object");
+        // return utils::failure(result.err());
       }
 
       auto rel = make_relation(obj);
@@ -310,43 +372,43 @@ private:
 
       insert_relation_steps.push_back(std::make_unique<insert_step_relation<LocalType>>(cit->second.insert, rel));
     }
-    relation_steps_.insert(
-      relation_steps_.end(),
+    ctx_.relation_steps_.insert(
+      ctx_.relation_steps_.end(),
       std::make_move_iterator(insert_relation_steps.begin()),
       std::make_move_iterator(insert_relation_steps.end()));
-    processing_many_to_many_relations_.erase(id);
-  }
-  template<class Pointer>
-  void on_foreign_object(Pointer &obj, const utils::foreign_attributes &attr) {
-    if (!utils::is_cascade_type_set(attr.cascade(), utils::cascade_type::Insert)) {
-      return;
-    }
-
-    if (!obj) {
-      return;
-    }
-
-    if (obj.is_persistent()) {
-      return;
-    }
-
-    using dep_t = std::remove_reference_t<decltype(*obj)>;
-    const auto result = build_insert_steps<dep_t>(obj, steps_);
-    if (!result) {
-      throw query_builder_exception(error_code::InvalidObject, "Invalid object");
-    }
+    ctx_.processing_many_to_many_relations_.erase(key);
   }
 
 private:
-  const basic_schema &schema_;
-  const std::unordered_map<std::type_index, query_contexts> &contexts_by_type_;
-
+  insert_context& ctx_;
   object::object_ptr<ObjectType> ptr_;
+};
 
-  std::vector<std::unique_ptr<insert_step>> steps_;
-  std::vector<std::unique_ptr<insert_step>> relation_steps_;
-  std::unordered_set<std::pair<std::type_index, const void *>, visit_key_hash> visited_;
-  std::unordered_set<std::string> processing_many_to_many_relations_;
+template<class ObjectType>
+class insert_query_builder {
+public:
+  explicit insert_query_builder(const basic_schema &schema, const std::unordered_map<std::type_index, query_contexts> &contexts_by_type)
+  : context_{schema, contexts_by_type}
+  {}
+
+  utils::result<std::vector<std::unique_ptr<insert_step>>, utils::error> build(const object::object_ptr<ObjectType> &ptr) {
+    if (const auto it = context_.schema_.find(typeid(ObjectType)); it == context_.schema_.end()) {
+      return utils::failure(utils::error{error_code::UnknownType, "Unknown type for insert query"});
+    }
+
+    insert_context ctx{context_.schema_, context_.contexts_by_type_};
+    insert_step_processor<ObjectType> processor{ctx};
+
+    const auto result = processor.build(ptr);
+    if (!result) {
+      return utils::failure(result.err());
+    }
+
+    return utils::ok(std::move(ctx.steps_));
+  }
+
+private:
+  insert_context context_;
 };
 }
 #endif //MATADOR_INSERT_QUERY_BUILDER_HPP
\ No newline at end of file