A system and method for isolating one or more code changes which are suspected of causing a code failure are disclosed. An example system may include a backend, a frontend, and a datastore. A list of changes to a codebase may be received along with a list of test targets in the codebase that are failing and a snapshot of the codebase at the time when one or more of the codebase's tests started failing. A heuristic may be used to find the code changes causing the one or more code failures.