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Babiuk Oleksandr Java backend developer

CONTACT Phone: [open contact info](look above in the "contact info" section) Address: Lviv, Ukraine
Email: [open contact info](look above in the "contact info" section) linkedin: OleksandrBabiuk

WORK EXPERIENCE

Fin Plus Plus
System Administrator L1 | 02/2025 - 07/2025
Administered IT infrastructure for -50 users
Monitored and troubleshooted local network issues
Reassembled and maintained servers and network switches
WinWinTravel
Java backend developer | 10/2025 - now
Developed unit and integration tests for backend services using JUnit, Mockito, Spring Boot Test.
Identified and fixed multiple logical and business-flow bugs in existing services.
Worked with Redis (caching, TTL, consistency checks) to improve performance and stability.
Worked with Apache Kafka for event-driven communication between services.
Improved service reliability and data consistency through testing and bug fixing.

EDUCATION

Lviv Polytechnic National University | 2022 - now
Barchelor's degree, Computer Science

Education & Academic Experience
Studied Computer Science / Software Engineering with hands-on experience in C, C++, Python, Java, Web
technologies, Linux, and Bash.
Developed embedded software in C for ESP32 microcontrollers, working with low-level logic and hardware
interaction.
Built a desktop application in C++ using Qt with database integration.
Developed a web platform for journalists using React (frontend), focusing on UI.
Studied Machine Learning and Data Science using Python.
Implemented and trained deep learning models including CNN, RNN, LSTM, ART, GAN, TrOCR, SOM.
Built and fine-tuned a TrOCR-based model for handwritten text recognition, including data preprocessing,
training, and evaluation.
SKILLS

Programming Languages: Java, Python, JavaScript, C, C++, SQL
Backend & Frameworks: Spring Framework (Spring Boot, Spring Data JPA, Spring Security), Hibernate
(JPA), RESTful API, RPC
Databases & Migrations: MySQL, MongoDB, Liquibase, Flyway
Testing: JUnit 5, Mockito, Integration Testing
Concurrency: Java Multithreading
Messaging & Caching: Kafka, Redis
Security: JWT, Spring Security
DevOps & Build Tools: Git, Maven, Docker
Operating Systems & Scripting: Windows, Linux, Bash
Frontend (Basic): HTML, CSS, JavaScript, React
Software Design Principles: OOP, SOLID, KISS, DRY

Side projects(Java based)

OCEIS
OCEIS is a startup project for the food service industry, co-founded with a colleague. The
project is currently in active development. My primary responsibility is the development of
the backend server using Spring Boot and Hibernate. I have implemented a secure REST API
with role-based access (admin and user), a custom permission system, and participated in
designing the system architecture and database schema. The system includes JWT-based
authentication, input validation, Liquibase database migrations, and is containerized using
Docker. I also created unit and integration tests with JUnit 5 and Mockito, and configured a
Cl/CD pipeline for automated building and deployment. Meanwhile, my teammates are
working on a React-based web client and a mobile application to interact with the backend.

Encoder
I developed a simple encoder with a JavaFX UI that can encode and decode text, including
support for different languages and reading from files.

GeoGenius
It was a university team project where I was responsible for backend development. I
implemented a REST API for a mobile client using Spring Boot and Hibernate (JPA). I
integrated Log4j for logging and used the Google Drive API to store user photos. To deploy
the service, I configured a public (white) IP address and set up global access without using
paid hosting provider.