Jakub Nowosad

I joined Soleback’s three founders in 2024 as the fourth person on the team, and run development end to end: six services behind one public API, a web app, a Chrome extension, an admin panel, and the monitors that feed all of it. Reads come from Redis first and fall back to Postgres. When it threw intermittent 5XX, the cause was four separate things stacked, not one.

An HR and payroll system for DRE$$CODE and Dropsy: time tracking, leave, employee records, per-project settlement, and the mBank transfer batches at the end of it. I designed the data model first, then built the NestJS API over it, with four clients going on top: web, iOS, Android, and a native macOS app that is furthest along. Personal data is encrypted field by field.

A drop is not steady traffic: everyone arrives in the same minute, and the checkout either holds or the launch becomes the story. Stores for people who already have an audience. 474747 for the rapper Oki, blaire.cc for Miłosz Kulesza’s brand, V24 STORE for an Eryk Moczko release. 474747 runs on WordPress, so capacity was mine to solve: on a drop it held over fifteen thousand people at once.

Eighteen affiliate networks, eighteen opinions about what a transaction is. Some expose a REST API, some fire postbacks, one drops a CSV into S3. All of it lands in one state machine (pending, approved, withdrawable), and every transaction is stitched back to the click that caused it. I own the pipeline; it has to be replay-safe, because partners resend.

42bot, written at school: software that bought limited-release sneakers faster than a person could. Stock monitors, checkout automation, and Discord bots in front of it. The sites did not want the traffic, so the budget was a few hundred milliseconds against a target that kept moving. It is where the monitor vocabulary comes from, and I now build the storefronts on the other side of that transaction.