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Coding agents can produce changes faster than a team can explain why those changes were authorized, how they were verified, and who accepted the risk of putting them into production.

Solar Frontiers is a strategy game I have been building.

I procrastinate the way I have always procrastinated: instead of writing the book, I build tools that help me write the book.

I write books in plain Markdown.

A reader stopped on the fifth word of my novel and asked whether it had been translated from Swedish.

Every thriller has the scene.

The Problem Erlang gives a function two visibility states.

A recent essay, "The Isolation Trap", argues that Erlang's isolation model has structural limits: deadlocks from circular calls, unbounded mailboxes, and escape hatches like ETS.

Many teams can answer what a piece of code does, but far fewer can explain why it exists, what constraint shaped it, which tradeoff led to it, and whether that reasoning still holds, and that gap matters more now because we produce and change code at a pa…

The Late-Night Feeling of Wonder In 1980 my ten years older sister started university and brought home a TI-58 programmable calculator.

Why I Built a Course on the BEAM Programming languages shape how we think.

Observers: The Watchful Gnomes of the Village Some gnomes in the village don’t build bridges, bake bread, or carry mail.

Gatekeepers: The Traffic Controllers of the Gnome Village In every gnome village you eventually discover a small, serious-looking gnome standing on a bridge, holding a sign.

Routers: The Gnome Village Mailmen Routers are the mailmen of the gnome village.

The Gnome Who Guards the Chest of Gold In the gnome village, not every gnome runs around performing tasks.

In the gnome village, a Worker is the simplest citizen you can have.

Process Archetypes: The Roles in the Gnome Village The BEAM makes it easy to create thousands of processes.

Glossary: Resource owner = the process that owns mutable state for a domain object.

Glossary: Resource owner = the process that owns mutable state for a domain object.

Glossary: Resource owner = the process that owns mutable state for a domain object.

Glossary: Resource owner = the process that owns mutable state for a domain object.

Build a Village of Gnomes, Not a Park of Machines In the last post, The Gnome Village, we explored how the BEAM turns concurrency into cooperation.

The Gnome Village I see some developers that arrive at the BEAM carrying mental luggage from object-oriented or sequential programming.

TL;DR Fake recruiters are pushing a malicious “crypto poker” codebase.

Why "Exactly Once" in Payments Is a Myth, and What Works Instead Payment systems live with retries.

The Spy Dolls Under the Dance Floor “A dirty spy.”

Why I wrote the Beam Book After ten years of keeping Klarna’s core system upright I know this: a 15 millisecond pause in the BEAM can stall millions of peak-shopping payments, trigger a 3 a.m.

Your Finance Stack Is Lying to You Why Untyped Data, Floats, and “Excel Thinking” Are Quietly Costing You Millions At a recent fintech conference, I was struck by how much engineering effort, across both startups and enterprises, is spent cleaning up avoi…

AI Rubber Ducking: When Your Duck Starts Talking Back We’ve all been there.

The Project Nears Completion I set out to document everything I knew about the BEAM, and to discover everything I didn't yet know.

Fintech is a ruthless game.

Setting Up an AI-Powered Personal Coach Introduction Why do our ambitious goals often fizzle out by the third week?

Technical authors often brace themselves for GitHub issue notifications-each ping might herald a misplaced comma, a misunderstood explanation, or worse, a confusing typo deep within a critical code snippet.

Hyperchains: Your Own L1 Chain Hyperchains are here.

Synchronous vs.

RabbitMQ: The Undeserved Reputation There’s a common claim floating around that RabbitMQ is unreliable.

Forget Microservices: Just Use Erlang.

The Hidden Cost of Bad Payment Architecture If you've ever tried to fix a broken payment system, you know it's never just one thing.

Opinions: Just the Facts, 11 Years Later A decade ago, I wrote a blog post declaring my distaste for opinions.

Microservices Are NOT an Excuse for Chaos Too many teams think "microservices" means "no rules."

Rebar3 is the standard build tool and package manager for the Erlang programming language.

Why Windows 11 Virtual Desktop Switching Is Slow If switching between virtual desktops in Windows 11 feels slow, you're not alone.

Developer Productivity This post outlines the structure behind the paid developer productivity course: motivation, habits, time, workflow, collaboration, and tools.

Developer Productivity for Experienced Engineers This post is an audience-specific note from the paid developer productivity course.

Developer Productivity for Early-Career Engineers This post is an audience-specific note from the paid developer productivity course.

This is the third entry in a series of posts on devcontainers; the first entry is here.

Enhancing Fintech Security with Erlang: Insights from HappiHacking As the former CTO of Klarna and the founder of HappiHacking and Kindio, I've spent years at the intersection of financial systems and security.

Handling high-volume transactions efficiently is a must in fintech.

In Europe, the way people pay for things is changing.

The prototyping Monkey is a bit sceptical because he got two managers instead of developers to take over his product...