The Pragmatic Programmer

I re-read this whenever I feel my engineering habits getting sloppy. What holds up isn't the specific advice — it's the posture: treat your work as a craft, take responsibility, and stay curious about your tools.

"Don't repeat yourself" and "tracer bullets" are the famous ideas, but the quieter theme is care. The authors clearly love the work, and that love is contagious. If you write software for a living, this belongs on the shelf you actually revisit.