Lessons · new

Learn how it works

Lessons on how systems like Rasputin work: one idea per lesson, practiced on your own computer, with Rasputin as the worked example.

Each lesson teaches one idea you can use anywhere, and uses Rasputin as the real example. The labs run on your own computer. In some you build something in a folder you make for the lesson; in others you ask public systems a question and read the reply. A few lessons are for reading only and have no lab. None of them needs Rasputin hardware, Rasputin code or an account.

A lesson is written for one reader: beginner (new to the field), intermediate (knows the basics and wants the tradeoff) or advanced (a practitioner who wants how it is built).

This section is new. The lists below show only lessons that are published, and more are being written.

All lessons

System shape · Beginner The parts of a small distributed system System shape · Intermediate One image, role chosen at boot Engineering records · Beginner How to read a decision record Engineering records · Intermediate Runs on, tested on: reading a support claim Changing state · Beginner Why every change goes through one path Changing state · Intermediate Converge or act once, derive or store Changing state · Advanced A multi-step change with no undo Names · Beginner How a name becomes an address Names · Intermediate Two names instead of one name with two answers Names · Advanced How an authoritative nameserver answers, and where it breaks Firewalls · Beginner How a firewall decides Firewalls · Intermediate Declaring firewall rules instead of editing them Overlay networks · Beginner What an overlay network is Overlay networks · Intermediate Embedding a server or running it beside you Overlay networks · Advanced Why a listed route still carries nothing Intrusion detection · Beginner Detecting traffic is not stopping it Intrusion detection · Intermediate What a detection-only decision gives up Certificates · Beginner Why a browser warns about a private certificate authority Certificates · Intermediate Why a vendor's signing CA and each installation's CA stay separate Messaging · Beginner How machines send each other messages Messaging · Intermediate Choosing a transport for machines that come and go Compatibility · Intermediate What an old reader does with a new field Compatibility · Advanced Building a reader that refuses one tile, not the catalog Passkeys · Beginner Why a passkey belongs to one name Passkeys · Intermediate What passkey-only sign-in costs Version numbers · Beginner Why software has version numbers Version numbers · Intermediate What a calendar version stops telling you Signing · Beginner What a signature proves that a checksum does not Signing · Intermediate Why a second signing key needs its own purpose CI gates · Beginner What a passing check proves CI gates · Intermediate Which checks can stop a merge Updates · Beginner How an update can fall back Updates · Intermediate Rolling an update across a fleet Updates · Advanced How a machine proves an update worked Provisioning · Beginner What provisioning gives a new machine Provisioning · Intermediate Why first boot stops instead of guessing Monitoring · Beginner What a heartbeat, a metric and a log line tell you Backup · Beginner How you know a backup works Backup · Intermediate Why restore is never automatic Backup · Advanced A backup the service writes and cannot read

Track: Network engineer 18 lessons

18 lessons are published in this track so far, in reading order.

Beginner The parts of a small distributed system Beginner How to read a decision record Beginner How a name becomes an address Beginner How a firewall decides Beginner What an overlay network is Beginner Why a browser warns about a private certificate authority Beginner Detecting traffic is not stopping it Beginner What a heartbeat, a metric and a log line tell you Intermediate One image, role chosen at boot Intermediate Runs on, tested on: reading a support claim Intermediate Converge or act once, derive or store Intermediate Two names instead of one name with two answers Intermediate Declaring firewall rules instead of editing them Intermediate Embedding a server or running it beside you Intermediate Why a vendor's signing CA and each installation's CA stay separate Intermediate What a detection-only decision gives up Advanced How an authoritative nameserver answers, and where it breaks Advanced Why a listed route still carries nothing

Track: Software developer 17 lessons

17 lessons are published in this track so far, in reading order.

Beginner The parts of a small distributed system Beginner How to read a decision record Beginner Why every change goes through one path Beginner How machines send each other messages Beginner Why a passkey belongs to one name Beginner Why software has version numbers Beginner What a passing check proves Intermediate One image, role chosen at boot Intermediate Runs on, tested on: reading a support claim Intermediate Converge or act once, derive or store Intermediate Choosing a transport for machines that come and go Intermediate What an old reader does with a new field Intermediate What passkey-only sign-in costs Intermediate What a calendar version stops telling you Intermediate Which checks can stop a merge Advanced A multi-step change with no undo Advanced Building a reader that refuses one tile, not the catalog

Track: DevOps 15 lessons

15 lessons are published in this track so far, in reading order.

Beginner The parts of a small distributed system Beginner How to read a decision record Beginner Why software has version numbers Beginner What a passing check proves Beginner What a signature proves that a checksum does not Beginner How an update can fall back Beginner What provisioning gives a new machine Intermediate One image, role chosen at boot Intermediate Runs on, tested on: reading a support claim Intermediate What a calendar version stops telling you Intermediate Which checks can stop a merge Intermediate Why a second signing key needs its own purpose Intermediate Rolling an update across a fleet Intermediate Why first boot stops instead of guessing Advanced How a machine proves an update worked

Track: Operations 16 lessons

16 lessons are published in this track so far, in reading order.

Beginner The parts of a small distributed system Beginner How to read a decision record Beginner What provisioning gives a new machine Beginner What a heartbeat, a metric and a log line tell you Beginner How an update can fall back Beginner How you know a backup works Beginner Why a browser warns about a private certificate authority Intermediate One image, role chosen at boot Intermediate Runs on, tested on: reading a support claim Intermediate Converge or act once, derive or store Intermediate Why first boot stops instead of guessing Intermediate Rolling an update across a fleet Intermediate Why restore is never automatic Intermediate Why a vendor's signing CA and each installation's CA stay separate Advanced How a machine proves an update worked Advanced A backup the service writes and cannot read