Background Agents and Asynchronous Delegation

Synchronous agent use — you watch the agent work — caps your leverage at one attention-stream. Asynchronous delegation removes the cap: hand an agent an issue-sized task, walk away, and get back a pull request. The category matured through 2025–2026 into a standard part of professional workflows, and it is still shipping fast enough that any tool matrix goes stale in months (this one is dated August 2026).

The Platforms

Mechanically these are ParallelAgentsAndWorktrees with the isolation moved server-side: each delegated task gets a sandboxed checkout and branch, and the PR is the merge discipline. Long-running platforms add checkpointing and resume, with sessions ranging from minutes to days.

What Delegates Well

Async delegation works when the task is well-specified, bounded, and mechanically verifiable — the agent cannot ask you mid-flight follow-ups, so ambiguity that a synchronous session would resolve in one exchange becomes a wrong PR:

What delegates poorly: open design questions, anything requiring taste or product judgment, tasks whose acceptance criteria you can't write down, and work in code you don't yet understand yourself — reviewing a PR in unfamiliar territory costs more than pairing synchronously would have.

A reliable task template: context (links, constraints, relevant files), acceptance criteria (checkable), verification command (the exact command whose green output means done). If you can't fill in the third field, the task isn't ready for async.

The Economics: Your Review Queue Is the Bottleneck

The naive read is "agents work while I sleep, so throughput is free." The actual constraint is that every delegated task returns as a PR you must review, and review of unfamiliar diffs is expensive. Async delegation pays when:

  1. Tasks are chosen so the verification is cheap (mechanical checks, good tests) even when the diff is large.
  2. A review agent runs as first pass on every returned PR (VerificationLoopsForAgenticCoding), so human review starts from findings, not from scratch.
  3. You dispatch in batches and review in batches, rather than context-switching per PR — the dispatcher-and-review-queue rhythm that defines Level 4 of the AgenticCodingMaturityModel.

Babysitting — watching an async agent work — is the anti-pattern that deletes the entire benefit. If a task needs watching, it wasn't an async task.

Safety and Sandboxing

See Also