Skip to content

Tracks Drills Topics Technologies Tech stacks Skill areas

Tracks Drills Topics

Loading

Aporeon

Technical interview practice, from one developer to another.

About Support Privacy Terms Refund policy

Async & Concurrency

Event loops, blocking work, tasks, cancellation, threads, processes, synchronization, and concurrency limits.

24 drillsPractice one at a timeOrdered pathConcept questionComparison questionDebugging scenarioArchitecture scenario

Recommended start

Async concurrency vs parallelism

Separates overlapping I/O work from simultaneous execution across processing resources.

Easy~5 minStep 1 of 24

Practice this drill Choose another

Search

24 of 24 shown

1Async concurrency vs parallelismRecommended startSeparates overlapping I/O work from simultaneous execution across processing resources.Concept questionEasy~5 minPythonPractice 2Coroutine vs Task vs FutureExplains awaitable work, scheduled ownership, and eventual-result integration in asyncio.

Practice order

24 drillsOne at a time

1Async concurrency vs parallelismUp next / Easy / ~5 min
2Coroutine vs Task vs FutureMedium / ~10 min
3How asyncio schedules tasksMedium / ~10 min

Comparison questionMedium~10 minPython

Practice

3How asyncio schedules tasksBuilds a cooperative scheduling model for tasks, callbacks, readiness, and I/O polling.Concept questionMedium~10 minPythonPractice

4Diagnose a blocked event loopFinds synchronous I/O or CPU work that prevents the event loop from scheduling other tasks.Debugging scenarioHard~15 minPythonPractice

5Task ownership and fire-and-forgetExplains task references, exceptions, caller lifetime, shutdown, and durable-work boundaries.Architecture scenarioHard~15 minPythonPractice

6TaskGroup vs gatherCompares structured task ownership with ordered result aggregation and different failure behavior.Comparison questionHard~15 minPythonPractice

7Asyncio cancellation and cleanupTreats cancellation as cooperative control flow with reliable resource cleanup and propagation.Architecture scenarioHard~15 minPythonPractice

8Asyncio timeout and shieldingSeparates caller time bounds, cancellation propagation, and ownership of protected underlying work.Comparison questionHard~15 minPythonPractice

9Timeout BudgetsSets bounded timeout and deadline policies across callers, APIs, databases, and external services without hiding unknown outcomes.Concept questionMedium~7 min.NETASP.NET CorePractice

10Multiple asyncio task failuresDefines fail-fast, all-results, and partial-success behavior for concurrent asyncio operations.Architecture scenarioHard~15 minPythonPractice

11Asyncio synchronization primitivesChooses task synchronization by protected state, notification predicates, and limited capacity.Comparison questionMedium~10 minPythonPractice

12Asyncio race conditionsShows how task interleaving across await points can violate a multi-step invariant.Concept questionMedium~10 minPythonPractice

13Bounded asyncio queue pipelineDesigns backpressure, worker ownership, completion tracking, failure, and shutdown around asyncio queues.Architecture scenarioHard~15 minPythonPractice

14BackpressureExplains saturation signals and how systems shed, queue, throttle, or degrade before cascading failure.Concept questionHard~9 min.NETApplication InsightsASP.NET CorePractice

15Bound asyncio concurrencyPlaces semaphore and admission boundaries around scarce work without retaining unlimited tasks.Architecture scenarioHard~15 minPythonPractice

16to_thread vs run_in_executorCompares convenient context-propagating thread offload with explicit executor selection and ownership.Comparison questionHard~15 minPythonPractice

17Choose Python concurrency modelChooses a concurrency model from workload, libraries, isolation, runtime build, and operational cost.Architecture scenarioHard~15 minPythonPractice

18Python GIL and free threadingExplains conventional CPython thread execution and the optional free-threaded runtime boundary.Concept questionHard~15 minPythonPractice

19Python process pool failuresExplains serialization, import safety, start methods, worker failure, and data-transfer cost.Debugging scenarioHard~15 minPythonPractice

20ContextVar in async codeUses task-aware context for tracing while keeping business inputs explicit and correctly reset.Concept questionMedium~10 minPythonPractice

21Call asyncio from another threadUses documented thread-safe scheduling APIs and keeps event-loop objects confined.Architecture scenarioHard~15 minPythonPractice

22Graceful asyncio shutdownCoordinates admission stop, task cancellation or draining, resource closure, and bounded termination.Architecture scenarioHard~15 minPythonPractice

23Diagnose asyncio stalls and leaksCombines asyncio debug evidence, task inspection, warnings, profiling, and capacity signals.Debugging scenarioHard~15 minPythonPractice

24Streaming DataCovers large exports, uploads, and API responses where bounded memory matters more than convenience.Architecture scenarioMedium~10 min.NETASP.NET CoreC#Practice

4

Diagnose a blocked event loop

Hard / ~15 min

5Task ownership and fire-and-forgetHard / ~15 min

6TaskGroup vs gatherHard / ~15 min

7Asyncio cancellation and cleanupHard / ~15 min

8Asyncio timeout and shieldingHard / ~15 min

+16 more drills in this section

Async & Concurrency - Python Backend | Aporeon