Imagine a bustling airport with a limited number of runways (CPU cores). Thousands of flights (goroutines) need to take off and land efficiently. How do you prevent chaos and ensure no flight is stuck on the tarmac forever? Go’s answer to this air traffic control problem is its ingenious GMP scheduler. It’s the silent maestro conducting the orchestra of your concurrent code. In this article, we’ll move from the control tower view down to the runway tarmac, exploring how Goroutines (G), OS threads (M), and Processors (P) collaborate to keep your application’s traffic flowing smoothly, even during peak load.

Go’s concurrency story is powered by a user space scheduler built around three entities: G, M, and P. Understanding how the scheduler maps millions of goroutines onto a limited number of OS threads helps you write services that scale, diagnose latency spikes, and avoid resource pitfalls.

Go’s interfaces are very funny. Rather than being explicitly implemented, like in Java or Rust, they are simply a collection of methods (a “method set”) that the concrete type must happen to have. This is called structural typing, which is the opposite of nominal typing.

Go interfaces are very cute, but this conceptual simplicity leads to a lot of implementation problems (a theme with Go, honestly). It removes a lot of intentionality from implementing interfaces, and there is no canonical way to document that A satisfies1 B, nor can you avoid conforming to interfaces, especially if one forces a particular method on you.

It also has very quirky results for the language runtime. To cast an interface value to another interface type (via the type assertion syntax a.(B)), the runtime essentially has to use reflection to go through the method set of the concrete type of a. I go into detail on how this is implemented here.

Because of their structural nature, this also means that you can’t add new methods to an interface without breaking existing code, because there is no way to attach default implementations to interface methods. This results in very silly APIs because someone screwed up an interface.

Surf is a powerful, feature-rich HTTP client library for Go that makes working with HTTP requests intuitive and enjoyable. With advanced features like browser impersonation, JA3/JA4 fingerprinting, and comprehensive middleware support, Surf provides everything you need for modern web interactions.

Zek is a prototype for creating a Go struct from an XML document.

GoQueue is a flexible background job processing library for Go applications, designed to handle workloads of any scale with multiple backend options.

A powerful, real-time log analysis terminal UI inspired by k9s. Analyze log streams with beautiful charts, AI-powered insights, and advanced filtering - all from your terminal.

Previous posts Why Go is not my favourite language and Go programs are not portable have me critiquing Go for over a decade.

These things about Go are bugging me more and more. Mostly because they’re so unnecessary. The world knew better, and yet Go was created the way it was.

For readers of previous posts you’ll find some things repeated here. Sorry about that.

This Go package provides commonly used components for terminal based user interfaces.

Serilog-inspired structured logging for Go with message templates, rich formatting, and native Seq support

Mangle is a programming language for deductive database programming. It is an extension of Datalog, with various extensions like aggregation, function calls and optional type-checking.

We're excited to announce the release of Genkit Go 1.0, the first stable, production-ready release of Google’s open-source AI development framework for the Go ecosystem. Along with this release, we're also introducing the genkit init:ai-tools command to supercharge your AI-assisted development workflow.

Genkit is an open-source framework for building full-stack AI-powered applications. It provides a unified interface for multiple model providers and streamlined APIs for multimodal content, structured outputs, tool calling, retrieval-augmented generation (RAG), and agentic workflows. With Genkit Go, you can now build and deploy production-ready AI applications with the speed, safety, and reliability of Go.

A follow up to what is the go proxy even doing? now with more answers. Russ Cox (rsc) and I traded a few emails trying to work out what was going on. They’re going to make a few changes, and I also learned a few things it would have been helpful to know.

With the latest release of Go 1.25, there are two notable changes to the sync.WaitGroup type, both of which stem from common mistakes that developers make when using the WaitGroup type. In this post we are going to explore both of these changes and how they can help you avoid a common race condition.