diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index fd9a63c2b..74af19e6e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -40,10 +40,6 @@ jobs:
       env:
         COVERAGE_FILE: ".coverage.${{ matrix.python-version }}"
         PYTEST_ARGS: "--cov=karapace --cov-append"
-    - run: make integration-tests
-      env:
-        COVERAGE_FILE: ".coverage.${{ matrix.python-version }}"
-        PYTEST_ARGS: "--cov=karapace --cov-append --random-order"
 
     - name: Archive logs
       uses: actions/upload-artifact@v4
diff --git a/karapace/protobuf/io.py b/karapace/protobuf/io.py
index 3cc7445dc..7274caeca 100644
--- a/karapace/protobuf/io.py
+++ b/karapace/protobuf/io.py
@@ -13,13 +13,13 @@
 from karapace.protobuf.schema import ProtobufSchema
 from karapace.protobuf.type_element import TypeElement
 from multiprocessing import Process, Queue
+from pathlib import Path
 from typing import Dict, Final, Generator, Iterable, Protocol
 from typing_extensions import Self, TypeAlias
 
 import hashlib
 import importlib
 import importlib.util
-import os
 import subprocess
 import sys
 
@@ -96,7 +96,7 @@ def get_protobuf_class_instance(
     class_name: str,
     cfg: Config,
 ) -> _ProtobufModel:
-    directory = cfg["protobuf_runtime_directory"]
+    directory = Path(cfg["protobuf_runtime_directory"])
     deps_list = crawl_dependencies(schema)
     root_class_name = ""
     for value in deps_list.values():
@@ -104,21 +104,19 @@ def get_protobuf_class_instance(
     root_class_name = root_class_name + str(schema)
     proto_name = calculate_class_name(root_class_name)
 
-    proto_path = f"{proto_name}.proto"
-    work_dir = f"{directory}/{proto_name}"
-    if not os.path.isdir(directory):
-        os.mkdir(directory)
-    if not os.path.isdir(work_dir):
-        os.mkdir(work_dir)
-    class_path = f"{directory}/{proto_name}/{proto_name}_pb2.py"
-    if not os.path.exists(class_path):
+    main_proto_filename = f"{proto_name}.proto"
+    work_dir = directory / Path(proto_name)
+    work_dir.mkdir(exist_ok=True, parents=True)
+    class_path = work_dir / Path(f"{proto_name}_pb2.py")
+
+    if not class_path.exists():
         with open(f"{directory}/{proto_name}/{proto_name}.proto", mode="w", encoding="utf8") as proto_text:
             proto_text.write(replace_imports(str(schema), deps_list))
 
         protoc_arguments = [
             "protoc",
             "--python_out=./",
-            proto_path,
+            main_proto_filename,
         ]
         for value in deps_list.values():
             proto_file_name = value["unique_class_name"] + ".proto"
@@ -127,16 +125,18 @@ def get_protobuf_class_instance(
             with open(dependency_path, mode="w", encoding="utf8") as proto_text:
                 proto_text.write(replace_imports(value["schema"], deps_list))
 
-        if not os.path.isfile(class_path):
+        if not class_path.is_file():
             subprocess.run(
                 protoc_arguments,
                 check=True,
                 cwd=work_dir,
             )
 
-    # todo: This will leave residues on sys.path in case of exceptions. If really must
-    #  mutate sys.path, we should at least wrap in try-finally.
-    sys.path.append(f"./runtime/{proto_name}")
+    runtime_proto_path = f"./runtime/{proto_name}"
+    if runtime_proto_path not in sys.path:
+        # todo: This will leave residues on sys.path in case of exceptions. If really must
+        # mutate sys.path, we should at least wrap in try-finally.
+        sys.path.append(runtime_proto_path)
     spec = importlib.util.spec_from_file_location(f"{proto_name}_pb2", class_path)
     # This is reasonable to assert because we just created this file.
     assert spec is not None
@@ -240,7 +240,7 @@ def read(self, bio: BytesIO) -> dict:
         return read_in_forked_process_multiprocess_process(self.config, self._writer_schema, self._reader_schema, bio)
 
 
-_WriterQueue: TypeAlias = "Queue[bytes | BaseException]"
+_WriterQueue: TypeAlias = "Queue[bytes | str | BaseException]"
 
 
 def writer_process(
@@ -253,6 +253,8 @@ def writer_process(
     try:
         class_instance = get_protobuf_class_instance(writer_schema, message_name, config)
         dict_to_protobuf(class_instance, datum)
+        result = class_instance.SerializeToString()
+        writer_queue.put(result)
     # Writing happens in the forked process, catch is broad so exception will get communicated
     # back to calling process.
     except Exception as bare_exception:  # pylint: disable=broad-exception-caught
@@ -263,7 +265,6 @@ def writer_process(
             raise protobuf_exception
     except BaseException as base_exception:  # pylint: disable=broad-exception-caught
         writer_queue.put(base_exception)
-    writer_queue.put(class_instance.SerializeToString())
 
 
 def write_in_forked_process(