Андрей

Andrey Tanchak
Java Backend Developer

EXECUTIVE SUMMARY
Java Backend Developer with 5+ years of experience in FinTech, banking, and high-load
systems, specializing in microservices architecture, distributed systems, and real-time data
processing. Strong expertise in Java (11–24), Spring Boot, multithreading, and performance
optimization. Experienced in designing scalable solutions, troubleshooting production
issues, and implementing secure, resilient architectures.

Proficient in Kafka, RabbitMQ, QuickFIX, and AWS services for cloud deployments. Skilled in
monitoring and observability using Prometheus, Grafana, Jaeger, and OpenSearch. Familiar
with Java Virtual Threads (Project Loom) for high-concurrency solutions, CI/CD, Argo
Workflows, and modern development tools such as GitHub Copilot for IntelliJ IDEA.

CORE SKILLS
- Languages & Frameworks: Java (11–24), Spring Boot, Hibernate, JPA, Akka, Javalin
- Concurrency: Multithreading, Virtual Threads (Project Loom), Reactive Programming
- Messaging & Protocols: Kafka, RabbitMQ, QuickFIX/J, WebSockets, REST API, SoupTcp
(Nassau)
- Databases: PostgreSQL, MySQL, H2
- Architecture & Patterns: Microservices, Monolithic Systems, High-Load Optimization,
Design Patterns, SOLID
- Cloud & Tools: AWS (EC2, Cognito, S3, RDS), Docker, Kubernetes, Argo Workflows, IntelliJ
IDEA + Copilot
- Monitoring & Observability: Prometheus, Grafana, Jaeger, OpenSearch
- Testing: JUnit, Mockito, Stress Testing, Code Coverage
- Other: Git, Atlassian tools, Swagger, Gradle, Maven

PROFESSIONAL EXPERIENCE

Raiffeisen Bank (Raiffeisen Business Online)
Java Developer | 07.2024 – Current

- Developed and maintained both monolithic applications and microservices in a regulated
enterprise banking environment.
- Designed and implemented new services and optimized existing ones for high
performance and scalability.
- Integrated Kafka for asynchronous event-driven communication.
- Implemented distributed tracing and observability using Jaeger, Prometheus, Grafana, and
OpenSearch for log analysis.
- Automated deployments and workflows using Argo Workflows and Kubernetes.
- Used GitHub Copilot (IntelliJ IDEA) to improve coding efficiency and accelerate feature
delivery.
- Investigated and resolved production issues (root-cause analysis, SLA compliance).
- Collaborated with DevOps, QA, and frontend teams to ensure smooth delivery.
- Participated in code reviews, release planning, and on-call rotations for production
support.

m8fintech (Contract Projects)

Gary-Spiro
Java Developer | 01.2022 – Current

- Development of crypto-trading systems using Akka actors with the ability to trade on 8
major exchanges (OKX, Binance, FTX, Huobi, etc.).
- Implemented Virtual Threads (Java 21/24) to optimize concurrency and improve system
throughput.
- Designed and implemented new components and optimized system for high load and low
latency.
- Worked with Akka for concurrent and distributed processing.
- Debugged and resolved performance bottlenecks in production.
- Implemented unit and integration tests using JUnit and Mockito.

Will-Cabangon (Comet by AAAEquities)
Java Developer | 01.2023 – 03.2024

- Developed a monolithic stock monitoring system (Comet by AAAEquities) for the
Philippines stock market from scratch. Multi-user system receiving data via SoupTcp
WebSocket, processing it, and emitting via WebSocket or REST API.
- Leveraged Java Virtual Threads (Project Loom) for handling large numbers of concurrent
WebSocket connections efficiently.
- Designed and developed backend architecture and components from zero.
- Implemented authorization and authentication using AWS Cognito and JWT.
- Built WebSocket and REST APIs for real-time and historical data.
- Integrated Prometheus and Grafana for monitoring and metrics visualization.
- Performed stress testing and implemented rate-limiting strategies.
- Independently implemented an algorithm for generating candlestick data (daily, monthly).

Konstantinus
Java Developer | 11.2023 – 02.2024
- Developed microservices for real banking transactions and price monitoring.
- Built an order-placing microservice that processed requests and generated FIX messages
for QuickFIX/J.
- Implemented a price monitoring microservice that analyzed pricing data and optimized
performance before publishing to RabbitMQ.
- Deployed services on AWS EC2 and integrated with Docker pipelines.
- Debugged and resolved critical issues in production.

Incoresoft
Java Developer | 06.2019 – 06.2020

- Worked on a large microservice system that processed video streams from cameras to
recognize faces, car numbers, colors, and other attributes.
- Designed and implemented new components for the car-parking service.
- Developed database schema and integrated with JOOQ and Hibernate.
- Covered core logic with JUnit tests and improved test coverage.
- Debugged and fixed issues to ensure stable system behavior.
- Collaborated with other teams (face detection, car number detection) for integration.

EDUCATION
Odessa State Academy of Civil Engineering and Architecture – Management and
Administration (2020)
Hillel IT School – Java Development (2021)

LANGUAGES
English – Professional working proficiency
Ukrainian – Native
Russian – Native