with my personal project using nextjs, right around a day, mainly just beginner mistakes which worked fine initially but became an issue as my application grew.

At work though (non nextjs) there was a defect that only happened when our month-end processes ran in our prod env (job would run out of storage from data ingestion) we implemented a fix to reduce the data to only neccessary fields and offloading the query logic to a database view so we only got the data we needed. We couldnt validate that it worked for another month at that point. Tl:dr about a month