Uber saves about 21,000 developer hours generating tests on LangGraph
Uber built AutoCover, a multi-agent test generator wrapping LangGraph in an internal framework, and reports roughly 21,000 developer hours saved across about 5,000 engineers.
Uber's platform team built AutoCover, a multi-agent system that scaffolds a test environment, identifies business cases, writes tests and runs coverage analysis, parallelising up to 100 generation iterations on large source files. It wraps LangGraph and LangChain in an internal framework the team calls Lang Effect so the agents integrate with existing infrastructure. The published outcome is roughly 21,000 developer hours saved across about 5,000 engineers. The stack signal is notable: even at Uber's scale the choice was to wrap an open orchestration framework rather than adopt a closed platform, because the team needed explicit control over state, loops and retries. For an engineering-led organisation, this is the build-your-own path.