Technology Radar
Unattended overnight agentic builds refers to the practice of giving a coding agent a feature-sized piece of work when the team leaves for the evening and reviewing what it produced the next morning. We've done this with epic-level features and infrastructure tasks that can take hours. One agent is enough, without a coding agent swarm, although it may use subagents. One Thoughtworks team spends the day collaborating on plans and specifications and leaves the coding to agents overnight. "Overnight" is in the name because it's hard to fake. A team that can do this will likely run similar jobs during the day too. (A team that doesn't leave an agent coding unwatched overnight probably isn't running fully autonomous work during the day either.)
Like microservice prerequisites, this practice has entry requirements, and pushing teams to meet them is a big part of its value. Agents need sandboxed execution, work specified up front as in spec-driven development and feedback sensors so they can correct their own mistakes. A night's work can be too large a batch to review effectively line by line, so teams need a harness they've tested to validate the changes instead of relying on human code review. Complementary techniques include running the agent in a managed agents runtime and letting agents keep the build green by fixing pipeline failures themselves. We've placed this in Trial for teams that have those foundations; for other teams, it's a goal that justifies building them.
