Using PowerShell to launch multiple npm/yarn scripts in a multi-pane Windows Terminal

I have a monorepo with multiple TypeScript projects, each with its own dev server or file watcher.

Manually opening multiple terminals and starting each dev server became repetitive, so I looked for a way to automate it.

My solution uses Windows Terminal's split pane feature, similar to tmux. Windows Terminal provides a CLI interface to launch a terminal, split it into multiple panes, and run a command in each one.

I wrote this PowerShell script as a shortcut:

$WtArgs = (
  "new-tab -d . pwsh -NoProfile -NoExit -Command yarn workspace @foxandfly/package-1 run start ; ",
  "split-pane -d . pwsh -NoProfile -NoExit -Command yarn workspace @foxandfly/package-2 run start ; ",
  "split-pane -d . pwsh -NoProfile -NoExit -Command yarn workspace @foxandfly/package-3 run start "
)

Start-Process wt $WtArgs

So now, whenever I want to start all my dev servers, I just run dev.ps1 from the root of my monorepo.