Concurrency Patterns in Go

Why Go?

Go's concurrency model based on CSP (Communicating Sequential Processes) is a game changer for backend services. Unlike Node.js event loops, Go allows us to spawn lightweight threads (goroutines) that are managed by the Go runtime.

The Fan-Out/Fan-In Pattern

One of the most useful patterns for processing large datasets.

func worker(id int, jobs <-chan int, results chan<- int) {
    for j := range jobs {
        results <- j * 2
    }
}

func main() {
    jobs := make(chan int, 100)
    results := make(chan int, 100)

    for w := 1; w <= 3; w++ {
        go worker(w, jobs, results)
    }
}

By fanning out the work to multiple workers and fanning the results back in, we reduced our image processing pipeline latency by 80%.