Євген

YEVHEN KLYMENKO
MIDDLE JAVA BACKEND DEVELOPER

CONTACT PROFILE
[відкрити контакти](див. вище в блоці «контактна інформація») Middle Java Backend Developer with over 4 years of experience in building
scalable enterprise systems and microservices. Expert in Java (8–21) and the
[відкрити контакти](див. вище в блоці «контактна інформація») Spring Boot ecosystem. Proven track record in extreme API optimization
(reducing latency from 30s to 2s) and successful migration from monolithic to
Maliutianka Village, Kyiv microservices architecture. Recognized for high productivity in multi-project
Oblast, Ukraine environments and the ability to maintain delivery standards under challenging
yevhen-klymenko-dev conditions. Experienced in mentoring junior developers and promoting Clean
Code principles.
YevhenLeonidovich
WORK EXPERIENCE
HARD SKILLS Middle Software Engineer | Calaton Systems OCT 2025 - FEB 2026

Languages: Java (8–21), SQL. API Performance Tuning: Optimized REST API response times and
Frameworks: Spring Boot, Security, significantly increased system throughput.
Architectural Migration: Led the transition of a 2016 legacy monolithic
Data JPA, Hibernate, Drools Engine.
system to a modern microservices architecture, enhancing scalability
Architecture & APIs: Microservices, and maintainability.
REST API, Kafka, Spring Cloud, Multi-Project Delivery: Successfully managed and delivered several
OpenFeign. concurrent CRM projects, maintaining high code quality and meeting
all deadlines without blockers.
Databases: PostgreSQL, MySQL,
Technical Mentorship: Mentored junior developers through regular
MongoDB, Redis.
code reviews, promoting SOLID principles and Clean Code standards
Tools & Infrastructure: Docker, AWS, within the team.
Digital Ocean, Liquibase, Mongock, Operational Resilience: Maintained 100% delivery stability and high
Maven, Gradle, Git, JobRunr, Caffeine productivity during challenging infrastructure conditions (power
outages) by effectively adapting work schedules.
Cache.
Testing: Unit & Integration Testing Junior Software Engineer | Calaton Systems DEC 2022 – OCT 2025
(JUnit, Mockito). AI & Cloud Integration: Developed the "Linguamill" language app
backend, integrating OpenAI API and cloud infrastructure (AWS,
Firebase) for automated content processing.
SOFT SKILLS Backend Development: Implemented complex business logic and
secure API endpoints using Spring Security and JPA for enterprise
Technical Mentorship CRM solutions.
Quality Assurance: Achieved high reliability through comprehensive
Problem-Solving Unit and Integration testing, ensuring stable production releases.
Resilience & Reliability
Intern / Trainee | Calaton Academy FEB 2022 – DEC 2022
Adaptability Feature Engineering: Developed backend modules for an educational
Effective Communication platform using Java 11 and Spring Boot.
Financial & Data Systems: Integrated Stripe payment gateway and
implemented data persistence strategies using PostgreSQL and Redis.
LANGUAGES
English (Upper-Intermediate)
Ukrainian (Native)
Russian (Fluent)