Uber engineers say they changed how code is merged after AI-written changes overwhelmed its existing process. They report that allowing more parallel builds brought peak throughput to almost 250 and sometimes 300 merges an hour, but introduced new testing risks.
Uber engineers told AI Engineer about changes to its SubmitQueue system. They said the revised approach restored P95 land time to 30 minutes, meaning 95% of code changes were merged within that time.
Staff engineer Preetam Dwivedi said requests rose from 90 an hour in January 2026 to 130 by March, linking the increase to AI-written code changes. He said P95 land time had stretched from 30 minutes to 3 to 4 hours, even while the main code branch remained healthy.
Senior engineer Manjari Akella said admission controls separate small changes from expensive ones, deferring expensive work during busy periods and replaying it when capacity becomes available. She said the larger gain came from relaxing conflict checks between weakly overlapping changes so more builds could run in parallel.
Akella said that approach can let untested combinations reach the main branch and break it. She said Uber uses StowPipe to validate changes after merging and keep a reference to the last verified version of the main branch until builds pass. Uber's experience suggests that faster AI coding can shift pressure onto integration, with additional safeguards needed to manage that trade-off.
Uber's experience suggests that more AI-written code can move the engineering bottleneck from writing changes to testing and merging them.
Uber's engineers report throughput gains from implemented changes to integration infrastructure, rather than merely announcing a planned update.
Uber's use of post-merge validation and a verified reference point illustrates safeguards builders may need when relaxing pre-merge checks.
Written automatically by the Made in 10 Newsroom from the source above.
Claude Code missed about $800,000 in contract value and gave the wrong renewal deadline in a procurement test. An unlinked amendment explained the missing value, despite correct annual spending totals and plausible-looking tables.
