Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
31 results for “DR Testing”
Restore Drill
A scheduled, timed exercise of restoring from backup into a clean environment — the only thing that converts a backup from a hope into a control.
Contract Testing
Verifying that a provider satisfies the expectations each of its consumers actually relies on, without running all the services together.
Load Testing
Driving a system with realistic traffic at a target volume to verify it meets its performance targets before real users do.
Active-Active vs Active-Passive
Whether all regions serve traffic simultaneously, or one serves while another waits to take over — a choice about which failure mode you would rather have.
Booking.com's Experimentation Platform
Booking.com runs over a thousand concurrent experiments and treats the ability to test any change safely as a platform capability rather than a product feature.
Chaos Engineering
Deliberately injecting failure into a system to discover, before an incident does, which of your resilience assumptions are false.
Disaster Recovery
The plan and capability for restoring service after an event that takes out a whole site, region or system.
Failback
Returning to the primary region after a failover, including reconciling the data written while it was unavailable — the half of DR that is usually unplanned.
Fitness Function
An automated check that an architectural characteristic still holds, run continuously rather than reviewed occasionally.
Game Day
A scheduled exercise in which a failure is deliberately introduced and the team responds as though it were real, to test the system and the response together.
LLM Evaluation
A repeatable measurement of whether an AI system's outputs are good enough, on cases that reflect the actual task.
Pilot Light
A disaster recovery posture where core data is continuously replicated and minimal infrastructure runs, with the rest provisioned only on failover.
Quality Attribute Scenario
A structured, testable statement of a non-functional requirement: source, stimulus, environment, artefact, response, response measure.
Service Quota
A per-account, per-region cap on how much of a resource may be used — a common and easily-avoided cause of scaling failures and DR failures.
Test Pyramid
A distribution of tests weighted towards many fast unit tests, fewer integration tests, and very few slow end-to-end tests.
A DR test fails: the secondary region cannot launch enough instances. What happened, and what standing checks prevent it?
What happened Service quotas in the secondary region are far lower than in the primary , because nothing has ever run there at scale. Quotas are per account and
A serverless API works in testing and fails under load with connection errors. The database is at 5% CPU. Explain and fix.
The mechanism Serverless functions scale by creating independent execution environments , each with its own process and its own connection pool. Two hundred con
Maersk rebuilt roughly 4,000 servers and 45,000 PCs in about ten days after NotPetya in 2017, and recovered its directory only because one data centre had been offline during the attack. What does this say about DR design?
The case, as publicly reported In June 2017 the NotPetya malware — destructive rather than financially motivated — propagated through Maersk's network, encrypti
Peak trading day is six weeks away and expected to be four times normal traffic. What do you do in those six weeks?
What the interviewer is testing Whether you can run a readiness programme rather than just "add servers", and whether you know what fails at peak that does not
TSB's 2018 core banking migration moved 1.9 million customers in a single weekend and failed publicly. What would you have required before approving that cutover?
The case, as publicly reported In April 2018 TSB migrated from a platform rented from Lloyds Banking Group to Proteo4UK, built by its parent Banco Sabadell. The
The business asks for "multi-region" after a regional outage. Before agreeing, what do you need to establish, and what are you actually signing up for?
What the interviewer is testing Whether you convert a vague requirement into numbers before designing, and whether you know that multi region is primarily a dat
You need to ship a rewrite of the pricing engine. Same inputs, same expected outputs, completely new implementation. How do you release it?
What the interviewer is testing Whether you know that release strategy is part of architecture, and whether you reach for verification techniques beyond "test i
Your system handles 1,000 requests per second today. Marketing says a campaign will bring 10,000 next month. What breaks first, and how do you find out?
What the interviewer is testing Whether you reason about bottlenecks systematically or start adding servers. The shape of the answer Scaling is not uniform. Som
DR Testing
Restore drills, timed against the stated RTO, into a clean environment.
Contract Testing
Verifying what consumers actually rely on, without a shared environment.
Load Testing
Realistic data, realistic mix, and a ramp rather than a step.
Resilience Testing
Exercising retries, breakers and fallbacks that are otherwise never run.
Soak Testing
Long runs that surface leaks and slow degradation.
Stress Testing
Pushing past target to learn what breaks first and how it fails.
Testing Strategies
The pyramid, and the contract tests distributed systems add to it.
Game Days
Testing the response — runbooks, access, comms — not only the system.