Not Invented Here
ELI5 — The Vibe Check
Not Invented Here (NIH) syndrome is refusing to use existing solutions because you didn't build them yourself. There's a perfectly good library that does exactly what you need? Nah, let's build our own from scratch. It'll only take... checks calendar ...six months. NIH is the developer ego's favorite anti-pattern.
Real Talk
Not Invented Here (NIH) is an organizational or individual bias against using external solutions, preferring to build custom implementations. While sometimes justified (security, performance, vendor lock-in), NIH often leads to duplicated effort, maintenance burden, and inferior solutions compared to battle-tested open-source alternatives.
When You'll Hear This
"We built our own auth system instead of using Auth0 — classic NIH." / "Sometimes NIH is valid, but not when you're rebuilding React from scratch."
Related Terms
Golden Hammer
The golden hammer is when you find a tool you love and use it for EVERYTHING — even when it's completely wrong for the job. Love React?
Library
A library is a collection of tools you can use whenever you want, however you want. You're in charge.
Open Source
Open source means the recipe is public. Anyone can read it, copy it, tweak it, and share their version. It's the opposite of a secret sauce.
Over-engineering
Building a rocket ship when you just need a bicycle.
Technical Debt
Technical debt is the coding equivalent of putting things on a credit card.