Deep-dives on the systems you actually use
Backend systems, understood — not memorised.
I learn one system at a time, to the point where I can make design decisions and read other people's code. These are those notes, rewritten as structured deep-dives — mental models first, gotchas included.
- Mental model first
- Taught to a rubric
- Real gotchas, not trivia
Topics
- redis.md Redis, from the ground up One thread, held in memory — and why that single design choice explains almost everything else. 14 min read
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elasticsearch/ 8-part series Elasticsearch Eight short deep-dives that build one mental model of Elasticsearch — from the inverted index to the design calls. Browse parts
- Start here — series guide 3 min read
- 1 Elasticsearch, from the ground up 11 min read
- 2 Documents, mappings & the shape of your data 13 min read
- 3 How Elasticsearch reads text: the analysis pipeline 12 min read
- 4 The Query DSL: match, term, bool & the two contexts 12 min read
- 5 Why results come back ranked: BM25 relevance 11 min read
- 6 Aggregations: the analytics engine 12 min read
- 7 Running at scale: shards, replicas & the write path 14 min read
- 8 When to reach for Elasticsearch (and when not to) 11 min read
- mysql.md Coming soon MySQL Indexes, transactions & the query planner queued