Hollow & Co survived its biggest drop on two small servers

The shape of the business

Hollow & Co makes stoneware in small batches. Four times a year the studio releases a collection, sends one email, and sells out within minutes. Almost all of the year's revenue happens in those four windows, and the rest of the time traffic is a trickle.

That shape is brutal for a store: a platform sized for the trickle falls over at the drop, and one sized for the drop costs a fortune to idle.

Self-hosting on purpose

Riley wanted to own the store outright and to know exactly what it could take. Mercury runs on two four-core machines behind a load balancer, with Postgres on a third. The checkout holds a reservation on stock for ten minutes, so oversells are impossible even when three thousand people press the button at once.

• Load tested to 4,200 checkouts a minute before the first drop, on the same hardware.
• Stock reservations are ledger holds, released on timeout, so the sold-out state is exact.
• Order confirmation emails queue and drain over the following hour instead of blocking the checkout.

Black Friday

The winter collection went live at 09:00 Pacific. Two thousand two hundred orders in eleven minutes, peak database load at 38%, no alerts. The studio watched it happen on the ledger in the admin.

I refreshed the dashboard expecting something to be wrong. It just kept counting.

Hollow & Co has since added a subscription for seconds and studio samples, modeled as recurring orders, which smooths the revenue between drops.