Four services. One afternoon.
Zero context switching.
You need to migrate four services to a new auth middleware before Friday. Same change in each repo, slightly different shape. Here's the workflow.
Sequential refactors eat days. You finish services/auth, switch branches, lose the mental model, and start over on services/billing. By the third repo you're copy-pasting patterns by hand and forgetting which test suite has already been updated. The change is the same. The repetition is the cost.
Five steps. One pass.
Spawn four worktrees.
Open Nest, hit ⌘N four times. Each pane spawns a fresh worktree from main (services/auth, services/billing, services/notifications and services/api), each with its own deps and dev server port.
❯ git worktree add ../auth-migration/auth feat/auth-middleware ❯ git worktree add ../auth-migration/billing feat/auth-middleware ❯ git worktree add ../auth-migration/notifications feat/auth-middleware ❯ git worktree add ../auth-migration/api feat/auth-middleware Preparing worktree (new branch 'feat/auth-middleware') HEAD is now at 4f1c2a8 chore: bump deps ✓ 4 worktrees ready · isolated ports 5173–5176
Assign an agent per pane.
Claude on auth, Claude on billing, Gemini on notifications, Codex on api. Each pane has its own HOME directory. No credential collisions, even with two Claude accounts running side by side.
Broadcast the prompt once.
Save the migration prompt as a snippet. ⌘B to broadcast across the four panes. Same instructions, four contexts, sent in one keystroke.
Migrate this service to the new auth middleware. 1. Replace verifyJwt() with withAuth() from @org/auth-v2. 2. Update routes that import the old helper. 3. Add coverage for the 401 path. 4. Run tests and report.
Babysit, not type.
Each pane runs its agent in parallel. You skim outputs, accept patches, run tests per worktree. The dev servers run on isolated ports. No collisions, no rebuilds, no waiting.
Four PRs, one review pass.
From each pane: pr open. Nest opens four PRs against main. You review them with the same context already loaded. No rehydration, no re-reading the diff three days later. Merge in order.
Migration done in one focused afternoon. No branch juggling. No copying patterns by hand.
The work that used to be a sprint is now a workflow.
Stop juggling tabs.
Start shipping.
Free during launch. No credit card. Works with the tools you already have, and the ones you didn't know you needed.