July 08, 2024•Simon Hørup Eskildsen (Co-founder & CEO)In late 2022 I was helping my friends at Readwise scale their infrastructure ahead of the launch of Readwise Reader (read-it-later app). We wanted to build a highly requested feature: article recommendations and semantic search using vector embeddings. Readwise was paying ~$5k/month for their relational database, but we found that vector search on the same 100m+ documents would've cost $20k/month+! This wasn't just expensive; it meant we had ...