Hire the Best Spring Boot Freelancers
in Ukraine

I deliver production-ready Java backends that scale. With 100% Job Success and $10K+ earned across 22 contracts, I solve complex integration challenges, refactor legacy systems, and build APIs that handle real-world traffic. Client Testimonials: "Oleksandr is a genuine professional who was able to do a complex Java project for me." – Sweet Home 3D Client "Fast developer, always in contact, reasonable price policy. Would work with him again." – Spring Boot Projects Client Proven Results: ✅ Sweet Home 3D Plugin – Delivered complex Java plugin modifications for long-term client ($2,345 total) ✅ Calendar Integrations – Built Microsoft & Google Calendar sync in Spring Boot (5.0★ rating) ✅ PostgreSQL Migration – Configured clinical trial database with 43 billable hours (5.0★ rating) ✅ Cron Jobs & Refactoring – Optimized Spring Boot scheduler logic ($440 fixed-price) What I Deliver: Spring Boot APIs – REST endpoints, authentication (Spring Security), database integration (JPA/Hibernate) Database Solutions – PostgreSQL schema design, query optimization, MongoDB aggregations Legacy Refactoring – Clean up messy code, introduce testing (JUnit/Mockito), containerize with Docker Third-Party Integrations – Payment gateways, calendar APIs, external data syncs Testing & Quality – Unit tests, integration tests, TestContainers for reliable deployments Tech Stack: Backend: Java (8/11/17/21), Spring Boot, Spring Data JPA, Spring Security, Hibernate Databases: PostgreSQL, MySQL, MongoDB APIs: REST, JSON/XML, Swagger/OpenAPI Testing: JUnit, Mockito, TestContainers DevOps: Docker, Kubernetes, Maven, Git Principles: OOP, SOLID, TDD, GOF Design Patterns Why Hire Me: ✔ Fast turnaround – Average response time: 0-4 hours ✔ Clear communication – Tagged "Clear Communicator" by 5 clients ✔ Proven reliability – Top Rated, 100% Job Success, no failed contracts ✔ Real-world experience – From startups to clinical trial systems Have a backend challenge? Let's architect a solution together. 📩 Send me your project details, and I'll respond with a technical approach within hours.

"Hi! 👋 I'm a backend developer with 3 years of experience specializing in Java ☕ and the Spring Framework 🌱. With a robust understanding of SQL 🗄️, REST 🌐, and various database systems, I’m dedicated to creating high-performance, scalable, and maintainable applications. 🚀 My expertise in testing 🧪 and deployment ensures that my solutions are functional and reliable." Technical Skills: 🟡 Programming Languages: Java 🌱 Spring Framework: Spring Boot, Spring Core, Spring Data Access, Spring Web, Spring MVC, Spring Security 📦 Object-Relational Mapping: Hibernate, JDBC, JPA, OXM ✅ Testing: JUnit, Jupiter, Mockito, Unit Tests, Integration Tests 🛠️ Build Tools: Maven 🗄️ Databases: SQL, MySQL, PostgreSQL 🔄 Version Control: Git 💻 IDEs: IntelliJ IDEA, Eclipse, Neovim 🔗 Other: Java OOP, Collections, Exception Handling, Streams and Lambdas, Concurrency and Multithreading, Input/Output (I/O), Memory Management, Design Patterns, Annotations. What I Offer: 🌐 Backend Development: Building RESTful APIs and microservices with Spring Boot, ensuring efficient data handling and service integration. 📊 Database Management: Designing and implementing robust database schemas and optimizing SQL queries for MySQL and PostgreSQL. 🧪 Testing Excellence: Writing comprehensive unit and integration tests to ensure code quality and functionality. ⏩ Agile Methodologies: Familiar with Agile practices, enabling rapid development and iterative feedback. 🤝 Collaboration: Strong communicator who thrives in team environments, working closely with front-end developers, product managers, and stakeholders. Why Work With Me? ✨ I am passionate about technology and continuously seek to improve my skills and stay updated with industry trends. My approach combines technical expertise with a commitment to delivering quality solutions that meet your business needs. I take pride in writing clean, efficient code and always look for ways to enhance performance and scalability. Let’s Connect! 🎉 If you’re looking for a dedicated backend Java developer who can deliver results, I’d love to discuss your project further. Feel free to reach out, and let’s create something amazing together!

👋 Hello! Senior Java Developer, Team Lead & Architect with 10+ years of hands-on experience with 10+ years of hands-on experience building scalable, high-load web and mobile applications. I mainly work with Java backend, JavaScript, TypeScript, Oracle, Postgres databases. My core backend work is centered on Spring Boot, focusing on API development and production-grade RESTful services backed by PostgreSQL. My focus is on backend software architecture, ensuring scalability, clean boundaries, and long-term maintainability. ✔️ Ready-to-Use Integrations I can accelerate your product using proven, production-ready integrations: 🚀 AI & LLMs: ChatGPT, LLaMA, Mistral (text, images, vision, automation) 🚀 Payments: Stripe (card payments & transfers) 🚀 Voice & Media: ElevenLabs (speech & voice AI) 🚀 Communication: Zoom (voice & video integrations) My Specialization: ✅ Backend & Architecture: Java (10+ years): modern Java (Lambdas, Streams, Date/Time API), Spring (9+ years): Spring Boot, Spring Data, Spring Cloud for microservices and distributed systems, and Java EE: REST APIs, SOAP, JPA, third-party integrations ✅ Security & Frameworks: Keycloak with OAuth2 and JWT-based authentication, JHipster, Swagger, Liquibase, Axon, Vaadin, ORM: Hibernate, Blaze-Persistence ✅ Databases & Messaging: SQL (10+ years): PostgreSQL, MySQL, MariaDB, Oracle, NoSQL: MongoDB, Redis, Hazelcast, Messaging: Kafka, ActiveMQ, RabbitMQ, Zookeeper, Firebase Messaging ✅ DevOps & Observability: CI/CD: Jenkins, Docker, Kubernetes, ELK Stack (Logstash, Elasticsearch, Kibana) ✅ Quality & Delivery: Testing: JUnit, Mockito, Spring Test, Unit & Integration testing, Full SDLC, code reviews, refactoring, clean architecture 💡 Let’s discuss how I can help you build a reliable, scalable solution!

I am a seasoned software developer with over 10 years of experience specializing in Backend and Full-Stack development. I pride myself on my excellent problem-solving skills and have a strong passion for writing clean and testable code. Clear communication is one of my strengths, making me a valuable team member in any software development project. Preferred Tech Stack: Backend: Java, Spring Boot, Thymeleaf, REST API, PostgreSQL, AWS, Linux, Tomcat, Nginx Frontend (Web): HTML, CSS, Sass, Javascript Frontend (Mobile): Flutter, Dart Cross-Platform: Flutter, Dart I am also proficient in the following technologies: Languages: Java, Scala, Groovy, Kotlin, Golang, JavaScript, TypeScript, Python, Dart, SQL Databases: PostgreSQL, MySQL, Oracle, Cassandra, MongoDB, SQLite, Neo4j Frameworks (Backend): Spring Boot, Spring Security, OpenAPI, Kafka, Zookeeper, Grails Frameworks (Frontend): Angular, React, Flutter, jQuery, Bootstrap Security: Spring Security, OAuth, JWT Technologies: HTML, CSS, JSON, XML, REST API API: REST API, OpenAPI, Swagger Messaging: Kafka, ActiveMQ, RabbitMQ Search: ElasticSearch, Lucene, Kibana Logging: ElasticSearch, Logstash, Kibana Cloud Providers: AWS, Google Cloud Testing: JUnit, Mockito, TestNG, Selenium, Cucumber, Katalon Studio Development Tools: Intellij IDEA, VSCode, Android Studio

📢 Available for new projects 📢 I'm a Senior Java Developer with more than 10 years of commercial experience building stable, scalable, and secure backend systems. I specialize in Spring Boot microservices and cloud-native architecture — and I've shipped production systems in Fintech, EdTech, Healthcare, Retail, Hospitality, etc. My core strength is backend architecture: clean APIs, event-driven systems, and services that scale. I also work across the full stack development when needed — React on the frontend, Node.js for integrations, and AWS for deployment and infrastructure. What I bring to your project: - Production-grade Spring Boot microservices and REST APIs - Cloud infrastructure on AWS with Docker and CI/CD pipelines - Full-stack capability: Java backend + React frontend - Relational and NoSQL databases: PostgreSQL, MySQL, MongoDB - Clean, maintainable code with TDD and Agile workflows I've worked on SaaS platforms, enterprise systems, and MVPs — from initial architecture through to deployment. Go-To Stack: Java (Spring Boot, Spring Cloud, Hibernate) · React · Node.js · AWS · Docker · PostgreSQL · MongoDB · Jenkins · GitFlow Ready to start - just drop me a message and we will start working!

I am passioned Java developer with almost 14 years of experince in building robust and scalable applications. Have experience working with some of the biggest clients in the industry, including Medhost, DHL, Inditex, Ladbrokes Coral... My core strength lies in designing and developing backend systems using Java and a diverse set of supporting technologies. My strong areas are: - dedicated to addressing complex business challenges through tailored programming solutions with a client-focused approach; - focus on developing highly scalable, low-latency, highly available, fault-tolerant, secure, and clean-code solutions; - quickly learn and apply new technologies, tools and frameworks; - strong focus on clean code and scalable architecture; - ability to explain technical decisions and concepts effectively to teams and stakeholders; - always strive to enhance both my technical and soft skills; Core Stack Programming Languages: Java (primary), JavaScript (secondary); Systems: monolithic and microservices-based; Frameworks: Spring, Spring Boot. UI: Angular, React Infrastructure: Docker, Kubernetes, AWS Databases: MySQL, DB2, MongoDB, PostgreSQL. Messaging & Caching: Kafka, Redis, RabbitMQ, ActiveMQ Build Tools: Maven, Gradle, Ant, Ivy. Version Control: Git, SVN. Development Tools: IntelliJ IDEA, Eclipse, and VS Code OS: Windows, Linux, macOS