Side Quests

Optional deep dives for the curious

What are Side Quests?

Side Quests are optional deep dives into topics that come up in the main learning path. They're for when you see something and think "but how does THAT work?"

You don't need to complete these to understand the main content. But if you're curious, they'll give you a deeper understanding of the underlying mechanisms.

How Bloom Filters Work

intermediate~15 min

A probabilistic data structure that can tell you if something is definitely NOT in a set. Learn about hash functions, bit arrays, and false positive rates.

SST FilesLSM DatabasesProbabilistic Data Structures

Binary Encoding Deep Dive

intermediate~20 min

How do we go from key-value pairs to bytes on disk? Learn about length-prefixing, varints, checksums, and why binary format design matters.

SST FilesFile I/OSerialization

Variable-Length Integers

Coming Soon

How to encode integers in 1-10 bytes instead of always using 4 or 8. The clever trick used by Protocol Buffers, SQLite, and RocksDB.

Building an LRU Cache

Coming Soon

Implement a Least Recently Used cache from scratch. Understand the data structures that make O(1) get and put possible.

The Linux Page Cache

Coming Soon

The invisible cache between your code and the disk. Why read() doesn't actually read from disk, and when fsync() matters.