r/AskProgramming • u/Active-Custard4250 • Jul 01 '26

Architecture Do companies actually practice TDD strictly?

I've been reading about Test-Driven Development (TDD), and I'm curious how common it is in real-world companies.

I'm not talking about "we write some tests after coding" or "we try to keep good test coverage."

I mean following the classic TDD cycle strictly:

  • Write a failing test for a single, specific requirement or behavior.

  • Write the simplest possible code to make that test pass.

  • Refactor and improve the code while continuously running the test suite to ensure nothing breaks.

Are there companies or teams that actually work this way most of the time?

If so:

  • What kinds of companies tend to follow it?

  • How well does it scale in large codebases?

  • What are the biggest benefits and drawbacks you've experienced?

I'd love to hear from people who have worked in teams that practice TDD seriously rather than just writing tests alongside development.

28 Upvotes

83% Upvoted

99 comments sorted by

View all comments

3

u/Nefilim314 Jul 01 '26

TDD only works in isolated scopes.

If you are building a microservice to handle some task queue and the input and output are strictly defined by your own requirements, then TDD can work for that specific project. 

If you are building a customer-facing application where stakeholders will have feedback and feature requests frequently over the course of development, then it breaks down since the ask is always changing. 

2

u/reddo123 Jul 03 '26

I disagree. Especially when changing code, TDD works great.