Ask HN: What is the most enlightening concept that changed how you program?

Lambda calculus. Applied functions and recursion. Everything else is syntactic sugar on imperative do.. lists.

Typed arguments as strong pre requirements to intent, and the cost/benefit of typechecks.

What do I actually do? Boring imperative python3.

I wish I'd learned LISP as my first language. It was literally a left door right door choice to do Fortran on cards, and then Pascal. Two people teaching the induction classes. I went through the Fortran->Pascal door.

If I'd turned left, I would have entered the other cohort who started with LISP.

1. type safety from typescript avoids lots of bugs before running my code

2. linters like eslint forces best practices and readability in my code

3. security is learnable from online sources like latacora blog and owasp cheatsheets

4. reading latest docs and github issues helps a lot in debugging.

5. reading readme file and getting started guides is more reliable than watching video tutorials.

6. videos however are good at getting comparisons and seeig presentations of ideal use cases of particular tool software or database or framework

We had moved to fully typed python using mypy and ruff and using framework that highly benefit from it https://litestar.dev . It greatly improved our code quality , our understanding of python and how python work . At first it is tedious and felt over engineering but it's totally worth it.

Functional programming. Clojure changed how I write C#, Python, and think about storing data.

I now think much more about immutable, append-only data stores as a result.

Functional programming - I realised that state is one of the greatest enemy and that it is possible to write programs without it.