Service Virtualisation
Standing in for a dependency you cannot call, and keeping the stand-in honest.
4 to work through
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intermediate
A grocery marketplace in the mould of Instacart integrates with 140 retailer systems for inventory lookup and order injection. A platform engineer proposes building a virtual service for each one so the test suite can run without them. Roughly what does that cost per year to keep faithful and how many of the 140 are actually worth virtualising?
3 min answer -
intermediate
When should external dependencies be virtualised in testing, and what must the virtual service reproduce?
2 min answer -
intermediate
You virtualised a mainframe dependency for testing. Six months later a production integration fails that all tests passed. What happened?
2 min answer -
advanced
A platform integrates with hundreds of external providers, and testing against them is slow, unreliable and sometimes impossible. What is the approach?
2 min answer
4 terms in this topic
Fake Drift
The divergence between a simulated dependency and the real one it stands in for - which makes tests pass while the real integration fails, producing …
practiceRecorded Interaction Corpus
A set of real request and response pairs captured from a live dependency and used to build and continuously re-verify its stand-in, so the fake repro…
conceptService Stub Fidelity
How faithfully a stand-in dependency reproduces the real one's behaviour — including its errors, latency and limits — which bounds what testing again…
toolService Virtualisation
A stand-in for a real dependency that responds with realistic data, latency and error behaviour, so a service can be tested without it.
Neighbouring topics
Testing & Quality Architecture
General material on designing a testing strategy as an architectural concern.
Test Architecture Strategy
Choosing what to verify where, given the failure modes that actually occur.
Test Pyramid Shapes
Pyramid, trophy and honeycomb, and the system properties that justify each shape.
Integration Test Boundaries
What sits inside a test's boundary, what is faked, and the confidence that follows.
Contract Testing at Scale
Keeping dozens of services compatible without an environment that runs all of them.
Consumer-Driven Contracts
Consumers declaring what they rely on, and providers verifying against those declarations.
Test Data Management
Realistic data without copying production personal data into a weaker environment.
Synthetic Data
Generating data with the shape and edge cases of the real thing, and where it misleads.
Environment Parity
The differences between staging and production that decide which bugs survive to release.
End-to-End Test Economics
Why broad end-to-end suites get slow, flaky and abandoned, and what to keep.
Non-Functional Test Strategy
Testing availability, latency, security and recovery rather than only behaviour.
Performance Test Design
Workload models, warm-up, think time, and the distribution the average hides.
Chaos as a Test
Fault injection with a hypothesis, a blast radius and an abort condition.
Security Testing in the Pipeline
SAST, DAST, dependency and secret scanning, and what to do with the findings.
Accessibility Testing
Automated checks, their ceiling, and the manual testing that has to sit above it.
Mutation Testing
Measuring whether tests would actually notice a defect, not just cover a line.
Flaky Test Management
Quarantine, detection, and the trust a suite loses once red stops meaning broken.
Testing in Production
Synthetic transactions, dark launches and shadow traffic, done deliberately and safely.
Quality Gates
Thresholds that block a release, who may override them, and how they decay.