How distributed systems are put together, including the Learning Maps films that each explain one design pattern.
20 posts · all topics
I built the smallest loop that could be wrong, to watch a law from Ashby do work. The loop was wrong twice before it was evidence, the law turned out not to apply, and the real cluster already knew the fix. All of it measured, and explained from the ground up.
Change the drag constant in my arcade game by one part in a hundred million and twelve recorded runs stop matching. That strictness is the foundation the replays, the scoreboard, the co-op and the releases all stand on.
One of my health checks stayed red for eleven weeks by reading its own failure. A loop is the special case of a trajectory, the path that happens to close, and a life does not.
Twenty-one rooms each taught one durable idea. The capstone movement spends them. Four real systems designed end to end, every move naming the principle it came from, so the whole map reviews itself through practice.
The cost movement continues. The Promise is how you pay less for the load you can count on. The Shelf is how you pay less for what you store, and the bet hidden in every cheaper shelf.
The security wing closes. The Lobby is about what should even be reachable in the first place. The Cipher is the last line, where the data itself is useless to a thief without the key.
The security wing of Learning Maps opens. The Keyring is how you stop handing out master keys. The Gauntlet is why one lock is never enough, and how to stack locks that fail for different reasons.
The room about beating distance. A CDN opens a branch in every town so the answer is already next door, and it closes the systems-talking wing of Learning Maps.
Two short films on how a system takes a punch. The Breaker is how you stop one slow dependency from dragging the whole desk down. The Allowance is how you keep one greedy caller from eating the counter.
Two short films that open the services-talking arc of Learning Maps. The Book Drop is how one part of a system hands work to another without waiting on it. The Greeter is how a crowd of requests gets spread across a fleet that can lose a machine and not miss a beat.
Two short films that open the coordination story of Learning Maps. The Vote is how a cluster of unreliable machines agrees on one leader and one truth. The Ring is how the pieces survive machines coming and going all day.
Six short films on what happens to data the moment it stops fitting on one machine: the forced choice, the dial, taste, the cache, the branch library, the shard. The first wing of Learning Maps, the durable principle under each rented AWS label.
Just Enough Agreement is Episode 3 of Learning Maps, a Napkin Films series that turns system design into story. Strong consistency is the expensive default, a cathedral when a sticky note would do. The skill is buying the cheapest guarantee the story actually needs: read your writes, monotonic reads, session consistency. Hand drawn on a napkin, narrated by two cloned voices, scored with a 14 Hz focus layer. CC BY 4.0.
The Dial is Episode 2 of Learning Maps, a Napkin Films series that turns system design into story. Consistency is not on or off. It is a dial you set by counting: with N copies, when your reads plus your writes are greater than N, a read is forced to overlap a write and see the latest truth. Hand drawn on a napkin, narrated by two cloned voices, scored with a 14 Hz focus layer. CC BY 4.0.
AWS is taught as two hundred services. Underneath it is a handful of primitives, and every service is a frozen answer to a distributed-systems trade-off. The map I built studying for the SAA-C03, and the two questions that decode any new AWS service.
The Forced Choice is Episode 1 of Learning Maps, a new Napkin Films series that turns system design into story. A storm takes down the phone line between two librarians, and what happens next is the deepest fact in distributed systems: the CAP theorem, its twin PACELC, and the trade every database has already made. Hand drawn on a napkin, narrated by two cloned voices, scored with a 14 Hz focus layer. CC BY 4.0.
Microservices used to be a tax a solo builder could not afford. AI agents change that math. Here is why I am drawn to the architecture for what I build next, and the discipline that keeps it from becoming a mess.
How I work in agent mode with Claude Code: a CLAUDE.md file as the specification, whole subsystems handed over, and AWS infrastructure built by describing what should exist, not typing it.
I asked Claude to help me understand my own blog's deployment pipeline. What came back was not better code but better questions, and that is what conversational mode is for.
Advanced patterns from a game I built. Interfaces, metadata, batch operations, and what it takes to make code a machine can actually work in.