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Alexandr Onyskiv

@alexandronyskiv

Message

Senior Java developer specializing in scalable backend systems and fintech/crypto integrations.

Belarus

Message

What I'm looking for

I seek backend or full-stack roles where I can build secure, high-performance systems, work with crypto/finance teams, and contribute across the stack while driving measurable business impact.

I am a Senior Java developer with over 15 years of experience designing and building backend applications, primarily using the Spring Framework and Vanilla Java. I focus on scalable microservices, high-load platforms, and financial/cryptocurrency systems.

I've delivered production integrations that increased exchange operations and onboarded customers by building crypto/fiat wallets and payment-routing solutions. I also developed event-driven trading automation that produced consistent revenue using Java, MongoDB, and real-time multithreaded decision logic.

My full-stack experience includes JavaScript and React on the client side and Ruby/Rails on several projects, enabling me to contribute across the stack and improve end-to-end product delivery. I have hands-on expertise with databases (Postgres, MySQL, MongoDB), messaging (RabbitMQ), and containerization.

I prioritize secure, performant systems — implementing TLS for inter-service communication and optimizing throughput with connection pooling and parallelized batch processes. I thrive in cross-functional teams focused on measurable business outcomes.

Experience

Work history, roles, and key accomplishments

Current

Java Developer

Current

Whitebird.io

Dec 2023 - Present (2 years 1 month)

Designed and built scalable backend services enabling inter-country payment routing and cryptocurrency/fiat wallet integrations, increasing exchange operation volumes and expanding customer reach through new financial-tool integrations.

Java Spring Framework PostgreSQL RabbitMQ Microservices REST APIs Linux

Algorithmic Trading Developer

Self Employed

Sep 2021 - Dec 2023 (2 years 3 months)

Built event-driven data collection and multithreaded trading control applications for cryptocurrency markets, plus prediction models and websocket services, generating average earnings of $8k/month.

Java MongoDB Python Pandas scikit learn WebSockets RabbitMQ Docker

Java / Full Stack Developer

Edovo

Oct 2016 - Dec 2021 (5 years 2 months)

Implemented Java server-side components and client-side features for rehabilitative correctional software, using JDBC/ActiveJDBC, Redis and React to deliver reliable features and data services.

Java JDBC ReactJS Redis MySQL Tomcat JavaScript Linux

Java Developer

TouchCommerce

Feb 2018 - Aug 2021 (3 years 6 months)

Developed and optimized high-load platform solutions, securing and improving inter-service communication (TLS for Java sockets, connection pooling) to meet corporate security and throughput requirements.

Java Spring Framework Apache Tribes TLS MySQL Performance Tuning

Java / Ruby Full Stack Developer

Exadel

Feb 2009 - Oct 2016 (7 years 8 months)

Contributed to multiple projects as server- and client-side developer, building REST/SOAP services, batch parallelization with JMS, and full-stack features using Java, Ruby on Rails and various databases.

Java Ruby on Rails Spring MVC Hibernate JMS MongoDB MySQL Oracle REST SOAP

Ruby / Full Stack Developer

EPAM Systems

Feb 2007 - Feb 2009 (2 years)

Worked on server- and UI-side components using Ruby on Rails and front-end technologies to deliver enterprise web applications integrated with Oracle databases.

Ruby on Rails JavaScript HTML CSS Oracle AJAX UI UX

Education

Degrees, certifications, and relevant coursework

Belarusian State University of Informatics and Radioelectronics

Informatics and Radioelectronics

Completed higher education in Minsk with graduation in 2008; focused on informatics and radioelectronics-related coursework relevant to software development.