Answers
What is the difference between UAT and SIT?
In short
SIT (System Integration Testing) proves the system works when integrated — across services, queues, APIs and third parties. UAT (User Acceptance Testing) proves the business outcomes the system was built for are actually delivered.
Short answer
SIT (System Integration Testing) proves the system works when integrated — across services, queues, APIs and third parties. UAT (User Acceptance Testing) proves the business outcomes the system was built for are actually delivered.
What this actually means in practice
SIT is owned by engineering and QA; UAT is owned by the business. SIT runs first, against integration contracts. UAT runs against business scenarios and is the formal gate before release. Both should produce traceable evidence — SIT against contracts, UAT against requirements.
The most common pitfall
Confusing the two and missing either the integration breaks or the business outcomes — both happen.
What to do next
Map your testing layers and assign ownership clearly before the next release cycle.
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.