backend engineer · Poland
Mateusz
Jaskulski
I build backends where the numbers have to add up: virtual economies, inventories under concurrent access, and sync between devices that are offline half the time. Shipping to production since 2021.
- statusemployed
- focusbackend
- dbpostgresql
- since2021
Experience
career.yml
run #2021 · on: push to main · 0/4 jobs passed
total 5y 6m · still running
Side projects
built after hours
Kuba owes you 80.00 PLN
Split
Expense splitting the server can't read. Encrypted event log, key in the invite link, balances computed on the device, works offline.
typescript · workers · d1 · webcryptosplit.mateq.dev ↗
POST /transfers · 201 Created
Banking API
Transfers through one conditional update: no negative balances and no deadlocks under a 16-thread stress test. Idempotent retries, double-entry ledger.
java 17 · spring boot 3 · postgresqlgitlab ↗
13:30 · logged in 4 s
Remi
Diet and symptom tracker built around one rule: logging a meal takes less than five seconds. Runs on my homelab.
vue 3 · fastapi · postgresql · duckdbremiapp.net ↗
ESPI · new quarterly report
GPW data
Own Warsaw Stock Exchange database with a ranking, filings alerts and a backtest that counts whole shares and broker fees.
python · postgresql · scrapingprivate repo