Software quality assurance (QA) is the set of practices that prevent defects across the whole development process: standards, code review, automated tests, release checks and learning from incidents. Testing is one part of QA that finds defects in the running product. QA aims to reduce how many defects are written, not only to catch them late.
How does QA differ from testing
Testing checks a product against expectations and reports problems. QA looks at the process that creates the product and asks how to prevent those problems. A team that only tests finds bugs and fixes them. A team with QA also asks why the bug appeared and changes the way it works.
Which practices does QA cover
- Clear acceptance criteria before work starts.
- Code review on every change.
- Automated tests at several levels: unit tests, integration tests and end-to-end tests.
- Regression protection with a regression suite.
- Release checks, monitoring and a way to roll back.
- Post-incident reviews that lead to process changes.
What does a QA engineer do
A QA engineer designs the test strategy, builds automation, explores the product for problems scripts miss and works with developers on testability. In strong teams the role is closer to a quality engineer who improves the whole pipeline than to a person who clicks through screens at the end.
How much testing is enough
There is no fixed percentage. Cover what would hurt most if it broke, such as payments, sign-in and data loss, with fast automated tests, and spend less on rarely used corners. Measure confidence rather than coverage numbers; see testing software you didn't design.
How do AI coding agents change QA
Agents write code and tests quickly, which raises the volume of change that needs checking. Tests written by an agent can also pass without proving much, so a human must check that they test behaviour. Review habits matter more than before, as covered in how to review AI-generated code.
When should you add a QA engineer
Add one when releases cause regular surprises, when regression bugs return, or when developers spend large parts of the week on manual checks. A senior QA engineer pays back quickly by building automation and a release routine.
What tools does QA use
Common tools include a test framework for each language, a browser automation tool for end-to-end checks, a continuous integration service that runs tests on every change, and monitoring for production. Choose mainstream tools that your developers already know, so that tests are maintained by the whole team and not by one person. The tool matters less than the habit of running the checks on every change.
How do you measure quality
Track a few simple signals: how often releases cause incidents, how long a bug takes to fix, how many defects customers report and how long the test suite takes to run. Avoid chasing a single coverage number. A trend that improves over several months shows that the process works, and a trend that worsens shows where to look next.
What should you ask a partner about QA
Ask what runs on every change, who reviews code and how releases are rolled back. Ask to see a recent test report and an example of a bug that was prevented by process.
What this means when you hire through Miyagami
Every engineer is tested by an AI-native tech lead who works with AI every day. Senior QA engineers join your team and work on your pipeline directly. Engineers join your team full-time from €5,600 a month, with a shortlist within 3 working days and no recruitment fee. We replace at our cost if the fit is wrong, and we don't do part-time. See how we vet and pricing.
Short answers
Is QA the same as testing?
No. Testing finds defects in the product, while QA works on preventing them across the process.
What is the difference between QA and QC?
QA focuses on process and prevention. QC focuses on checking the product itself.
Do small teams need QA?
They need QA practices from the start, even if no one has the title.
Can AI replace QA engineers?
Agents help write and run tests, but people still decide what matters and check that tests prove something.
