Answers
What is mutation testing?
In short
Mutation testing introduces small changes (mutations) into your code and runs your test suite — surviving mutations mean your tests missed something.
Short answer
Mutation testing introduces small changes (mutations) into your code and runs your test suite — surviving mutations mean your tests missed something.
What this actually means in practice
It's a meta-test: it measures the quality of your tests, not your code. Run on hot paths sparingly; full-suite mutation testing is expensive. Use it to prove a critical module is actually tested, not just covered.
The most common pitfall
Optimising for mutation score on trivial code and ignoring real risk.
What to do next
Run mutation testing once on your most critical module and act on the survivors.
Frequently asked questions
Does Forth Systems help with this?
Yes — Forth Systems works with banks, payment institutions, insurers and infrastructure operators on exactly this kind of work. Engagements start with a fixed-scope assessment so you see the shape before committing.
How experienced is the team?
Engagements are staffed by named, UK-based senior engineers — not a rotating offshore pool. References from the second line of comparable clients are available on request.
Where are you based?
Edinburgh-based, delivering UK-wide with onsite presence in London and across Scotland as required.
How fast can we start?
Most engagements start within 2-4 weeks of a signed SoW, faster where an existing supplier framework is in place.