diff --git a/config.yaml b/config.yaml
index 3cd4291..592d0e2 100755
--- a/config.yaml
+++ b/config.yaml
@@ -4,9 +4,12 @@ service:
   response_formatter: default  # formats analysis payloads of response messages
   upload_formatter: projecting  # formats analysis payloads of objects uploaded to storage
   # Note: This is not really the right place for this. It should be configured on a per-service basis.
+  operation: $OPERATION|default
+  # operation needs to be specified in deployment config for services that are called without an operation specified
   operations:
     conversion:
       input:
+        multi: False
         subdir: ""
         extension: ORIGIN.pdf.gz
       output:
@@ -14,6 +17,7 @@ service:
         extension: json.gz
     extraction:
       input:
+        multi: False
         subdir: ""
         extension: ORIGIN.pdf.gz
       output:
@@ -21,15 +25,25 @@ service:
         extension: json.gz
     table_parsing:
       input:
+        multi: True
         subdir: "pages_as_images"
         extension: json.gz
       output:
         subdir: "table_parses"
         extension: json.gz
+    image_classification:
+      input:
+        multi: True
+        subdir: "extracted_images"
+        extension: json.gz
+      output:
+        subdir: ""
+        extension: IMAGE_INFO.json.gz
     default:
       input:
+        multi: False
         subdir: ""
-        extension: IN.gz
+        extension: in.gz
       output:
         subdir: ""
         extension: out.gz
diff --git a/pyinfra/component_factory.py b/pyinfra/component_factory.py
index 564c554..80d9069 100644
--- a/pyinfra/component_factory.py
+++ b/pyinfra/component_factory.py
@@ -5,6 +5,7 @@ from funcy import project, identity, rcompose
 
 from pyinfra.callback import Callback
 from pyinfra.config import parse_disjunction_string
+from pyinfra.file_descriptor_builder import RedFileDescriptorBuilder
 from pyinfra.file_descriptor_manager import FileDescriptorManager
 from pyinfra.pipeline_factory import CachedPipelineFactory
 from pyinfra.queue.consumer import Consumer
@@ -84,13 +85,20 @@ class ComponentFactory:
     def get_file_descriptor_manager(self):
         return FileDescriptorManager(
             bucket_name=parse_disjunction_string(self.config.storage.bucket),
-            operation2file_patterns=self.get_operation2file_patterns(),
+            file_descriptor_builder=self.get_operation_file_descriptor_builder(),
         )
 
     @lru_cache(maxsize=None)
     def get_upload_formatter(self):
         return {"identity": identity, "projecting": ProjectingUploadFormatter()}[self.config.service.upload_formatter]
 
+    @lru_cache(maxsize=None)
+    def get_operation_file_descriptor_builder(self):
+        return RedFileDescriptorBuilder(
+            operation2file_patterns=self.get_operation2file_patterns(),
+            default_operation_name=self.config.service.operation,
+        )
+
     @lru_cache(maxsize=None)
     def get_response_formatter(self):
         return {"default": DefaultResponseFormatter(), "identity": IdentityResponseFormatter()}[
@@ -99,6 +107,8 @@ class ComponentFactory:
 
     @lru_cache(maxsize=None)
     def get_operation2file_patterns(self):
+        if self.config.service.operation is not "default":
+            self.config.service.operations["default"] = self.config.service.operations[self.config.service.operation]
         return self.config.service.operations
 
     @lru_cache(maxsize=None)
diff --git a/pyinfra/file_descriptor_builder.py b/pyinfra/file_descriptor_builder.py
new file mode 100644
index 0000000..0dec1e9
--- /dev/null
+++ b/pyinfra/file_descriptor_builder.py
@@ -0,0 +1,99 @@
+import abc
+import os
+from operator import itemgetter
+
+from funcy import project
+
+
+class FileDescriptorBuilder:
+    @abc.abstractmethod
+    def build_file_descriptor(self, queue_item_body, end="input"):
+        raise NotImplementedError
+
+    @abc.abstractmethod
+    def build_matcher(self, file_descriptor):
+        raise NotImplementedError
+
+    @staticmethod
+    @abc.abstractmethod
+    def build_storage_upload_info(analysis_payload, request_metadata):
+        raise NotImplementedError
+
+    @abc.abstractmethod
+    def get_path_prefix(self, queue_item_body):
+        raise NotImplementedError
+
+
+class RedFileDescriptorBuilder(FileDescriptorBuilder):
+    """Defines concrete descriptors for storage objects based on queue messages"""
+
+    def __init__(self, operation2file_patterns, default_operation_name):
+
+        self.operation2file_patterns = operation2file_patterns or self.get_default_operation2file_patterns()
+        self.default_operation_name = default_operation_name
+
+    @staticmethod
+    def get_default_operation2file_patterns():
+        return {"default": {"input": {"subdir": "", "extension": ".in"}, "output": {"subdir": "", "extension": ".out"}}}
+
+    def build_file_descriptor(self, queue_item_body, end="input"):
+
+        def pages():
+            if end == "input":
+                if "id" in queue_item_body:
+                    return [queue_item_body["id"]]
+                else:
+                    return queue_item_body["pages"] if file_pattern["multi"] else []
+            elif end == "output":
+                return [queue_item_body["id"]]
+            else:
+                raise ValueError(f"Invalid argument: {end=}")  # TODO: use an enum for `end`
+
+        operation = queue_item_body.get("operation", self.default_operation_name)
+
+        file_pattern = self.operation2file_patterns[operation][end]
+
+        file_descriptor = {
+            **project(queue_item_body, ["dossierId", "fileId", "pages"]),
+            "pages": pages(),
+            "extension": file_pattern["extension"],
+            "subdir": file_pattern["subdir"],
+        }
+
+        return file_descriptor
+
+    def build_matcher(self, file_descriptor):
+        def make_filename(file_id, subdir, suffix):
+            return os.path.join(file_id, subdir, suffix) if subdir else f"{file_id}.{suffix}"
+
+        dossier_id, file_id, subdir, pages, extension = itemgetter(
+            "dossierId", "fileId", "subdir", "pages", "extension"
+        )(file_descriptor)
+
+        matcher = os.path.join(
+            dossier_id, make_filename(file_id, subdir, self.__build_page_regex(pages, subdir) + extension)
+        )
+
+        return matcher
+
+    @staticmethod
+    def __build_page_regex(pages, subdir):
+
+        n_pages = len(pages)
+        if n_pages > 1:
+            page_re = "id:(" + "|".join(map(str, pages)) + ")."
+        elif n_pages == 1:
+            page_re = f"id:{pages[0]}."
+        else:  # no pages specified -> either all pages or no pages, depending on whether a subdir is specified
+            page_re = r"id:\d+." if subdir else ""
+
+        return page_re
+
+    @staticmethod
+    def build_storage_upload_info(analysis_payload, request_metadata):
+        storage_upload_info = {**request_metadata, "id": analysis_payload["metadata"].get("id", 0)}
+        return storage_upload_info
+
+    def get_path_prefix(self, queue_item_body):
+        prefix = "/".join(itemgetter("dossierId", "fileId")(self.build_file_descriptor(queue_item_body, end="input")))
+        return prefix
diff --git a/pyinfra/file_descriptor_manager.py b/pyinfra/file_descriptor_manager.py
index 1ca8292..13e715d 100644
--- a/pyinfra/file_descriptor_manager.py
+++ b/pyinfra/file_descriptor_manager.py
@@ -1,17 +1,18 @@
-import os
-from _operator import itemgetter
-
-from funcy import project
+from pyinfra.file_descriptor_builder import FileDescriptorBuilder
 
 
 class FileDescriptorManager:
-    def __init__(self, bucket_name, operation2file_patterns: dict = None):
-        self.bucket_name = bucket_name
-        self.operation2file_patterns = operation2file_patterns or self.get_default_operation2file_patterns()
+    """Decorates a file descriptor builder with additional convenience functionality and this way provides a
+    comprehensive interface for all file descriptor related operations, while the concrete descriptor logic is
+    implemented in a file descriptor builder.
 
-    @staticmethod
-    def get_default_operation2file_patterns():
-        return {"default": {"input": {"subdir": "", "extension": ".in"}, "output": {"subdir": "", "extension": ".out"}}}
+    TODO: This is supposed to be fully decoupled from the concrete file descriptor builder implementation, however some
+        bad coupling is still left.
+    """
+
+    def __init__(self, bucket_name, file_descriptor_builder: FileDescriptorBuilder):
+        self.bucket_name = bucket_name
+        self.operation_file_descriptor_builder = file_descriptor_builder
 
     def get_input_object_name(self, queue_item_body: dict):
         return self.get_object_name(queue_item_body, end="input")
@@ -20,46 +21,13 @@ class FileDescriptorManager:
         return self.get_object_name(queue_item_body, end="output")
 
     def get_object_name(self, queue_item_body: dict, end):
-
         file_descriptor = self.build_file_descriptor(queue_item_body, end=end)
-        file_descriptor["pages"] = [queue_item_body.get("id", 0)]
-
         object_name = self.__build_matcher(file_descriptor)
 
         return object_name
 
-    @staticmethod
-    def __build_matcher(file_descriptor):
-        def make_filename(file_id, subdir, suffix):
-            return os.path.join(file_id, subdir, suffix) if subdir else f"{file_id}.{suffix}"
-
-        dossier_id, file_id, subdir, pages, extension = itemgetter(
-            "dossierId", "fileId", "subdir", "pages", "extension"
-        )(file_descriptor)
-
-        if len(pages) > 1 and subdir:
-            page_re = "id:(" + "|".join(map(str, pages)) + ")."
-        elif len(pages) == 1 and subdir:
-            page_re = f"id:{pages[0]}."
-        else:
-            page_re = ""
-
-        matcher = os.path.join(dossier_id, make_filename(file_id, subdir, page_re + extension))
-
-        return matcher
-
     def build_file_descriptor(self, queue_item_body, end="input"):
-        operation = queue_item_body.get("operation", "default")
-
-        file_pattern = self.operation2file_patterns[operation][end]
-
-        file_descriptor = {
-            **project(queue_item_body, ["dossierId", "fileId", "pages"]),
-            "pages": queue_item_body.get("pages", []),
-            "extension": file_pattern["extension"],
-            "subdir": file_pattern["subdir"],
-        }
-        return file_descriptor
+        return self.operation_file_descriptor_builder.build_file_descriptor(queue_item_body, end=end)
 
     def build_input_matcher(self, queue_item_body):
         return self.build_matcher(queue_item_body, end="input")
@@ -71,6 +39,9 @@ class FileDescriptorManager:
         file_descriptor = self.build_file_descriptor(queue_item_body, end=end)
         return self.__build_matcher(file_descriptor)
 
+    def __build_matcher(self, file_descriptor):
+        return self.operation_file_descriptor_builder.build_matcher(file_descriptor)
+
     def get_input_object_descriptor(self, queue_item_body):
         return self.get_object_descriptor(queue_item_body, end="input")
 
@@ -78,21 +49,15 @@ class FileDescriptorManager:
         return self.get_object_descriptor(storage_upload_info, end="output")
 
     def get_object_descriptor(self, queue_item_body, end):
+        # TODO: this is complected with the Storage class API
+        # FIXME: bad coupling
         return {
             "bucket_name": self.bucket_name,
             "object_name": self.get_object_name(queue_item_body, end=end),
         }
 
-    @staticmethod
-    def build_storage_upload_info(analysis_payload, request_metadata):
-        storage_upload_info = {**request_metadata, "id": analysis_payload["metadata"].get("id", 0)}
-        return storage_upload_info
+    def build_storage_upload_info(self, analysis_payload, request_metadata):
+        return self.operation_file_descriptor_builder.build_storage_upload_info(analysis_payload, request_metadata)
 
     def get_path_prefix(self, queue_item_body):
-
-        prefix = "/".join(
-            itemgetter("dossierId", "fileId")(
-                self.build_file_descriptor(queue_item_body, end="input"),
-            )
-        )
-        return prefix
+        return self.operation_file_descriptor_builder.get_path_prefix(queue_item_body)
diff --git a/pyinfra/server/buffering/bufferize.py b/pyinfra/server/buffering/bufferize.py
index 0b152e0..5b2b4e4 100644
--- a/pyinfra/server/buffering/bufferize.py
+++ b/pyinfra/server/buffering/bufferize.py
@@ -4,7 +4,7 @@ from collections import deque
 from funcy import repeatedly, identity
 
 from pyinfra.exceptions import NoBufferCapacity
-from pyinfra.server.dispatcher.dispatcher import Nothing
+from pyinfra.server.nothing import Nothing
 
 logger = logging.getLogger(__name__)
 
diff --git a/pyinfra/server/buffering/queue.py b/pyinfra/server/buffering/queue.py
index b7c66a4..c6bd187 100644
--- a/pyinfra/server/buffering/queue.py
+++ b/pyinfra/server/buffering/queue.py
@@ -3,7 +3,7 @@ from itertools import takewhile
 
 from funcy import repeatedly
 
-from pyinfra.server.dispatcher.dispatcher import is_not_nothing, Nothing
+from pyinfra.server.nothing import is_not_nothing, Nothing
 
 
 def stream_queue(queue):
diff --git a/pyinfra/server/buffering/stream.py b/pyinfra/server/buffering/stream.py
index 1033968..f8a4adb 100644
--- a/pyinfra/server/buffering/stream.py
+++ b/pyinfra/server/buffering/stream.py
@@ -4,7 +4,7 @@ from typing import Iterable
 from funcy import first, repeatedly, mapcat
 
 from pyinfra.server.buffering.bufferize import bufferize
-from pyinfra.server.dispatcher.dispatcher import Nothing, is_not_nothing
+from pyinfra.server.nothing import Nothing, is_not_nothing
 
 
 class FlatStreamBuffer:
diff --git a/pyinfra/server/dispatcher/dispatcher.py b/pyinfra/server/dispatcher/dispatcher.py
index 62b5fc6..aabfce1 100644
--- a/pyinfra/server/dispatcher/dispatcher.py
+++ b/pyinfra/server/dispatcher/dispatcher.py
@@ -3,13 +3,7 @@ from typing import Iterable
 
 from more_itertools import peekable
 
-
-class Nothing:
-    pass
-
-
-def is_not_nothing(x):
-    return x is not Nothing
+from pyinfra.server.nothing import Nothing
 
 
 def has_next(peekable_iter):
diff --git a/pyinfra/server/nothing.py b/pyinfra/server/nothing.py
new file mode 100644
index 0000000..6d690f8
--- /dev/null
+++ b/pyinfra/server/nothing.py
@@ -0,0 +1,6 @@
+class Nothing:
+    pass
+
+
+def is_not_nothing(x):
+    return x is not Nothing
\ No newline at end of file
diff --git a/pyinfra/server/rest.py b/pyinfra/server/rest.py
deleted file mode 100644
index 4be6374..0000000
--- a/pyinfra/server/rest.py
+++ /dev/null
@@ -1,39 +0,0 @@
-# from typing import Iterable
-#
-# from funcy import rcompose
-#
-# from pyinfra.server.dispatcher.dispatchers.rest import RestDispatcher
-# from pyinfra.server.interpreter.interpreters.identity import IdentityInterpreter
-# from pyinfra.server.interpreter.interpreters.rest_callback import RestPickupStreamer
-# from pyinfra.server.packer.packers.rest import RestPacker
-# from pyinfra.server.client_pipeline import ClientPipeline
-# from pyinfra.server.receiver.receivers.rest import RestReceiver
-#
-#
-# def process_eagerly(endpoint, data: Iterable[bytes], metadata: Iterable[dict]):
-#     """Posts `data` to `url` and aggregates responses for each element of `data`."""
-#     pipeline = get_eager_pipeline(endpoint)
-#     yield from pipeline(data, metadata)
-#
-#
-# def process_lazily(endpoint, data: Iterable[bytes], metadata: Iterable[dict]):
-#     """Posts `data` to `url` and aggregates responses for each element of `data` by querying a pickup endpoint.
-#
-#     Requires:
-#         - responses must provide return pickup_endpoint as JSON payload
-#         - responses must have status code 206 for more responses coming and 204 for the last response already sent
-#     """
-#     pipeline = get_lazy_pipeline(endpoint)
-#     yield from pipeline(data, metadata)
-#
-#
-# def get_eager_pipeline(endpoint):
-#     return ClientPipeline(*pipeline_head(endpoint), IdentityInterpreter())
-#
-#
-# def get_lazy_pipeline(endpoint):
-#     return ClientPipeline(*pipeline_head(endpoint), rcompose(RestPickupStreamer(), RestReceiver()))
-#
-#
-# def pipeline_head(url):
-#     return RestPacker(), RestDispatcher(url), RestReceiver()
diff --git a/pyinfra/server/stream/rest.py b/pyinfra/server/stream/rest.py
index 8a9f3ff..0b17266 100644
--- a/pyinfra/server/stream/rest.py
+++ b/pyinfra/server/stream/rest.py
@@ -3,10 +3,10 @@ import logging
 from flask import jsonify
 from funcy import drop
 
-from pyinfra.server.dispatcher.dispatcher import Nothing
+from pyinfra.server.nothing import Nothing
 from pyinfra.server.stream.queued_stream_function import QueuedStreamFunction
 
-logger = logging.getLogger()
+logger = logging.getLogger(__name__)
 
 
 class LazyRestProcessor:
@@ -27,10 +27,12 @@ class LazyRestProcessor:
             result = Nothing
 
         if result is Nothing:
+            logger.info("Analysis completed successfully.")
             resp = jsonify("No more items left")
             resp.status_code = 204
 
         else:
+            logger.debug("Partial analysis completed.")
             resp = jsonify(result)
             resp.status_code = 206
 
diff --git a/pyinfra/server/utils.py b/pyinfra/server/utils.py
index 57c2fa1..b98b710 100644
--- a/pyinfra/server/utils.py
+++ b/pyinfra/server/utils.py
@@ -12,4 +12,5 @@ def make_streamable_and_wrap_in_packing_logic(fn, batched):
 
 
 def make_streamable(fn, batched):
+    # FIXME: something broken with batched == True
     return compose(normalize, (identity if batched else starlift)(fn))
diff --git a/pyinfra/storage/adapters/azure.py b/pyinfra/storage/adapters/azure.py
index 074a9d6..6e6edcf 100644
--- a/pyinfra/storage/adapters/azure.py
+++ b/pyinfra/storage/adapters/azure.py
@@ -5,7 +5,7 @@ from azure.storage.blob import ContainerClient, BlobServiceClient
 
 from pyinfra.storage.adapters.adapter import StorageAdapter
 
-logger = logging.getLogger()
+logger = logging.getLogger(__name__)
 logging.getLogger("azure").setLevel(logging.WARNING)
 logging.getLogger("urllib3").setLevel(logging.WARNING)
 
diff --git a/pyinfra/storage/adapters/s3.py b/pyinfra/storage/adapters/s3.py
index a7729df..cb06c67 100644
--- a/pyinfra/storage/adapters/s3.py
+++ b/pyinfra/storage/adapters/s3.py
@@ -8,7 +8,7 @@ from minio import Minio
 from pyinfra.exceptions import DataLoadingFailure
 from pyinfra.storage.adapters.adapter import StorageAdapter
 
-logger = logging.getLogger()
+logger = logging.getLogger(__name__)
 
 
 class S3StorageAdapter(StorageAdapter):
diff --git a/pyinfra/visitor/downloader.py b/pyinfra/visitor/downloader.py
index ec5573e..f7a87dc 100644
--- a/pyinfra/visitor/downloader.py
+++ b/pyinfra/visitor/downloader.py
@@ -30,11 +30,12 @@ class Downloader:
         logger.debug(f"Filtering objects in bucket {self.bucket_name} by pattern...")
 
         names_of_relevant_objects = compose(
+            list,
             self.get_pattern_filter(queue_item_body),
             self.get_names_of_all_associated_objects,
         )(queue_item_body)
 
-        logger.debug(f"Completed filtering.")
+        logger.debug(f"Found {len(names_of_relevant_objects)} objects matching filter.")
 
         return names_of_relevant_objects
 
@@ -51,5 +52,7 @@ class Downloader:
 
     def get_pattern_filter(self, queue_item_body):
         file_pattern = self.file_descriptor_manager.build_input_matcher(queue_item_body)
+
+        logger.debug(f"Filtering pattern: {file_pattern if len(file_pattern) <= 120 else (file_pattern[:120]+'...')}")
         matches_pattern = flift(file_pattern)
         return matches_pattern
diff --git a/pyinfra/visitor/strategies/response/aggregation.py b/pyinfra/visitor/strategies/response/aggregation.py
index b8ac6a7..57557b7 100644
--- a/pyinfra/visitor/strategies/response/aggregation.py
+++ b/pyinfra/visitor/strategies/response/aggregation.py
@@ -6,7 +6,7 @@ from funcy import omit, filter, first, lpluck, identity
 from more_itertools import peekable
 
 from pyinfra.file_descriptor_manager import FileDescriptorManager
-from pyinfra.server.dispatcher.dispatcher import Nothing, is_not_nothing
+from pyinfra.server.nothing import Nothing, is_not_nothing
 from pyinfra.utils.encoding import pack_analysis_payload
 from pyinfra.visitor.strategies.response.response import ResponseStrategy
 
diff --git a/scripts/mock_client.py b/scripts/mock_client.py
index 34e007b..485cc57 100644
--- a/scripts/mock_client.py
+++ b/scripts/mock_client.py
@@ -9,7 +9,7 @@ from pyinfra.storage.storages import get_s3_storage
 
 def parse_args():
     parser = argparse.ArgumentParser()
-    parser.add_argument("--bucket_name", "-b", required=True)
+    parser.add_argument("--bucket_name", "-b")
     parser.add_argument(
         "--analysis_container",
         "-a",
@@ -51,7 +51,7 @@ def make_connection() -> pika.BlockingConnection:
 def build_message_bodies(analysis_container, bucket_name):
     def update_message(message_dict):
         if analysis_container == "detr" or analysis_container == "image":
-            message_dict.update({"targetFileExtension": "ORIGIN.pdf.gz", "responseFileExtension": "IMAGE_INFO.json.gz"})
+            message_dict.update({"pages": []})
         if analysis_container == "conversion":
             message_dict.update(
                 {
@@ -97,7 +97,9 @@ def main(args):
     declare_queue(channel, CONFIG.rabbitmq.queues.input)
     declare_queue(channel, CONFIG.rabbitmq.queues.output)
 
-    for body in build_message_bodies(args.analysis_container, args.bucket_name):
+    bucket_name = args.bucket_name or parse_disjunction_string(CONFIG.storage.bucket)
+
+    for body in build_message_bodies(args.analysis_container, bucket_name):
         channel.basic_publish("", CONFIG.rabbitmq.queues.input, body)
         print(f"Put {body} on {CONFIG.rabbitmq.queues.input}")
 
diff --git a/scripts/show_compressed_json.py b/scripts/show_compressed_json.py
index ce74729..57976dc 100644
--- a/scripts/show_compressed_json.py
+++ b/scripts/show_compressed_json.py
@@ -2,25 +2,36 @@ import argparse
 import gzip
 import json
 
-from pyinfra.server.packing import bytes_to_string
+from funcy import lmap
+
+from pyinfra.server.packing import string_to_bytes
 
 
 def parse_args():
     parser = argparse.ArgumentParser()
-    parser.add_argument("--compressed_json", "-j", required=True)
+    parser.add_argument("compressed_json_path", help="Path to compressed JSON file")
     return parser.parse_args()
 
 
+def interpret(parsed):
+    try:
+        return {**parsed, "data": str(string_to_bytes(parsed["data"]))}
+    except KeyError:
+        return parsed
+
+
 def main(fp):
     with open(fp, "rb") as f:
-        compressed_json = f.read()
+        compressed_json_path = f.read()
 
-    json_str = gzip.decompress(compressed_json)
-    json_dict = json.loads(json_str)
+    json_str = gzip.decompress(compressed_json_path)
+    parsed = json.loads(json_str)
+    parsed = [parsed] if isinstance(parsed, dict) else parsed
+    parsed = lmap(interpret, parsed)
 
-    print(json.dumps(json_dict, indent=2))
+    print(json.dumps(parsed, indent=2))
 
 
 if __name__ == "__main__":
-    fp = parse_args().compressed_json
-    main(fp)
+    args = parse_args()
+    main(args.compressed_json_path)
diff --git a/test/config.yaml b/test/config.yaml
index fc5ea30..2a14dcb 100644
--- a/test/config.yaml
+++ b/test/config.yaml
@@ -1,19 +1,53 @@
 service:
   response_formatter: identity
   operations:
-    multi_inp_op:
+    upper:
       input:
-        subdir: op_inp_files
-        extension: IN.gz
+        subdir: ""
+        extension: up_in.gz
+        multi: False
       output:
-        subdir: op_outp_files
-        extension: OUT.gz
+        subdir: ""
+        extension: up_out.gz
+    extract:
+      input:
+        subdir: ""
+        extension: extr_in.gz
+        multi: False
+      output:
+        subdir: "extractions"
+        extension: gz
+    rotate:
+      input:
+        subdir: ""
+        extension: rot_in.gz
+        multi: False
+      output:
+        subdir: ""
+        extension: rot_out.gz
+    classify:
+      input:
+        subdir: ""
+        extension: cls_in.gz
+        multi: True
+      output:
+        subdir: ""
+        extension: cls_out.gz
+    stream_pages:
+      input:
+        subdir: ""
+        extension: pgs_in.gz
+        multi: False
+      output:
+        subdir: "pages"
+        extension: pgs_out.gz
     default:
       input:
         subdir: ""
         extension: IN.gz
+        multi: False
       output:
-        subdir: op_outp_files
+        subdir: ""
         extension: OUT.gz
 
 storage:
diff --git a/test/fixtures/consumer.py b/test/fixtures/consumer.py
index d4e3220..7f95699 100644
--- a/test/fixtures/consumer.py
+++ b/test/fixtures/consumer.py
@@ -26,8 +26,8 @@ def pair_data_with_queue_message(data: Iterable[bytes]):
     def inner():
         for i, d in enumerate(data):
             body = {
-                "dossierId": "folder",
-                "fileId": f"file{i}",
+                "dossierId": "dossier_id",
+                "fileId": f"file_id_{i}",
                 "targetFileExtension": "in.gz",
                 "responseFileExtension": "out.gz",
                 "pages": [0, 2, 3],
diff --git a/test/fixtures/input.py b/test/fixtures/input.py
index 6ef1365..e924d71 100644
--- a/test/fixtures/input.py
+++ b/test/fixtures/input.py
@@ -6,8 +6,8 @@ import pytest
 from PIL import Image
 from funcy import lmap, compose, flatten, lflatten, omit, second, first, lzip, merge
 
-from pyinfra.server.dispatcher.dispatcher import Nothing
 from pyinfra.server.normalization import normalize_item
+from pyinfra.server.nothing import Nothing
 from pyinfra.server.packing import pack, unpack
 from pyinfra.utils.func import star, lift, lstarlift
 from test.utils.image import image_to_bytes
@@ -150,11 +150,11 @@ def queue_message_metadata(n_items, operation_name):
     def metadata(i):
         return merge(
             {
-                "dossierId": "folder",
-                "fileId": f"file{i}",
-                "pages": [0, 2, 3],
+                "dossierId": "dossier_id",
+                "fileId": f"file_id_{i}",
             },
             ({"operation": operation_name} if operation_name else {}),
+            ({"pages": [0, 2, 3]} if n_items > 1 else {}),
         )
 
     return lmap(metadata, range(n_items))
diff --git a/test/fixtures/server.py b/test/fixtures/server.py
index ebac679..f2b02dd 100644
--- a/test/fixtures/server.py
+++ b/test/fixtures/server.py
@@ -13,7 +13,7 @@ from PIL import Image
 from funcy import retry, project, omit
 from waitress import serve
 
-from pyinfra.server.dispatcher.dispatcher import Nothing
+from pyinfra.server.nothing import Nothing
 from pyinfra.server.server import (
     set_up_processing_server,
 )
@@ -51,8 +51,9 @@ def server(server_stream_function, buffer_size, operation_name):
 
 
 @pytest.fixture
-def operation_name(many_to_n):
-    return "multi_inp_op" if many_to_n else ""
+def operation_name(core_operation):
+    operation_name = core_operation.__name__
+    return operation_name
 
 
 @pytest.fixture
@@ -99,16 +100,19 @@ def server_side_test(request):
 
 
 @pytest.fixture
-def core_operation(item_type, one_to_many, analysis_task):
+def core_operation(many_to_n, item_type, one_to_many, analysis_task):
     def duplicate(string: bytes, metadata):
         for _ in range(2):
             yield upper(string, metadata), metadata
 
     def upper(string: bytes, metadata):
-        return string.decode().upper().encode(), metadata
+        r = string.decode().upper().encode(), metadata
+        return r
 
     def extract(string: bytes, metadata):
-        for i, c in project(dict(enumerate(string.decode())), metadata["pages"]).items():
+        for i, c in project(
+            dict(enumerate(string.decode())), metadata.get("pages", range(len(string.decode())))
+        ).items():
             metadata["id"] = i
             yield c.encode(), metadata
 
@@ -126,18 +130,34 @@ def core_operation(item_type, one_to_many, analysis_task):
             yield f"page_{i}".encode(), metadata
 
     params2op = {
-        False: {
-            "string": {False: upper},
-            "image": {False: rotate, True: classify},
-        },
         True: {
-            "string": {False: extract},
-            "pdf": {False: stream_pages},
+            True: {},
+            False: {
+                "image": {True: classify},
+            },
         },
+        False: {
+            True: {
+                "string": {False: extract},
+                "pdf": {False: stream_pages},
+            },
+            False: {
+                "string": {False: upper},
+                "image": {False: rotate},
+            },
+        },
+        # False: {
+        #     "string": {False: upper},
+        #     "image": {False: rotate, True: classify},
+        # },
+        # True: {
+        #     "string": {False: extract},
+        #     "pdf": {False: stream_pages},
+        # },
     }
 
     try:
-        return params2op[one_to_many][item_type][analysis_task]
+        return params2op[many_to_n][one_to_many][item_type][analysis_task]
     except KeyError:
         msg = f"No operation defined for [{one_to_many=}, {item_type=}, {analysis_task=}]."
         pytest.skip(msg)
diff --git a/test/integration_tests/serve_test.py b/test/integration_tests/serve_test.py
index 6ce0647..8fe1d15 100644
--- a/test/integration_tests/serve_test.py
+++ b/test/integration_tests/serve_test.py
@@ -37,7 +37,7 @@ from test.config import CONFIG as TEST_CONFIG
 @pytest.mark.parametrize(
     "n_items",
     [
-        1,
+        # 1,
         3,
     ],
 )
@@ -79,10 +79,12 @@ from test.config import CONFIG as TEST_CONFIG
     "many_to_n",
     [
         True,
-        # False,
+        False,
     ],
 )
-def test_serving(server_process, bucket_name, components, targets, data_message_pairs, n_items, many_to_n):
+def test_serving(
+    operation_name, server_process, bucket_name, components, targets, data_message_pairs, n_items, many_to_n
+):
 
     storage, queue_manager, consumer, file_descriptor_manager = components
 
@@ -146,7 +148,7 @@ def upload_data_to_folder_in_storage_and_publish_single_request_to_queue(
     pages = ref_message["pages"]
 
     for data, page in zip(map(first, data_message_pairs), pages):
-        object_descriptor = file_descriptor_manager.get_input_object_descriptor(ref_message)
+        object_descriptor = file_descriptor_manager.get_input_object_descriptor({**ref_message, "id": page})
         object_descriptor["object_name"] = build_filepath(object_descriptor, page)
 
         storage.put_object(**object_descriptor, data=compress(data))
diff --git a/test/unit_tests/queue_visitor_test.py b/test/unit_tests/queue_visitor_test.py
index 4ad298c..0fd1f01 100644
--- a/test/unit_tests/queue_visitor_test.py
+++ b/test/unit_tests/queue_visitor_test.py
@@ -9,7 +9,7 @@ from test.utils.storage import pack_for_upload
 
 @pytest.fixture()
 def body():
-    return {"dossierId": "folder", "fileId": "file"}
+    return {"dossierId": "dossier_id", "fileId": "file_id"}
 
 
 @pytest.mark.parametrize("client_name", ["mock", "azure", "s3"], scope="session")
diff --git a/test/unit_tests/server/buffer_test.py b/test/unit_tests/server/buffer_test.py
index 828308f..e420343 100644
--- a/test/unit_tests/server/buffer_test.py
+++ b/test/unit_tests/server/buffer_test.py
@@ -3,7 +3,7 @@ from funcy import compose, lmapcat, compact, flatten, identity
 
 from pyinfra.exceptions import NoBufferCapacity
 from pyinfra.server.buffering.bufferize import bufferize
-from pyinfra.server.dispatcher.dispatcher import Nothing
+from pyinfra.server.nothing import Nothing
 
 
 def test_buffer(buffer_size):
diff --git a/test/unit_tests/server/pipeline_test.py b/test/unit_tests/server/pipeline_test.py
index 50d60e6..a9a83ac 100644
--- a/test/unit_tests/server/pipeline_test.py
+++ b/test/unit_tests/server/pipeline_test.py
@@ -3,7 +3,7 @@ from funcy import rcompose, compose, project, merge
 
 from pyinfra.server.buffering.stream import FlatStreamBuffer
 from pyinfra.server.client_pipeline import ClientPipeline
-from pyinfra.server.dispatcher.dispatcher import Nothing
+from pyinfra.server.nothing import Nothing
 from pyinfra.server.dispatcher.dispatchers.queue import QueuedStreamFunctionDispatcher
 from pyinfra.server.dispatcher.dispatchers.rest import RestDispatcher
 from pyinfra.server.interpreter.interpreters.identity import IdentityInterpreter
diff --git a/test/unit_tests/server/stream_buffer_test.py b/test/unit_tests/server/stream_buffer_test.py
index 3f2fa98..ec2ef2c 100644
--- a/test/unit_tests/server/stream_buffer_test.py
+++ b/test/unit_tests/server/stream_buffer_test.py
@@ -2,7 +2,7 @@ import pytest
 from funcy import repeatedly, takewhile, notnone, lmap, lmapcat, lflatten
 
 from pyinfra.server.buffering.stream import FlatStreamBuffer, StreamBuffer
-from pyinfra.server.dispatcher.dispatcher import Nothing
+from pyinfra.server.nothing import Nothing
 from pyinfra.server.stream.queued_stream_function import QueuedStreamFunction
 from pyinfra.utils.func import lift, foreach, starlift