Roman

HODULIAN ROMAN
TRAINEE JAVA DEVELOPER

CONTACT PROFILE

Motivated Junior Java Backend Developer with experience in Java, Spring
[відкрити контакти](див. вище в блоці «контактна інформація»)
Follytt Boot, Vespa, and working with databases. Strong knowledge of OOP and

LinkedIn data structures.

Github

EDUCATION
WORK EXPERIENCE
2022 - 2026
ODESSA POLYTECHNIC NATIONAL Self-employed 2025 - PRESENT
UNIVERSITY, ODESA Developer

Software Engineering (121) I am currently actively expanding my horizons in Java programming,
progressively learning Spring Boot, putting theory into practice in my own

2019 - 2022 pet-projects, and improving my fundamental knowledge on Leetcode.
ODESSA VOCATIONAL COLLEGE OF I am currently developing two pet-projects: one focused on data handling,
COMPUTER TECHNOLOGIES, ODESA
and the other on the Spring Security module, JWT tokens, and databases.
Business economics (051)
PROJECTS
SKILLS
Search engine 2025 - PRESENT
Java Core
Product Search Engine (Pet-project) — a product search system (50k → 1M
OOP
products) built on Vespa.
Spring Boot
It supports full-text search with the bm25 algorithm, filtering by product
Spring Security
attributes, and query execution via Postman. A custom module in Java
Vespa
(Vespa Searcher API) was implemented to expand queries using a synonym
Postman
dictionary: on startup, synonyms.json is loaded, normalized via Jackson
PostgreSQL
custom deserializers, and queries are rewritten with synonym groups in the
JSON
form (syn1 OR syn2 …) to improve relevance. To optimize performance, a
Maven
bidirectional map (canonical ↔ synonyms) with constant-time access was
Git
introduced. The project also includes SLF4J logging, robust error handling
Rest API
for data loading and parsing, and a well-documented product data schema.

LANGUAGES Vespa is a distributed, open-source cloud platform (developed by Yahoo!)
designed to serve large volumes of data and perform complex
English (B1)
search/ranking queries in real-time (low-latency).
Microservices Auth & Data Processing App 2025 - PRESENT
Development of two Spring Boot microservices (Service A: auth-api and
Service B: data-api) orchestrated using Docker Compose and PostgreSQL.
The project simulates a basic API Gateway that handles authentication and
redirects requests for processing.

Key Features Implemented:

Service A (auth-api): Implemented authentication (register/login) using
JWT and BCrypt password hashing. Acts as a gateway, accepting a
protected /api/process endpoint request.
Inter-Service Communication: Service A calls Service B (http://data-
api:8081/api/transform) using a secret header (X-Internal-Token) for
internal authorization.
Service B (data-api): Validates the presence and validity of the X-
Internal-Token and executes simple transformation logic on the input
text (e.g., reversal, uppercase conversion).
Request Logging: Service A saves a record in PostgreSQL (userId, input,
output, timestamp) for every processed request in the processing_log
table.
Infrastructure: The entire project is dockerized with a docker-
compose.yml file that starts both Spring Boot services and the
PostgreSQL container, configured using environment variables.