AI coding has made CI a bottleneck, so we reworked ours to keep up

Linear's account of rebuilding its automated checks separates two costs of faster coding: how long a change waits for validation and how much computing time validation consumes. The company reports reducing pull-request wait time from more than six minutes to just over five while roughly halving machine time per test, even as its test suites nearly quadrupled.

One improvement targeted repeated preparation. Seven short checks each started a machine, checked out code and installed dependencies. Combining them into two jobs kept the seven checks running concurrently while paying that setup cost twice. Linear estimates this saved about 87,000 minutes of machine time per month based on June usage. The example shows how reorganizing validation work can recover capacity without removing the checks.