Questions
2 of 10
1Explain the fan-out and fan-in concurrency pattern with a practical example.
2How does the select statement work with multiple channels, including a default case?
3How does Go's GMP scheduler work and how does it affect concurrency design?
4Describe how you would approach a Go service that needs to process Kafka events with exactly-once semantics.
5What is a goroutine leak and how do you detect and prevent one?
6When should you use sync.Mutex vs channels for shared state?
7How would you implement a distributed task queue in Go without using an external framework?
8What is a goroutine, and how does it differ from an OS thread?
9What is the difference between a buffered and unbuffered channel?
10Design a worker pool for processing 100,000 jobs with back-pressure and graceful shutdown.
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02 / 10

How does the select statement work with multiple channels, including a default case?

select blocks until one of its cases can proceed, choosing randomly when multiple are ready. A default case makes it non-blocking, executing immediately if no channel is ready.

select patterns
Important behaviors
  1. 1

    When multiple cases are ready, select picks one uniformly at random — no priority ordering

  2. 2

    Nil channels are never ready — use this to dynamically disable a case

  3. 3

    time.After creates a new timer and channel on every call — use time.NewTimer in loops to avoid leaks

  4. 4

    default makes select non-blocking — runs immediately if no channel is ready

  5. 5

    select with only a default case and no channels is a spin loop — avoid