Maksym

MAKSYM FEDENKO
Java Backend Developer | Vinnytsia, Ukraine | [open contact info](look above in the "contact info" section) | [open contact info](look above in the "contact info" section) | LinkedIn

SUMMARY:
Java Backend Developer with 5 years of commercial experience building and maintaining backend systems with
Java, Spring Boot, and Hibernate, including REST APIs, microservices, Kafka, and AWS. Strong focus on test
coverage, legacy system maintenance, and delivering robust, scalable solutions. Adept at contributing across the
full development lifecycle and working closely with cross-functional teams to ship high-quality software.

SKILLS:

• Languages: Java (8–17)
• Frameworks: Spring Boot, Spring Framework, Spring MVC, Spring Data JPA (JPA/ORM), Hibernate
• APIs & Architecture: REST API / RESTful Web Services, Microservices Architecture
• Messaging: Apache Kafka
• Databases: PostgreSQL, MySQL
• Cloud: AWS
• Testing: JUnit, Mockito
• Tools: Git, Maven, Gradle, IntelliJ, VS Code
• DevOps: Docker, Jenkins, Nginx, CI/CD
• AI-Assisted Development: Claude Code (spec-driven development), AI coding agents as part of daily
workflow

EXPERIENCE:

Java Backend Developer | ONSEO | November 2023 - Present
• Implemented new billing features in microservices application using Java and Spring Boot in a
multinational team, ensured 90% test coverage;
• Investigated existing system functionality and documented it on Confluence for better team understanding;
• Developed internal REST API dedicated to supporting testing processes.
Tech stack: Java 17, Maven, Spring Boot, MySQL, Kafka, AWS, Mockito, Splunk, Git

Java Backend Developer | VARTEQ Inc. | October 2022 - September 2023
• Improved and extended a large legacy School/University CRM system based on Java 8 and Struts by
using reverse engineering to understand the codebase
• Implemented new functionality and documented system behavior
• Performed troubleshooting, debugging, and ongoing maintenance to enhance user experience
• Presented newly developed features directly to the customer
Tech stack: Java 8, Struts 1.3, Maven, JAX-RS, MSSQL, Wildfly, Git

Java Backend Developer | Capgemini Engineering | December 2021 - October 2022
• Contributed to the development of a car rental service by designing clear and efficient APIs based on
business requirements
• Optimized SQL queries to improve REST API throughput and implemented hotfixes during critical
moments to enhance user experience
• Increased test coverage to improve system stability and reliability
Tech stack: Java 11, MyBatis, Flyway, JUnit, Mockito, Elasticsearch, Spring Framework, Microsoft Azure

Java Backend Developer | SoftServe | January 2021 - December 2021
• Built and maintained a service from scratch to compare CSV files, significantly improving QA efficiency
• Designed an automated pipeline for uploading files from backups
• Enabled QA engineers to quickly identify differences for testing purposes
• Reduced testing time up to 40% by automating CSV file comparison pipeline
Tech stack: Java 8, Spring Framework, Hibernate, JUnit, Mockito, Git

PROJECTS:

uptime-hero — Personal SaaS Project (in development)
• Building a lightweight website-uptime monitoring SaaS from the ground up, covering backend architecture,
checking logic, and notification flow
• Prioritized making the core uptime-checking engine reliable and thoroughly tested before layering on
additional features
• Built a separate configurable Go-based test service to simulate error codes and failure scenarios, used to
load-test the uptime checker at 1000+ concurrent requests
• Using Claude Code in a spec-driven workflow to build the frontend, referencing established products like
UptimeRobot for UX
Tech stack: Java, Go, TypeScript, Docker, Claude Code

EDUCATION:
2020 - 2021 | Mate academy
Computer Software Engineering Certificate
2012 - 2016 | National Technical University Of Ukraine “Kyiv Polytechnic Institute”, Kyiv
Bachelor’s Degree in Foundry Engineering