Tell me about a time where you failed to deliver a project on time

In my first year, I was assigned a small internal tool feature that was supposed to ship by the end of the sprint, and I missed that date by about a week. I had underestimated how long it would take to understand one part of the existing code, and I spent too long trying to solve it on my own because I thought I was close. Once I realized I was slipping, I told my lead exactly what was blocked and we paired on a simpler approach that cut some nonessential polish from the first version. We shipped the core functionality the next week, and afterward I started breaking my work into smaller checkpoints and asking for a quick review earlier when something felt uncertain. That helped me avoid the same pattern on later tasks.

At my previous job I was responsible for a small new onboarding flow for our mobile app that was supposed to go out with a marketing push; I missed the ship date by a few days because I had misunderstood the product acceptance criteria and built it in a way that didn’t meet the design handoff. As soon as QA flagged the gap, I owned the mistake, explained to the product manager and marketing team exactly what was wrong and how long a fix would take, and we agreed to delay the public launch while I focused on the correct behavior. I pushed an interim update to a small beta group so we could collect early feedback and avoid a wider problem, then finished the full fix and verified it with a short demo to product and design. Afterward I created a short pre-release checklist and started walking features through a quick design/dev review before implementation to make sure acceptance criteria were clear. That change has helped me avoid similar misses and keeps the team aligned on what “done” actually means.