System Internals Deep Dives

Deep dives help you defend component choices after the high-level design is on the board. Focus on data layout, write path, read path, replication, failure handling, and operational knobs.

Study Anchors

• Kafka - partitions, consumer groups, retention, ordering, and replay.
• Redis - event loop, data structures, persistence, clustering, and Lua scripting.
• DynamoDB - partition keys, hot keys, secondary indexes, and capacity modes.
• Postgres - indexes, MVCC, transactions, query planning, and replication.
• Cassandra - LSM storage, quorum reads/writes, compaction, and tombstones.

Visual Enrichment Steps

Use Docs visual enrichment workflow for read/write path diagrams. Best candidates: Kafka producer-to-consumer flow, Redis single-thread execution path, DynamoDB partition routing, Postgres MVCC tuple lifecycle, and Cassandra write/compaction path.