Shopify's beta launched on PostgreSQL, with replication set up only two days before launch. The founders quickly hit a hard limitation: Postgres of that era could not apply schema and data migrations without downtime, so after a weekend spent trying every available Postgres replication option, Tobi made the call to move the whole database to MySQL instead.

“in the end I just had to make a judgement call and went to mysql”

Postgres, as it worked at the time, could not apply schema changes to a replicated database without taking the site down, which Tobi considered untenable for a live e-commerce host handling other merchants' livelihoods.

“Postgres can be the second coming of jesus but it's still utterly infeasible for high traffic web applications because of the replication issue”

Before Tobi could even take his first snowboard payment on Snowdevil, he had to send notarized copies of his own passport to a payment processor in American Fork, Utah just to get the API keys needed to accept credit cards.