// CHANGELOG

What's shipping

We ship constantly — new system design problems, case studies, and platform features. Here's the running log. New tutorials drop almost every day.

ContentSeptember 7, 2026

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.
Check it out →
ContentSeptember 4, 2026

Specialization Track 02 — LLM Ops

  • ▸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.
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ContentSeptember 4, 2026

Two new System Design Problems — Notification System & Distributed Cache

  • ▸Design a Notification System — a queue-backed multi-channel fan-out pipeline: prioritization, deduplication, retries, and delivery tracking.
  • ▸Design a Distributed Cache — consistent hashing, eviction, replication, cache invalidation, stampede protection, and the hot-key problem.
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ContentAugust 31, 2026

Specialization Track 01 — AI-Native Architecture

  • ▸The first Architect specialization track is live: RAG, vector search internals, LLM serving infrastructure, agent orchestration, evals, and cost/latency engineering.
  • ▸Richly illustrated with hand-built visuals — a reference architecture, the RAG pipeline, an HNSW search graph, the agent loop, and more.
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ContentAugust 30, 2026

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.
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ContentAugust 28, 2026

New System Design Problem — Design a Rate Limiter

  • ▸Token bucket vs leaky bucket vs sliding window, atomic distributed counters in Redis, and fail-open vs fail-closed.
  • ▸9 themed diagrams and a production-grade deep dive.
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FeatureAugust 28, 2026

Refer friends & bring your team

  • ▸Refer a friend — when they upgrade to a paid plan, you get a free month of Architect, credited automatically.
  • ▸Team plans: roll out Architect to your whole engineering org with volume pricing (5–9 seats save 15%, 10+ save 25%), one bill, and email invites.
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ImprovementAugust 27, 2026

Faster pages & clearer learning paths

  • ▸Trimmed and progressively-rendered the large content hubs for snappier loads.
  • ▸Made the learning-path labeling honest end-to-end: the Introduction is free, with Intermediate and Advanced unlocking on Pro and Architect.
FeatureAugust 20, 2026

Annual billing

  • ▸Pay yearly and save — Pro at $90/yr and Architect at $150/yr, alongside the monthly plans.
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FeatureAugust 18, 2026

Academy Recorded Cohort — buy instantly

  • ▸The $799 Recorded Cohort (lifetime access + 3 years of Architect) is now a one-click purchase — no callback required.
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ContentAugust 10, 2026

YouTube Companion Diagrams

  • ▸The actual diagram boards from the videos — 27 architecture teardowns you can browse and study, free with a signup.
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ContentAugust 5, 2026

System Design Problems section

  • ▸The classic 'design X' interview drills, done properly — starting with the URL Shortener and News Feed, with HLD and LLD tracks.
Check it out →