Questions
6 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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06 / 10

When should you use sync.Mutex vs channels for shared state?

Use mutexes to protect shared data structures accessed by multiple goroutines. Use channels to communicate data or signal events between goroutines. Do not mix both patterns on the same resource.

Mutex use cases
  1. 1

    Protecting a shared cache, counter, or map from concurrent reads and writes

  2. 2

    RWMutex when reads dominate: many concurrent readers, rare writers

  3. 3

    Guarding a struct's internal state in a concurrent-safe type

  4. 4

    Short critical sections where channel overhead would be wasteful

Channel use cases
  1. 1

    Passing ownership of data between goroutines — only one goroutine holds the data at a time

  2. 2

    Signaling events: task completion, shutdown, rate limiting tokens

  3. 3

    Pipeline and fan-out patterns where data flows through stages

  4. 4

    Worker pool coordination: jobs channel distributes work, results channel collects output

Mutex for shared state example