Guides

Step-by-step fixes for the problems people search for most, each with a terminal you can watch.

1 min

Fix “port already in use” (EADDRINUSE)

Your dev server won’t start because something is already on port 3000? Find it and stop it in under a minute.

Start guide3 min

Undo a Git commit (the safe way)

Which undo you need depends on whether you’ve pushed. Here’s how to pick the right one without losing work.

Start guide4 min

Set up an SSH key for GitHub

Push and pull without typing a password. Generate a key, add it to GitHub, and test it.

Start guide5 min

Free up disk space on a Mac (developer edition)

Caches, old dependencies and Docker images quietly eat tens of gigabytes. Find them and clean them safely.

Start guide10 min

Set up a new Mac for development

From a fresh Mac to a ready-to-code machine: tools, Homebrew, Git identity, SSH and sensible Finder settings.

Start guide2 min

Why commands copied from websites break

“Unknown option –save”? “Invalid character”? Blogs and AI chats quietly corrupt commands. Here’s what happens and how to fix it.

Start guide3 min

Start a Python project the right way

Isolated environments, pinned dependencies and fast installs with venv or uv.

Start guide2 min

Reclaim disk space from Docker

Docker can silently use 20+ GB. Measure, then clean in order from safest to most aggressive.

Start guide