[nivertech]

I have code written 20+ y/o, which is still running in production at multiple places in the world. It's for non-trivial soft-realtime embedded system processing PBs of data in realtime, not some CRUD app which can be easily spit out by GitHub Copilot or ChatGPT.

But yes, every SW/HW/systems project should come with an expiration date. From quick-and-dirty or throwaway, to extended longevity/support.

It's important to choose the tech stack, architecture, and SDLC accordingly.

e.g. don't use ecosystem with accelerated bit rot like nodejs/npm for long-term projects. Similarly don't use C++, Rust, etc. for one-off scripts or prototypes.

Same for Agile/Scrum vs upfront design/RUP/mini-waterfall.

[tmaly]

What language is your 20+ year system written in?

I have a php system that has been going strong since 2005.

[nivertech]

Mostly C++ sprinkled with several scripting languages.

The compilation took hours, so hooks with an emebedded scripting language used to make changes to the system without recompilation.