Search the practice set
126 questions, 454 terms and 400 topics in 20 areas.
12 results for “On-Call”
Layered Architecture
Organising code into horizontal layers — presentation, application, domain, data — where each layer may only call the one beneath it.
Linearizability
The strongest single-object guarantee — every operation appears to take effect instantaneously at some point between its call and its return.
Object-Level Authorization
Checking that the caller is entitled to the specific record they requested, not merely that they may call the endpoint.
Runbook
A short, actionable document telling an on-call engineer what an alert means, what to check, and what the safe mitigations are.
Semantic Cache
Caching model responses keyed by the meaning of the request rather than by its exact text, so near-duplicate questions are served without a model call.
Tool Calling
Giving a model a set of typed function definitions it can request to invoke, with the application executing the call and returning the result.
A downstream service slows from 50 ms to 3 s. Within two minutes every service in the request path is down, including ones that do not call it. Explain the mechanism and how you would have prevented it.
What the interviewer is testing Whether you understand that most outages are amplification, not failure — and whether you can name the specific mechanism rather
A team proposes CQRS for a CRUD admin panel because reads are slow. Is that the right call?
Why not CQRS here "Reads are slow" is a symptom with many causes, and CQRS addresses only one of them: the read and write models having genuinely different opti
A team proposes circuit breakers on every downstream call. What would you add, and why is the breaker not the most important control?
Why the bulkhead matters more A circuit breaker acts after it has detected a pattern of failure. During the seconds before it trips — and while its threshold is
When should a service call another synchronously, and when should it publish an event instead? Give me the deciding test, not a preference.
The deciding test Does this user action succeed or fail based on this callee's response? If yes, the call is synchronous, because you need the answer to decide.
You must roll out MFA to 40,000 employees. Security wants hardware keys; the service desk fears the call volume. Design the rollout.
The framing that resolves the argument Not every identity carries the same risk, so not every identity needs the same factor. A uniform mandate is what creates