$ whoami

hi, i'm denys

Java backend engineer · fintech & payments

I build the systems that move money — order matching engines, payment gateways, ISO 8583 message parsers. I'm interested in performance, correctness, and the surprisingly interesting world of financial infrastructure.

about me projects →

# featured projects

forge-gateway

↗ github

REST API gateway for fintech demos. Handles auth (JWT), order routing, and health checks. Spring Boot 3 + Java 21.

Java 21
Spring Boot
JWT
PostgreSQL

order-matching-engine

↗ github

In-memory limit order book with price-time priority matching. Sub-microsecond latency on a single thread — no locks.

Java
LMAX Disruptor
FIX Protocol

iso8583-parser

↗ github

Zero-dependency ISO 8583 message parser and builder. Handles bitmap parsing, BCD encoding, and custom field specs.

Java
ISO 8583
Fintech

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