Hello,

My name is Maksim. I am a Senior Java Backend Engineer with 6+ years of experience building and scaling revenue-critical payment and crypto processing systems in banking and fintech.

In my current role, I acted as a technical lead for a team of three engineers, building a QR payment platform from scratch. The system processes 18M+ transactions annually and directly contributes to multi-million annual revenue. I was responsible for core architectural decisions — enforcing idempotent execution, designing rate-limited REST integrations, and implementing end-to-end observability to guarantee financial traceability and production stability under high load.

In parallel, I designed and implemented an ISO 8583-based crypto transaction processing engine, handling message parsing, transaction classification, and routing to external crypto exchange services, processing ~22,000+ operations daily with dynamic configuration via Redis and zero-downtime updates. I also worked on crypto card infrastructure, including card lifecycle operations and integration with core banking systems and external card processors (Visa/Mastercard, HUMO), covering secure PAN handling, transaction flows, and partner-facing APIs.

Additionally, I redesigned and scaled a high-load transfer service generating ~$4.56M in annual commission revenue. By introducing asynchronous AML execution, batched job processing, and multi-instance-safe orchestration, I ensured predictable scaling to ~500 RPS peak. I increased payment conversion from 64% to 89% and eliminated a double-payment race condition that had been causing ~$146K in monthly financial losses.

My focus is ownership of complex financial and crypto flows: building resilient architectures, optimizing transaction pipelines, and ensuring system stability under high load. I am interested in roles where backend engineering directly impacts business metrics and system performance.

I would welcome the opportunity to contribute as a senior engineer who can deliver independently and take responsibility for critical systems. Here's my CV: https://docs.google.com/document/d/1rp4d5L-gXHBckb-0fHewIEKFnBMBqOkbR6bHN4T7Zy0/edit?usp=sharing