Drills

Set timeout budgets across downstream dependencies

Sets bounded timeout and deadline policies across callers, APIs, databases, and external services without hiding unknown outcomes.

.NETASP.NET Core

Stream an authorized file download

Authorizes metadata before opening storage and streams the file with safe headers and range support.

.NETASP.NET CoreC#

Comparison questionMedium~7 min

Synchronous vs asynchronous service communication

Selects synchronous calls, asynchronous messaging, or a deliberate combination based on user feedback, coupling, latency, durability, and failure behavior.

.NETASP.NET CoreAzure Service Bus

Test an endpoint capability matrix

Expresses allowed and denied capability combinations as one parameterized API integration test.

.NETASP.NET CoreC#EF CoreSQL+1

Test an idempotent POST retry

Proves repeated requests with one idempotency key create one resource and return a consistent result.

Test a resource ownership boundary

Proves that one authenticated user cannot read or modify another user's private resource.

Test cancellation of a slow downstream call

Uses a controllable fake HTTP handler to prove request cancellation reaches a downstream dependency.

Test stable pagination across timestamp ties

Walks API pages through equal sort values and verifies no duplicate or missing resource ids.

Coding problemEasy~15 min

Test validation through the ProblemDetails contract

Verifies status, content type, stable error extensions, and field errors for an invalid API request.

Debugging scenarioHard~12 min

Thread pool starvation symptoms in an ASP.NET Core API

Diagnose an ASP.NET Core API that becomes slow because request threads are blocked or exhausted.

.NETASP.NET CoreC#

Concept questionHard~9 min

Trace full-stack user actions in production

Explains tracing one user action across browser, frontend server, API, dependencies, logs, metrics, and safe diagnostics.

.NETASP.NET CoreNext.jsReactTypeScript

.NETASP.NET CoreC#EF CoreSQL

Update one property without loading the entity

Attaches a key-only stub and marks one property modified for a narrow update while naming the rules this pattern bypasses.

Use a circuit breaker around an unhealthy dependency

Explains closed, open, and half-open behavior, failure classification, recovery probes, and the limits of circuit breakers.

.NETASP.NET Core

.NETASP.NET CoreJWTOAuth2OpenID Connect

Use an external identity provider without losing app authorization

Explains the boundary between OAuth/OIDC identity, application users, claims mapping, roles, and app-specific permissions.

Concept questionHard~9 min

Use a Next.js backend-for-frontend with an ASP.NET API

Explains when a Next.js route layer helps with cookies, tokens, aggregation, and UI-specific API adaptation.

.NETASP.NET CoreNext.jsReactTypeScript

Use ASP.NET Core policies for authorization

Explains policy-based authorization, requirements, handlers, claims, capabilities, and resource-aware checks.

.NETASP.NET CoreJWT

.NETASP.NET CoreEF CoreSQL

Use DbContext pooling without leaking request state

Uses EF Core context pooling only when reusable context state, tenant isolation, and underlying connection state are controlled and tested.

.NETAmazon SQSAzure Service BusRabbitMQ

Use delayed and scheduled messages

Explains delayed delivery, scheduled work, reminders, retry timing, cancellation, and clock-related trade-offs.

.NETASP.NET CoreEF CoreSQL

Use ExecuteUpdate instead of loading entities for bulk changes

Explains when set-based EF Core updates are better than loading entities and where lifecycle behavior can differ.

Architecture scenarioHard~12 min

Use If-Match preconditions to prevent lost updates

Connects HTTP preconditions to atomic database concurrency checks and honest 412 or 428 API behavior.

.NETASP.NET Core

ASP.NET CoreNext.jsReactTypeScript

Use Next.js route handlers as an API boundary

Explains route handlers as a frontend server boundary for cookies, API adaptation, auth, and backend calls.