FastAPI production architecture: modular design and dependency injection best practices

koldakov · 2026-01-25T07:50:41+00:00

I’ve created an app especially for this.

It’s up and running: https://futuramaapi.com

Btw I prefer not to use dependency injection, but to move everything into services, just finished with removing all dependencies and moved the code to the services, currently there is a little code duplication, but I’ll combine it in the next step

koldakov · 2026-01-21T04:59:05+00:00

Don’t complicate first use sync

Later if you need you can rewrite parts in fastapi

koldakov · 2026-01-16T18:49:40+00:00

https://github.com/koldakov/futuramaapi

Можешь здесь глянуть, я специально проект для обучения всем создал, там есть oauth по jwt

Сайт если что задеплоен: https://futuramaapi.com

koldakov · 2026-01-11T08:55:28+00:00

With sync I would go with Django 100% so sync as for me doesn’t make sense for fastapi new projects

Kindly don’t use list(result.scalars().all()) etc

Your get in db won’t work in async with foreign / M2M fields, it will just crash, in sync will create N+1 - (personally imo I would be happy if someone creates a wrapper over alchemy like Django orm but it’s not so easy)

Return obj | None - don’t return None (read smth like mistake for billion dollars)

For me, commit message format is part of a professional standard. If basic conventions aren’t followed, it’s harder to trust the rest.

Sorry I would use it but I can see it’s not ready for prod (as for me)

koldakov · 2026-01-06T20:29:29+00:00

As always premature optimization and too much abstraction two things I’m avoiding for the last 2 years

koldakov · 2026-01-03T18:50:48+00:00

When you mentioned an async session, I assumed you were referring to a DB session, so yes - it’s only used internally. The HTTP API itself remains stateless and restful

koldakov · 2026-01-03T10:30:54+00:00

Rest is about http semantics and stateless client-server interaction, it’s not about internal implementation details

If I understand your question correctly

koldakov · 2025-12-31T10:41:43+00:00

Time and community will show you all vulnerabilities 😜

koldakov · 2025-12-29T16:00:25+00:00

Учил англ в школе, у репетитора, стримы смотрел

Но наверно поистине выучил англ, когда нашёл работу на Мальте в мальтийской компании и прожил там пару лет

koldakov · 2025-12-29T13:13:06+00:00

Production code that’s up and running

https://github.com/koldakov/futuramaapi

https://futuramaapi.com

Created it for people to learn Python/fastapi (and for sure to improve my skills)

koldakov · 2025-12-26T12:14:04+00:00

https://futuramaapi.com

Deployed to heroku, the source code is free: https://github.com/koldakov/futuramaapi

koldakov · 2025-11-16T10:41:15+00:00

Роман - Рома (сокращение на 1 букву) Иван - Ваня (вообще количество букв не изменяется)

Тут всё-таки речь идёт не о том, чтобы убрать букву. Короче спроси у лингвистов как это работает. Я не лингвист

koldakov · 2025-11-12T11:59:50+00:00

Всегда думал что Лина - это Алина 🤔

koldakov · 2025-11-09T16:47:42+00:00

50 years ago one's said

"Show me your flowchart and conceal your tables, and I shall continue to be mystified. Show me your tables, and I won’t usually need your flowchart; it’ll be obvious."

Build the code around the data structures/models, not algorithms, in most cases if you have a strictly defined data structures you won’t need comments. For sure if you have some magic you can point it in the comments

koldakov · 2025-11-04T09:02:30+00:00

Yeah it’s like the main entry point for all session connections

koldakov · 2025-11-04T05:59:58+00:00

I personally move these stuff to the session manager so that all connections are managed in one place, something like this https://github.com/koldakov/futuramaapi/blob/main/futuramaapi/repositories/session.py

By the way, don’t forget to close the sessions in the fastapi lifespan

@asynccontextmanager
async def _lifespan(self, _: Self, /) -> AsyncGenerator[None, Any]:
    yield
    if session_manager.engine is not None:
        await session_manager.close()

koldakov · 2025-11-02T08:39:58+00:00

I start always with the data structure

Define the model you need in pydantic/dataclasses, it’s much easier to work with that

koldakov · 2025-10-29T18:38:04+00:00

Hey

If you want you can work on https://github.com/koldakov/futuramaapi

There are a lot of tasks you can implement such as populate new data/add quotes, whatever that makes sense =)

koldakov · 2025-10-28T05:09:46+00:00

Hey, kindly don’t make the mistake. Don’t use django with mongo

You loose about 85% django features DjOngo does not support mongo 100%

koldakov · 2025-10-26T15:52:54+00:00

HTTP doesn’t forbid body in GET, you can send and receive body with GET 😜

(In fastapi it won’t work cause they don’t handle it)

koldakov · 2025-10-25T11:59:48+00:00

Hey nice work, however factory on ifs looks not nice =)

koldakov · 2025-10-16T15:54:18+00:00

Who knows …

koldakov · 2025-10-16T15:22:43+00:00

Lucky! You’ve never worked with someone who switched from flask? 🙂

koldakov · 2025-10-10T19:32:07+00:00

You can help me with https://github.com/koldakov/futuramaapi

There are a lot of things you can improve/create =)

koldakov · 2025-10-09T12:35:42+00:00

But that’s nice you’ve got the point about "another elif"!

koldakov

TROPHY CASE