Open to opportunities

Denys Piven

@denyspiven

Message

Senior Java developer crafting secure, scalable microservices for enterprise systems.

Ukraine

Message

What I'm looking for

I’m looking for a role where I can build secure, scalable Java back-end systems and microservices—modernize legacy code to cloud-native architectures, optimize performance, and deliver reliable products in cross-functional teams.

I’m a Senior Java Developer with 7+ years of experience designing and building robust, scalable, and secure back-end systems. My work spans multiple domains—banking and financial services, e-Commerce, healthcare, and IT service management—where reliability and compliance matter.

I specialize in distributed microservice architectures and modernization of legacy systems into cloud-native solutions, including high-performance data processing pipelines. In recent roles, I’ve led migrations (e.g., a legacy Java 8 monolith into a cloud-native, serverless AWS architecture), implemented secure service communication, and strengthened authentication and security for regulated environments.

I also enjoy collaborating end-to-end across teams—pairing with designers, front-end developers, and stakeholders to deliver stable software. From optimizing PostgreSQL performance and improving loading times to developing Jira/Confluence extensions and automating testing, I consistently focus on clean delivery, measurable improvements, and maintainable systems.

Experience

Work history, roles, and key accomplishments

Current

Senior Full Stack Developer

Current

Fairstone

Nov 2025 - Present (7 months)

Supported and optimized banking applications to ensure security, reliability, and regulatory compliance. Migrated a legacy Java 8 monolith to a cloud-native, serverless AWS architecture using Lambda, API Gateway, Cognito, and KMS.

Java 8 TypeScript AWS Lambda API Gateway Cognito AWS KMS Websphere JSF MySQL

Senior Full Stack Developer

Eldermark

Jan 2025 - Feb 2026 (1 year 1 month)

Developed and maintained scalable Spring Boot web applications and improved PostgreSQL performance to reduce response times. Delivered performance-focused features, performed code reviews, and contributed to agile sprint planning and retrospectives.

Spring Boot Groovy TypeScript Vue PostgreSQL Docker AWS REST APIs Agile

Senior Backend Developer

Webaroo

Mar 2024 - Jan 2025 (10 months)

Designed and built backend architecture for an AI-driven product from scratch to deliver high performance. Implemented a fault-tolerant microservice architecture with real-time data processing pipelines and integrated machine learning components with front-end teams.

Spring Boot PostgreSQL Redis Elasticsearch Kafka Microservices Docker Kubernetes AWS

Middle Full Stack Developer

CompatibL

Aug 2021 - Mar 2024 (2 years 7 months)

Designed and implemented distributed microservices for high-availability trading systems. Migrated financial workflows to cloud-native storage and integrated risk management algorithms with real-time data processing pipelines.

C#Spring Boot Angular MySQL MongoDB RabbitMQ Docker Jenkins Azure

Middle Full Stack Developer

SysAid

Sep 2020 - Aug 2021 (11 months)

Developed RESTful APIs to integrate third-party IT tools and improved platform extensibility. Automated testing to increase coverage and supported migration of legacy systems to a cloud-native architecture for scalability and reliability.

Spring Boot React REST APIs PostgreSQL Docker Nginx Automated Testing Git

Junior Backend Developer

Broken Build

Jul 2019 - Sep 2020 (1 year 2 months)

Built Jira automation plugins using Atlassian APIs to streamline routine workflows and improve user productivity. Wrote technical documentation and conducted unit and integration testing to maintain code quality and reduce reported issues.

Java 8 Spring Boot Atlassian Junit PostgreSQL Linux Unit Testing Integration Testing Documentation

Junior Backend Developer

Tourstart ApS

Oct 2018 - Jul 2019 (9 months)

Delivered backend features for a motorcycle route planning platform, improving usability and expanding core functionality. Implemented services for dynamic routing and real-time data updates while collaborating with marketing and design teams.