Open to work

Karol Welc

Full-stack product engineer

I ship products end to end, from Go services and Postgres to the dashboard people actually use.

Poland · remote

Selected work

Things I built

Trading tooling, retail automation and the software that runs behind a shop.

Watches two bookmakers side by side and surfaces the price gaps while they still exist.

Role: Zero to production — backend, dashboard, browser extension

GoRedisPostgreSQLNext.jsTypeScriptDocker

VajraLive2026

A licensed drop-automation bot for Asian e-commerce and ticketing, plus the services behind it.

Role: Zero to production — bot, licensing backend, webhook relay, site

GoBubble TeachiSQLiteRedisasynq

uSignLive2026

Warehouse, consignment contracts and invoicing in a single panel for resellers.

Role: Supporting engineer — features and maintenance

Next.jsTypeScriptPostgreSQLKSeFShopifyWooCommerce

Toolbox

Credentials

Contact

Got a product to build, or one that needs someone to keep it running? Grab a slot, or drop me a line.

or email me at