Database Engineer
What's actually inside Postgres, RocksDB, ClickHouse, and Neo4j. SQL deep; Rust for performance; then build a KV store, LSM tree, columnar store, time-series and graph databases.
Course sequence
- 01
SQL Fundamentals
Not startedLearn SQL: the language for talking to databases. Used by literally every backend that stores anything. SELECT, JOIN, GROUP BY, aggregates, subqueries — once you have these you can answer any question your data can answer.
beginnersql10 lessons~3h - 02
SQL Intermediate
Not startedLevel up from SQL Fundamentals. Subqueries, CTEs, window functions, set operations, transactions, indexes. The SQL features serious analytics and reporting use every day.
intermediatesql7 lessons~2h - 03
SQL Advanced
Not startedBeyond SQL Intermediate. Indexes, query optimization mental model, complex joins, JSON, advanced window functions, recursive CTEs. The features behind serious analytics and reporting.
advancedsql7 lessons~2h - 04
Rust Fundamentals
Not startedLearn Rust: a systems language with the safety of a high-level one. Ownership, borrowing, pattern matching, zero-cost abstractions. Every lesson is hands-on with real cargo execution.
intermediaterust15 lessons~4h - 05
Rust Intermediate
Not startedLevel up from Rust Fundamentals. Ownership in depth, traits and trait objects, generics, lifetimes, iterator chains, Result/Option chaining, closures. The features that make Rust feel like Rust.
intermediaterust9 lessons~2h - 06
Rust Advanced
Not startedBeyond Rust Intermediate. Smart pointers (Box, Rc, RefCell), interior mutability, trait objects, declarative macros, unsafe basics. The features that close the gap between Rust and C++.
advancedrust7 lessons~2h - 07
C Fundamentals
Not startedLearn C: the language behind operating systems, embedded firmware, and the foundation of nearly every modern language. Manual control, explicit memory, no surprises. Every lesson is hands-on with real gcc execution.
intermediatec13 lessons~3h - 08
Build Your Own Key-Value Store
Not startedBuild a production-grade key-value store from scratch. You'll start with an in-memory hash map, add ordered iteration and TTL, persist with write-ahead logging, build sorted SSTables, implement the LSM tree read path with compaction and Bloom filters, and add ACID transactions with MVCC snapshot isolation. By the end you'll deeply understand LevelDB, RocksDB, Cassandra, etcd, and FoundationDB.
advanced15 lessons~4h - 09
Build an LSM Tree
Not startedBuild a Log-Structured Merge tree like LevelDB/RocksDB: memtables, SSTables, leveled compaction, k-way merge, bloom filters, write-ahead logging, crash recovery, and the engine behind Cassandra, RocksDB, ScyllaDB, and modern time-series databases.
advanced23 lessons~6h - 10
Build a Database from Scratch
Not startedBuild a fully functional relational database engine from the ground up. You'll implement a SQL parser, B-tree index, page-based storage, write-ahead log, ACID transactions, and a query planner — the same architecture used by SQLite, PostgreSQL, and MySQL. By the end, you'll understand exactly how every database you've ever used works internally.
advanced34 lessons~9h - 11
Build a Column Store
Not startedBuild a columnar OLAP engine like ClickHouse/Parquet: row vs column layout, RLE/dictionary/bit-packing encodings, vectorized execution, predicate pushdown, hash + sort-merge joins, and the storage layer behind Snowflake, BigQuery, and modern data warehouses.
advanced10 lessons~3h - 12
Build a Time-Series Database
Not startedBuild a time-series database like Prometheus/InfluxDB: ingest streams of (timestamp, value, labels), Gorilla compression for 10x storage savings, time-partitioned blocks, downsampling pipelines, PromQL-style queries, histograms with t-digest percentiles, and HA via federation/Thanos. The metrics infrastructure of every modern observability stack.
advanced10 lessons~3h - 13
Build a Graph Database
Not startedBuild a graph database like Neo4j/Memgraph: nodes + edges + properties storage, index-free adjacency for O(1) traversal, label/property indexes, Cypher-style query language, BFS/Dijkstra/PageRank algorithms, RDF triples and SPARQL alternative model, and the engine behind Twitter's social graph, fraud detection, and knowledge graphs.
advanced10 lessons~3h - 14
Build Your Own Search Engine
Not startedBuild a full-text search engine from scratch. You'll tokenize documents, build inverted indexes with positions, support boolean and phrase queries, rank with TF-IDF and BM25, add field boosts, compress posting lists with VByte+delta encoding, and even add spell correction. By the end you'll deeply understand how Lucene, Elasticsearch, Tantivy, and Meilisearch actually work.
intermediate13 lessons~3h
Create a free account to track your progress across this path.