What does a QA tester do and how to get started in software testing
The tasks of a junior QA, how to write test cases and report bugs, and which tools to learn to land your first testing job.
A QA (Quality Assurance) makes sure software works as it should before it reaches users. It's an excellent way into tech: attention to detail matters as much as code.
A day in the life of a junior QA
- Reading a user story and understanding what should happen.
- Designing test cases: the happy paths and, above all, the ones that can fail.
- Testing the app manually or with automated tests.
- Reporting bugs clearly so the team can fix them fast.
- Retesting once they're fixed.
How to write a good test case
Example: a transfer between accounts.
| Step | Data | Expected result |
|---|---|---|
| Transfer a valid amount | $100 | Balance drops by $100 and it shows in the history |
| Transfer more than the balance | $99,999 | "Insufficient funds" message; nothing changes |
| Zero or negative amount | $0 | The button doesn't let you continue |
Think about boundaries: empty, zero, negatives, the maximum allowed and one character too many.
How to report a bug
A good report has: a clear title, steps to reproduce, expected result, actual result, evidence (screenshot or video) and environment (device, browser, version).
What to learn
- Testing fundamentals: test types and test case design techniques.
- API testing with Postman.
- Basic SQL to verify data.
- Automation: Selenium, Playwright or Cypress for web tests.
- Git and working in a team with tickets.
Next step
Codea's free QA Engineer Jr route takes you from designing test cases to automating a simple flow, with banking examples. Route content is in Spanish.
Videos, hands-on challenges, quizzes and teacher reviews (route content is in Spanish).