Questions
9 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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09 / 10

What is the difference between a buffered and unbuffered channel?

An unbuffered channel synchronizes sender and receiver — both must be ready simultaneously. A buffered channel decouples them up to the buffer capacity, after which the sender blocks.

Buffered vs unbuffered channels
When to use each
  1. 1

    Unbuffered: guaranteed handoff, synchronization points, request-reply patterns

  2. 2

    Buffered: decouple producer and consumer speeds, absorb bursts, pipeline stages

  3. 3

    Buffered channels are NOT a substitute for proper back-pressure — a full buffer that never drains causes goroutine leaks

  4. 4

    Rule of thumb: start with unbuffered, add buffer only when profiling shows unnecessary blocking

  5. 5

    Closing a channel signals no more values — receivers drain remaining buffered values before seeing the zero value