Simon Eskildsen

Simon Hørup Eskildsen is co-founder and CEO of turbopuffer, a search database built on object storage. He grew up in Denmark and moved to Canada to work on infrastructure at Shopify for almost a decade.

Scaling Shopify

When he joined Shopify's infrastructure team in 2013, the platform handled hundreds of requests per second. By the time he left, peaks regularly passed one million, as he recalled on the Software Engineering Daily podcast.

The Readwise napkin math

Afterward he helped friends at Readwise, the reading app, tune their Postgres database and try an early recommendation feature built on embeddings. It worked, but the cost did not. “It was going to cost 30 grand a month, and this was a company, it was a bootstrap Canadian company. They spent about 5k a month on all the other infrastructure combined,” he told Gergely Orosz in a Pragmatic Engineer conversation. Readwise did not ship it.

He kept asking why storing vectors was so expensive, and sketched a design that kept the data in S3 and organized it for fast reads. “I spent the summer of '23 just hammering my head against the wall trying to find an approach where I can get the latency that I wanted,” he said. That design became turbopuffer, which Readwise itself now uses.