Port Monitor

Purpose

Ports get clogged with zombie processes from ad hoc projects all the time — a Next.js dev server on 3000, a Go API on 8080, a Python server on 5000, none of them properly killed. Port Monitor shows what is running on which port and lets you kill it. Simple problem, simple solution.

Stack

What I Learned

• The command lsof -i :3000 shows which process is using port 3000. kill -9 <PID> terminates it. Port Monitor wraps this into a friendlier interface. The underlying OS tools are powerful but not discoverable — most developers google "how to kill process on port" multiple times per year. Wrapping the commands into a tool eliminates the search.
• Zombie processes on ports are a symptom of poor shutdown hygiene — Ctrl+C sometimes does not send SIGTERM cleanly, background processes outlive the terminal that started them, and Docker containers hold ports even after the container stops. Port Monitor is the cleanup crew for the mess that rapid development creates.
• Developer tools that solve annoyances you face daily are the highest-value, lowest-effort tools you can build. Port Monitor, Video Speed Controller, Chrome Save Tabs — all tiny, all daily-use, all disproportionately useful relative to their size.

Key Insights

• The best developer tools are the ones that feel embarrassingly simple. "Show me what is on this port and let me kill it" is not a complex product. But the fact that every developer has googled it proves the friction is real. Simple tools for real friction beat complex tools for imagined problems every time.