Elixir Tutorial: Building a Worker Pool from Scratch Using Raw Process Primitives

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A new installment in a DEV Community series on distributed systems in Elixir demonstrates how to build a worker pool without relying on GenServer, OTP Supervisors, or third-party libraries like Poolboy. The tutorial explains why spawning an unbounded number of processes for large workloads causes problems such as resource exhaustion, CPU thrashing, and lack of backpressure. To address this, the guide constructs a bounded concurrency system using only Elixir's raw primitives: spawn, send, and receive. The pool architecture consists of three components — a parent process, a coordinator, and a fixed set of worker processes — where the coordinator manages job queuing and worker availability. The series aims to help developers understand the underlying mechanics of load coordination before adopting higher-level abstractions.

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