Testing Methodologies

Writing code that works once is easy. Writing code that continues to work after 100 other developers have touched the codebase over two years is incredibly difficult. That is why automated testing is a mandatory skill for senior engineers.

"How would you test this?" is a standard follow-up question for almost every architecture, API design, or algorithmic problem in a technical interview.

What's Inside?

• The Testing Pyramid: What each layer catches, what it costs, and how ice-cream-cone CI dies.
• Test-Driven Development (TDD): Red-green-refactor with a real loop, and when not to TDD.
• Mocking & Stubbing: Isolating dependencies and testing edge cases effectively.
• Load & Performance Testing: Ensuring your system doesn't collapse under real-world traffic.
• Modern Test Runners: The evolution from Jest to Vitest, and native tools like Bun.

"Untested code is broken code."