While I agree that the name Dependency Injection is so well known that most likely even non-english speaking programmers are likely to be familiar with it and the feature itself is a key feature of FastAPI, I still think that the term Wstrzykiwanie Zależności should be used here. It's well established in polish literature.

I would suggest going with:

Wstrzykiwanie Zależności (Dependency Injection)

or the other way around:

Dependency Injection (Wstrzykiwanie Zależności)

I was thinking about it for a while, but then I noticed that in some other language versions of documentation it's translated, and in others it's not.
So I've decided to go with the same pattern as in spanish translation, which is using "Dependency Injection" as a header but in the next line is adding title for another occurrence, but with explaination in spanish:

My reasoning for it was that "Dependency Injection" is definitely used more often in web development industry than "Wstrzykiwanie Zależności", but anyway, to not leaving it untranslated, I've provided translation for it in the next line.

But I agree with you, I'll go with just "Wstrzykiwanie Zależności" as a header, and english version of it in a tooltip (like on the screenshot, but "reversed").

Let me know if that will be fine.

Yes, I guess that makes sense.

weryfikować i adnotować

once more you used 'weryfikować' instead of 'walidować' which would be more consistent with the rest of your translation.
'Walidacja' is an actual word in polish, though I agree that using it as a verb (walidować) is not something you see often.

Maybe this should be: 'poddać walidacji'
This way it could be both correct and more pleasant to look at. 🤔

Yes, I agree that "poddać walidacji" sounds much better, thanks!