Testing protects your investment. It catches errors early, when they are cheap to fix, and lets the software change safely over the years. Here is what the different test types do.
Unit tests
Test small pieces of code – a price calculation, a validation rule – in isolation. They run in seconds and are written by developers alongside the code.
Integration tests
Check that components work together: the application with the database, or your system with an external API.
End-to-end (E2E) tests
Simulate real users clicking through the application: log in, create an order, check the confirmation. Tools like Playwright or Cypress automate these flows in browsers; similar tools exist for mobile apps.
Performance tests
Measure how the system behaves under load: many users at once, large data volumes, slow networks.
Security tests
Automated scans for known vulnerabilities in code and dependencies, plus manual reviews or penetration tests for sensitive systems.
User acceptance tests (UAT)
Your key users test the software with real scenarios before go-live and confirm it meets the requirements. This is where business knowledge matters most.
Regression testing
Every change can break something that worked before. Automated test suites run on every change (continuous integration) so regressions are caught immediately.
The testing pyramid
Many fast unit tests at the bottom, fewer integration tests in the middle and a small number of end-to-end tests at the top. This balance keeps tests fast and reliable.
What you should expect from a development partner
- Automated tests for critical business logic
- A test environment separate from production
- A test plan for acceptance testing
- Bug tracking with clear priorities
- No release without passing tests
Testing is part of every sprint in our projects, not a phase squeezed in at the end.