How to design & build systems and what would it cost you
As AI reduces costs, the skill in short supply shifts to a higher level – to decision-making: understanding what should be done, what shouldn't, and what tradeoffs matter. For engineers, this means product understanding and systems thinking are now essential about 5 years earlier than industry used to teach them.
A schema-flexible document store with secondary indexes, walked from a single in-memory collection up through leader-follower and leaderless quorum replication.
Ingest and query high-volume metrics: append-only columnar chunks, delta-of-delta + XOR compression, time-based block pruning, a label inverted index, and cardinality control.
An embedded, crash-safe KV store built on an LSM tree: WAL durability, memtable flushes, Bloom-filtered reads, compaction, and MVCC snapshots.