Practice
Walk me through a feature you built from start to finish. What tools and languages did you use?
Read first: a sample answer
Fictional sample answer written by JoRoute to show the shape of a strong answer. Do not copy it: replace every detail with what is true for you.
I built an expense upload feature at a small fintech in 2023. I wrote the API in Python with FastAPI and the upload form in JavaScript with React, which is the technical skill I use most. The hard part was large files, so I used chunked uploads and checked each chunk with a checksum. For example, a 40 MB receipt batch that used to time out now uploads in about 20 seconds. I owned the feature from design to release, and support tickets about uploads dropped by half in the first month.