Hire the Best Spring Cloud 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 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 Frontend: CSS/HTML, JavaScript 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.

👋 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

Freelance IT Specialist | Software Engineer Delivering innovative, high-performance systems for over 17 years. I'm focused on complex system development, I’ve built scalable, resilient solutions for both B2C and B2B environments. Specializing in Java, Spring Boot, Spring Cloud, Maven, PostgreSQL, MySQL, Cassandra, MongoDB, RabbitMQ, and Azure Service Bus, I also bring expertise in technologies like Docker, Dropwizard, Kafka, Zookeeper, AWS. I design architectures that handle evolving demands with ease, integrating third-party systems seamlessly. I know how to design and implement complex systems from scratch, and I excel at supporting and revamping existing (legacy) systems to breathe new life into them. I’m always eager to explore and research new software, evaluating it for potential use in optimizing solutions and driving innovation. A few things I value: Collaborative mindset: I thrive in team environments where communication, trust, and shared goals drive the project forward. My leadership style is about guiding and sharing knowledge, not controlling - empowering teams to innovate while staying focused on delivering results. Precision: I’m committed to delivering clean, maintainable code with robust documentation. From Javadocs to Confluence pages, I ensure clarity so that my work remains accessible and easy to evolve. Every part of the system is documented, covering CI/CD setups and module-specific details. Testing is my backbone: Quality control isn’t an afterthought - it’s built into every stage of development. My philosophy extends beyond unit tests, incorporating performance testing to ensure scalability under real-world conditions. Eternal learner and innovator: Technology doesn’t stand still, and neither do I. I’m constantly exploring new methodologies, frameworks, and ideas to bring fresh insights to my work. From AI-driven automation to future-proofing system architectures, I’m always on the lookout for ways to elevate what’s possible. Freelancer with passion: As a freelancer, every project excites me like it’s my first. I thrive in fast-moving environments and love collaborating with teams to create software that not only meets immediate needs but anticipates future challenges. I’m committed to delivering innovations that matter and clean code that future developers will thank me for. What sets me apart? I bring a holistic approach, ensuring systems are not just functional but scalable, adaptable, and maintainable. From designing complex microservice architectures to ensuring third-party integrations are seamless, I focus on building systems that deliver real, lasting impact. More than just code, I care about the people and businesses behind the software. The right technology can make workflows smoother, interactions richer, and systems smarter - and I’m passionate about helping bring those transformations to life. If you’re searching for someone who combines deep technical expertise with a drive for innovation and quality, I’m ready to partner with you to build the future. Let’s create something remarkable together. P.S. If you’ve made it to this line, the very end of this long read, just tell me and I’ll give you a discount for your patience!

I'm a Java engineer in love with the craft and ambitious and humble enough to keep learning every step of the way. Open to projects of any size, easy-going and flexible. My goal is to deliver clean and maintainable code right on time and grow professionally over the years to come. I'm sure we'll find a common language, you'll definitely be happy to see the tasks done right on time. A technical assessment or an iterview is always fine by me. My main tech stack: - Java8+ (Core) - Spring Framework (Core, WEB, AOP, Reactive) - Spring Security (Authentication, Authorization, OAuth2, JWT,Form Auth) - Spring Boot (Properties/YAML, Actuator) - Rest API bestpractice - SQL (MySQL, PostgreSQL) - NoSQL (MongoDB, FaunaDB, DynamoDB) - Spring Data (JPA, Hibernate, JDBC, R2DBC, MongoDB, ElasticRepository) - ElasticSearch - Spring Cloud (Cloud Gateway, Cloud Config, Cloud Circuit Breaker, Cloud OpenFeign, Eureka service registry) - Microservices - Microservice Patterns (Aggregator, Event Sourcing) - DevOps (Docker, Docker-compose) - AWS (S3, Lamda, Serverless, DynamoDB) - WebFlux - Message Queues (Kafka) - Testing (JUnit 4, JUnit 5, MockMVC, JpaTest, Testing Services, Fake patterns)

Greetings, I am a software engineer/architect from Lviv, Ukraine, with 15 years of experience. Google Cloud Professional Architect certified. Strong knowledge of SDLC and project execution stages: requirements gathering, feature planning, estimation, design and implementation, product maintenance, DevOps, and CI operations. Proven track record working with diverse clients ranging from small startups to Fortune 500 companies ✅Excellent knowledge of Java/Spring & Spring Boot/Hibernate/MySQL/Docker ✅Certifications: Google Cloud Architect Professional, Spring Certified Professional (by Pivotal)., Azure Fundamentals(AZ-900) by Microsoft ✅Strong knowledge of GCP/AWS/Azure platforms and cloud-related technologies. ✅TDD practitioner Feel free to ping me in order to discover how can I help solve your IT issues