Add subsetion for structure

README.md

@@ -964,6 +964,64 @@ def some_service_name(*args, **kwargs):
 
 This is a task, having the same name as a service, which holds the actual business logic.
 
+### Structure
+
+#### Configuration
+
+We put Celery confguration in a Django app called `tasks`. The [Celery config](https://docs.celeryproject.org/en/latest/django/first-steps-with-django.html) itself is located in `apps.py`, in `TasksConfig.ready` method.
+
+This Django app also holds any additional utilities, related to Celery.
+
+Here's an example `project/tasks/apps.py` file:
+
+```python
+import os
+from celery import Celery
+from django.apps import apps, AppConfig
+from django.conf import settings
+
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'config.settings.local')
+
+
+app = Celery('project')
+
+
+class TasksConfig(AppConfig):
+    name = 'project.tasks'
+    verbose_name = 'Celery Config'
+
+    def ready(self):
+        app.config_from_object('django.conf:settings', namespace="CELERY")
+        app.autodiscover_tasks()
+
+
+@app.task(bind=True)
+def debug_task(self):
+    from celery.utils.log import base_logger
+    base_logger = base_logger
+
+    base_logger.debug('debug message')
+    base_logger.info('info message')
+    base_logger.warning('warning message')
+    base_logger.error('error message')
+    base_logger.critical('critical message')
+
+    print('Request: {0!r}'.format(self.request))
+
+    return 42
+```
+
+#### Tasks
+
+Tasks are located in in `tasks.py` modules in different apps.
+
+We follow the same rules as with everything else (APIs, services, selectors): **if the tasks for a given app grow too big, split them by domain.**
+
+Meaning, you can end up with `tasks/domain_a.py` and `tasks/domain_b.py`. All you need to do is impor them in `tasks/__init__.py` for Celery to autodiscover them.
+
+The general rule of thumb is - split your tasks in a way that'll make sense to you.
+
 ## Inspiration
 
 The way we do Django is inspired by the following things: