Compute: rent, don’t buy

What it is

A single rented bare-metal server in a data centre that runs all development environments. Mine is a second-hand machine from the Hetzner server auction: an older Intel quad-core with 62 GB of RAM. Nothing fancy, but it runs around the clock, sits on a fast line and costs a two-digit euro amount per month.

Rent, don’t buy is the most important decision in the whole setup. A laptop with 64 GB of RAM costs several thousand euros, is outdated after a few years and still has only one battery and one fan. For that money the rented server runs for years, and if it’s no longer enough, I cancel it and rent a bigger one.

Its role

It’s the workhorse. Every repository an agent works on gets its own container there, with its own toolchain, dependencies, dev server and tests. Five to ten of them at the same time is normal.

For what agents do, memory is the scarce resource, not CPU time: every container holds its Node process, its language server, its test runner, sometimes a browser for end-to-end tests. 16 GB is enough to start with; with 64 GB you stop thinking about it. Many cores help when several agents build at once.

What it buys you: rent the machine, don’t buy a powerful laptop

That’s the real punchline. When the work happens on the server, the laptop is just a terminal with a nice screen. I work on a MacBook Neo: light, long battery life, great display, and more than fast enough for what it has to do. It doesn’t get warm when ten agents run npm install at the same time, because that happens elsewhere.

Also: with agents, I hardly type. I talk. For dictation I use Whispering, an open-source speech-to-text tool. Explaining to an agent for two minutes what I want is faster and usually more precise than writing it down.

And the agents keep working when the laptop lid is closed.

Alternatives

• Locally on the laptop. Works as long as it’s one or two agents. After that the laptop gets loud, hot and drained, and every trip interrupts the work.
• Cloud VMs billed by the hour (AWS, GCP, Hetzner Cloud). Flexible, but for a machine that runs all day anyway, much more expensive than dedicated hardware.
• Hosted environments like GitHub Codespaces. No plain SSH access, environments get stopped when idle, billed per hour and core, and you’re tied to one vendor. More on that under Hatchery.
• A machine at home. Works, but depends on your home connection and your home power supply.

Why this way

A rented, used dedicated server is the cheapest way to have lots of RAM permanently available, and the most convenient: I don’t have to buy, upgrade or carry any hardware. Development environments don’t need high availability: if the server dies, the code is still on GitHub, and the environments can be rebuilt on any other machine from their devcontainer.json files.