The books
A guided tour of what Synapse can do: rendered diagrams (Mermaid and D2), clickable D2 walkthroughs, any code block openable in a full editor and run in a sandbox, step-by-step visualisations of that code, an interactive coding problem with a hidden test suite, architecture write-ups that live in the lesson beside the diagram, and a library of copy-and-adapt D2 templates — static and animated — for data structures, algorithms and system design.
A definitive system-design book that ramps from beginner to expert: DDIA-grade theory on an interview-ready spine, plus the production engineering behind real systems. 71 lessons across ten modules — foundations, data & distributed systems, infrastructure building blocks, named key technologies, patterns, fourteen end-to-end case studies with clickable C4 walkthroughs (closing with a capstone: the platform serving the book itself), production operations, and an interview playbook. Every claim sourced, every diagram rendered.
Data Structure & Algorithms Step by Step From Basics to Advanced.
Python from first steps to advanced — control flow, working with data, how Python really works under the hood, object-oriented design, and advanced features.
Java from first steps to advanced — control flow, classes and objects, the core libraries, robust object-oriented design, and advanced topics.
A practical, senior-grade SQL course — from foundations and joins to aggregation, window functions, CTEs and recursion, schema design, indexing and performance, transactions, and advanced patterns.
Cross-cutting reference material that belongs to no single subject: the tooling around the platform, how it is set up, and what it has taught us.
How the platform you are reading was designed, built and is operated — architecture and low-level design drawn from the real code, with UML, the decision record and the prices each decision paid, the technology stack and what it cost, the git-to-production content pipeline and the in-app path that turns a reader's fix into a pull request, and a case study of the four-node homelab it runs on: measured latency, real failure modes, and the outage that taught it fault tolerance. Every diagram matches the source; every number was measured — including the ones that later proved an earlier chapter wrong.