Вячеслав

Viacheslav Denysenko
Junior Java Developer | Java + AI / LLM Backend
[open contact info](look above in the "contact info" section) • [open contact info](look above in the "contact info" section) • Kyiv, Ukraine
github.com/slavikDe • t.me/slavik_denysenko

PROFESSIONAL SUMMARY
Junior Java Developer with a strong foundation in OOP, Java Core, and hands-on experience building web applications with
Spring Boot. Skilled in designing RESTful APIs, relational and NoSQL databases (PostgreSQL, SQL/NoSQL), and object-
relational mapping with Hibernate/JPA. Experienced with Docker containerization, Git version control, and Agile (Kanban)
delivery. Deeply focused on maintainable backend architecture and building orchestration systems for AI and Large
Language Models (LLMs). Fast learner seeking a production team where I can deliver business value and grow as an
engineer.

TECHNICAL SKILLS
Languages: Java 17 (Core, OOP, Multithreading, Streams, Collections), Python (basic), SQL
Frameworks: Spring Boot, Spring Core, Spring Data, Spring Security, Hibernate, JPA
Testing: JUnit, unit & integration testing
Databases: PostgreSQL, SQL, NoSQL, vector databases, object storage
API Development: RESTful APIs, REST, OpenAPI / Swagger, OpenAPI Generator, contract-first design, authentication &
authorization
DevOps & Tools: Docker, Docker Compose, Git, GitLab CI/CD, Maven, Gradle, Linux (Manjaro)
Architecture: Monolith, Microservices, Event-driven, Micromonolith, layered design
AI / LLM: LLM orchestration, AI agents, RAG (Retrieval-Augmented Generation), llama.cpp, Hugging Face models (Llama 3,
Qwen 2.5), server inference, context window management, tool selection
AI Tools: Claude Code, Codex, BMAD agent workflow, agent rules, skills, prompt engineering
CS Fundamentals: Data Structures (array, list, tree, map, hash), Algorithms (sorting, binary search, DFS, BFS, A*, D*, ant-
colony optimization), complexity analysis
Methodologies: Agile, Kanban, Atlassian (Jira)

WORK EXPERIENCE
Java Developer | WinWin Travel Oct 2025 – Present
● Contributed to the design and development of backend architecture for a travel platform using Java 17 and Spring
Boot.
● Developed clean, modular RESTful APIs for trip bookings, search filters, and user authentication using Spring
Security.
● Designed and documented API contracts with OpenAPI (Swagger); generated server stubs and client code via
OpenAPI Generator to keep the contract as the single source of truth.
● Implemented data persistence with Hibernate/JPA and PostgreSQL, applying object-relational mapping best
practices and query optimization.
● Applied AI agent tooling (Claude Code, BMAD agent workflow) to accelerate development, code review, and
requirement breakdown.
● Wrote unit and integration tests with JUnit to ensure API reliability and maintainability.
● Used Docker and Docker Compose to containerize services for consistent local development environments.
● Managed source control and code review through Git and GitLab, with CI/CD pipelines for automated builds and
testing.
● Collaborated in an Agile (Kanban) environment via Atlassian Jira to refine requirements and deliver features on
schedule.

PROJECTS
AI LLM Orchestrator | Diploma Project
gitlab.com/Thebestolo4b/orchestrator
● Engineered a modular backend orchestrator with Java 17 and Spring Boot to integrate and manage multiple Large
Language Models (LLMs).

● Implemented local server inference using llama.cpp with open models from Hugging Face (Llama 3, Qwen 2.5),
eliminating external API costs and ensuring data privacy.
● Built an advanced Retrieval-Augmented Generation (RAG) pipeline with hierarchical summarization for deep
semantic analysis of multimodal documents via vector databases.
● Designed a dynamic Tool Selector mechanism enabling the AI agent to choose and execute system tools or APIs
based on user intent.
● Containerized the full infrastructure (LLM servers, vector stores, object storage) with Docker Compose for
reproducible local development and deployment.

EDUCATION
B.Sc. in Software Engineering | Igor Sikorsky Kyiv Polytechnic Institute 2022 – 2026
Faculty of Informatics and Computer Science (FIOT) — Specialization 121, Software Engineering. Kyiv, Ukraine.

LANGUAGES
English — Upper-Intermediate (B2) Ukrainian — Native