Parallel Processing Patterns

If you're running bash scripts that process files, hit APIs, or crunch data, this skill covers how to do it in parallel instead of one at a time. It walks through GNU Parallel (the Swiss Army knife approach), xargs with the -P flag (quick and dirty), and pure bash job pools with background processes and wait. The examples show real patterns like collecting exit codes from parallel children, capping concurrency so you don't fork-bomb yourself, and handling shared output files without races. Honestly, GNU Parallel alone is worth learning if you've been writing slow for-loops for years. The skill includes actual working code for FIFO-based work queues and job slot management, not just theory.