Building a Vector Search Library from Scratch
Feb 9, 2026 - Present
A deep dive into building a toy vector search library in pure Python. We implement approximate nearest neighbor (ANN) algorithms from scratch, exploring the tradeoffs between accuracy, speed, and memory.
Series
We start with the simplest approach: a flat index that compares every vector. Correct but impractical for large datasets.
We divide the vector space into clusters and only search nearby regions. A major speedup through strategic dimensionality reduction.