Hello, I'm

Denys Ohorodnik

Senior Java Developer

6+ years building high-performance backend systems using Java, Spring Boot, and SQL/NoSQL. 70% database load reduction and 10K+ daily transactions in scalable microservices.

About Me

Senior Java Developer

With over 6 years of experience in building high-performance backend systems, I specialize in creating scalable solutions using Java, Spring Boot, and modern distributed technologies.

My expertise spans across microservices architecture, database optimization, and enterprise-level system design. I have a proven track record of solving complex technical challenges and delivering solutions that handle thousands of daily transactions with exceptional reliability.

6+ years of Java development experience
Master's Degree in Software Engineering
Enterprise-level project experience

Career Highlights

High-Performance Caching

Architected Hazelcast solution reducing database load by 70% and improving response time by 40%

Microservices Excellence

Led development of critical microservice handling 10,000+ daily transactions with 99.9% uptime

Legacy Migration

Migrated monolithic application to microservices, reducing deployment time from days to hours

Query Optimization

Optimized SQL queries processing millions of records, cutting execution time by 30%

Professional Experience

Senior Java Developer

Portum (via Modus Soft)

4 years 10 months

White-label SaaS for Cisco BroadWorks management serving 50K+ users with 10K+ daily transactions.

Architected high-availability infrastructure
Implemented Hazelcast caching solution
Led monolith to microservices migration
Optimized database performance

Java Developer

Avery Dennison D2Comm (via SoftServe)

8 months

Enterprise e-commerce platform for custom apparel labeling with cross-platform design editor.

Developed complex SQL queries
Improved response time by 25%
Built Python ETL pipeline
Processed 100K+ daily configurations

Trainee Java Developer

Home Away (via SoftServe)

8 months

Travel accommodation booking platform built with microservices architecture.

Implemented microservices architecture
Designed RESTful API endpoints
Created comprehensive unit tests
Optimized pagination and performance

Technical Skills

Comprehensive expertise in modern Java development, distributed systems, and enterprise-grade technologies with proven track record in high-traffic applications.

Backend Development

Java 21/17/895%
Spring Boot 3.x90%
Spring Data JPA88%
Spring Security85%
Hibernate 687%
JDBC85%

Distributed Systems

Hazelcast 5.390%
Apache Kafka88%
Redis85%
Spring Cloud82%
Microservices90%
REST API95%

Databases

MySQL 890%
PostgreSQL88%
Flyway85%
Query Optimization90%
Database Design87%

DevOps & Tools

Docker85%
Maven90%
Jenkins80%
Git95%
Linux82%
CI/CD85%

Monitoring & Testing

Prometheus80%
Grafana78%
JUnit 590%
Mockito88%
JMeter82%
Integration Testing87%

Methodologies

Agile (Scrum)90%
Kanban85%
TDD88%
Domain-Driven Design82%
Code Review90%

Core Technologies & Achievements

6+
Years Experience
Java Development
70%
Performance Boost
Database Load Reduction
10K+
Daily Transactions
99.9% Uptime
50K+
Active Users
Enterprise SaaS

Professional Projects

Enterprise-level projects demonstrating expertise in scalable backend systems, microservices architecture, and high-performance optimization.

Portum - BroadWorks SaaS Platform

Modus Soft4 years 10 months

White-label SaaS for Cisco BroadWorks management serving 50K+ users with 10K+ daily transactions. Led architecture and development of high-performance microservices.

Key Achievements:

  • Reduced database load by 70% with Hazelcast caching solution
  • Achieved 99.9% uptime handling 10,000+ daily transactions
  • Migrated from monolith to microservices architecture
  • Optimized SQL queries reducing execution time by 30%

Technologies:

JavaSpring BootSpring CloudHazelcastMySQLKafkaRedisAWS SNS/SQSDockerJenkins

Project Metrics

50K+
users
10K+ daily
transactions
99.9%
uptime
70% load reduction
performance
Enterprise SaaS

Avery Dennison D2Comm

SoftServe8 months

Enterprise e-commerce platform for custom apparel labeling with cross-platform design editor. Focused on backend optimization and ETL pipeline development.

Key Achievements:

  • Improved system response time by 25%
  • Built Python ETL pipeline processing 100K+ daily configurations
  • Refactored legacy Spring 4 components
  • Implemented asynchronous request processing

Technologies:

Java 8Python 2.7Spring 4PostgreSQLHibernate 4FlywayJenkinsGit

Project Metrics

25% faster
performance
100K+ daily
processing
25 members
team
Spring 4 → Modern
legacy
E-commerce Platform

Home Away Booking Platform

SoftServe8 months

Travel accommodation booking platform built with microservices architecture. Contributed to backend architecture and performance optimization.

Key Achievements:

  • Implemented microservices architecture for booking system
  • Designed RESTful API endpoints and database schema
  • Created comprehensive unit and component tests
  • Optimized pagination and performance based on benchmarking

Technologies:

JavaSpringHibernateJerseyKafkaJUnitPostgreSQLSwaggerGitJenkins

Project Metrics

Microservices
architecture
Full Coverage
testing
8 members
team
RESTful Design
api
Travel Platform

Open Source & Personal Projects

Explore my algorithm implementations, Spring Boot demos, and modern Java development patterns on GitHub. Including circuit breaker implementations, Kafka streaming, and performance optimization examples.

View GitHub Profile

Let's Work Together

Ready to build something amazing? I'm always interested in discussing new opportunities, challenging projects, and innovative solutions in Java development.

Get In Touch

Currently Available

Open to new opportunities in backend development, microservices architecture, and distributed systems. Remote or hybrid positions preferred.

Why Choose Me?

6+
Years Experience
70%
Performance Boost
10K+
Daily Transactions
99.9%
System Uptime

Specializations

High-Performance Backend Systems
Microservices Architecture
Database Optimization
Distributed Systems & Caching

Response Time

I typically respond to inquiries within 24 hours. For urgent matters, feel free to reach out via Telegram.

Ready to Start a Project?

Let's discuss how I can help bring your ideas to life with robust, scalable Java solutions.

Send Me an Email