We ship constantly — new system design problems, case studies, and platform features. Here's the running log. New tutorials drop almost every day.
ContentSeptember 28, 2026
Six more real-team case studies — AWS, Discord, Dropbox, Facebook, Prime Video & Slack
▸AWS: why it builds its own everything — Nitro, Graviton, SRD, Aurora and cells, and the economics of owning the stack. Dropbox: leaving the cloud for Magic Pocket. Discord: storing trillions of messages from Cassandra to ScyllaDB.
▸Facebook's October 2021 backbone outage, Prime Video's move back to a monolith (and what it actually says about serverless), and Slack's Vitess migration and move to cells. All 15 case studies are now live, each rebuilt from primary sources.
▸Chapter and case-study pages now ship only their own content, rendered ahead of time — up to 300× less JavaScript per page, so long chapters open faster.
ContentSeptember 27, 2026
Five new specialization tracks — money, SaaS, performance, migrations, security — and 8 new case studies
▸Money & Ledger Systems — modelling money, double-entry ledgers at scale, payment flows and unknown outcomes, reconciliation, settlement & payouts, fraud & disputes, and continuous correctness. 7 chapters.
▸Multi-Tenant SaaS Architecture — tenancy models and their economics, tenant isolation, noisy neighbours, live tenant migration, per-tenant keys, metering & billing, and enterprise demands. 7 chapters.
▸Performance Engineering & Tail Latency, Large-Scale Migrations, and Security Architecture — 7 chapters each, from queueing theory and coordinated omission to online schema changes, terabyte backfills, Zanzibar-style authorization and supply-chain security.
▸Eight new real-team case studies, each rebuilt from primary sources: GitHub's 43-second split brain, Roblox's 73-hour outage, CrowdStrike's Channel File 291, Cloudflare's regex outage, Shopify's pods, Stripe's data movement platform, Uber leaving Postgres, and Instagram scaling PostgreSQL.
A month of building, live today — all 8 tracks, Judgement, Leadership, Case Studies & 17 problems
▸Three new Architect tracks, 7 deep chapters each: SRE / Reliability (SLOs, observability economics, metastable failure, resilience patterns, incident command, chaos, blast radius), Cloud Ops (Kubernetes in production, platform engineering, IaC at scale, serverless economics, networking & mesh, multi-region, cost engineering), and API & Integration Design (contracts, REST vs GraphQL vs gRPC, versioning, idempotency, webhooks, gateways & auth, integration patterns).
▸Architecture Judgement — 8 essays on the decisions senior engineers get wrong: trade-off reasoning, when microservices are wrong, choosing messaging, the limits of serverless, signals to redesign, reviewing a design, when Postgres is enough, and designing for the next order of magnitude.
▸Technical Leadership — 7 essays for staff+ engineers: build vs buy, technical debt, outsourcing, making the case to non-engineers, leading without authority, knowing what not to build, and writing that drives decisions.
▸Seventeen new system design problems at architect depth — 8 HLD (collaborative editor, ride-sharing, photo sharing, file sync, video streaming, web crawler, search autocomplete, leaderboard) and 9 LLD rebuilt as real concurrency and correctness problems with Java 21 code (parking lot, LRU cache, ticket booking, elevator, vending machine, expense sharing, library, chess, logging framework).
▸Real-team Case Studies launch: sourced, cross-checked deep dives into how real teams built and broke their systems — starting with how Figma horizontally sharded Postgres. More landing weekly.
▸How data moves from the systems that run your product to the systems that answer questions about it: OLTP vs OLAP, columnar storage & the lakehouse (Parquet, Iceberg, Delta), and batch pipelines with Spark, dbt and Airflow.
▸Then the streaming half: Kafka & the log, stream processing with Flink and real-time analytics, change data capture with Debezium, and event sourcing & CQRS. 7 chapters, hand-illustrated.
Specialization Tracks 03 & 04 — Distributed Systems & Databases
▸Distributed Systems Deep Dive — consistency models, replication, consensus (Raft/Paxos), clocks & ordering, transactions & sagas, and CRDTs. 7 chapters.
▸Databases from the Inside — B-trees vs LSM, indexing, MVCC, the WAL, query planning, replication & sharding, and beyond-relational stores. 7 chapters.
▸The second Architect specialization track is live: serving at scale, GPU infrastructure, fine-tuning, guardrails, observability, and reliability/cost/rollouts.
▸Seven deep chapters, hand-illustrated — the operator's counterpart to AI-Native Architecture.
New System Design Problem — Design a Chat & Messaging System
▸A full staff-level walkthrough: the WebSocket connection layer and session routing, zero-message-loss durable delivery, ordering, presence, offline/push, and group fan-out.
▸8 themed diagrams, capacity math, failure modes, and the interview angle.