@tante My fondest experience in software was building (over ~9 years) an ERP system with the founding principle: "We want it to work for at least 30 years" which had a lot of knock-off effects. We were allowed to improve things that mattered more for maintenance than functionality.

The joy of being able to shift technology on the frontend with little effect to the backend, having response times in single digit ms and so on.

There was plenty to improve, still, but I had pride in my work.