[dusted]

Sounds like a shitty company if they just straight out fire you because of that. They should have worked with you first, tried to identify the reason for this mismatch of expectations.

Speed depends on external factors too, did you have the resources available to succeed ? Was the problem well defined and well understood by you ? Were someone available to ask if you needed additional information? Were your manager following up on your issues? Did requirements change, was this expected and understood? Were your expectations aligned with regards to prioritizing production speed versus quality versus documentation?