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Roman
DENYSIUK
Java Backend Developer

CONTACT ME SUMMARY
I am a Java Backend Developer with commercial experience in
[open contact info](look above in the "contact info" section) business automation, backend integrations, and AI-assisted workflow
[open contact info](look above in the "contact info" section)
[open contact info](look above in the "contact info" section) analysis. I build Spring Boot services, REST APIs, SQL-based backend
[open contact info](look above in the "contact info" section)
[open contact info](look above in the "contact info" section)
@DenysiukRoman logic, and integrations with external systems such as Telegram, CRM
@DenysiukRoman
github.com/roman680
@DenysiukRoman platforms, and 1C services. My recent work includes internal
Roman Denysiuk
github.com/roman680
roman680
automation services for FOP tax/payment workflows and CRM invoice
Warsaw
Roman
automation, where I helped turn manual business processes into
Roman Denysiuk
Denysiuk
structured backend systems.
Warsaw
EDUCATION
Warsaw, ready to work COMMERCIAL EXPERIENCE
both remotely and in
AI-Assisted Business Automation Developer
EDUCATION
office
PJAIT UT Service | 2026 - Present
Computer Science
2024 -EDUCATION
PJAIT present
Worked on internal automation services for payment, tax, CRM, and
Computer Science invoice workflows. Focused on backend development, process
Mate Academy
2024 - present
PJAIT automation, and third-party integrations. Analyzed workflow issues,
Java course
Computer science
2022 - 2023 clarified requirements, and translated them into clear technical tasks.
Mate
2024 Academy
- till now Tested changes, checked edge cases, and improved services used by
CS50
Java course
Programming
2022 2023 Basics
-academy internal teams to reduce manual work.
Mate
2020
Java
CS50course PROJECTS
2022 - 2023
COREBasics
Programming SKILLS TaxService — FOP Tax & Payment Automation Service
2020 Java 21, Spring Boot, JPA, PostgreSQL, React, TypeScript, Docker, Telegram Bot API,
CS50 REST API
Java 8+, Spring Boot, Rest API
Programming Basics Built a full-stack internal automation application for FOP tax/payment
Hibernate, JPA
2020 CORE SKILLS
Servlets, Tomcat, JDBC workflows, including an admin panel, FOP registry, bank operation
SQL, MySQL, PostgreSQL
Java 8+, Spring MVC/Security/Boot import, configurable tax settings, workflow status management,
Git, GitHub, CI/CD reminders, audit logging, and Telegram notifications.
Hibernate, JPA
SOLID, DRY SKILLS
principles
Servlets, Tomcat, JDBC CineWave - Cinema Management Web Application
OOP, Design patterns
SQL, MySQL Java 17, Spring MVC, Spring Security, Hibernate, MySQL, Maven
JUnit, Mockito, Spring Boot Test
Java
C++,8+, Servlets, Tomcat, JDBC
CMake
Docker, Liquibase
Built a cinema web application with movie sessions, shopping cart,
SOLID,MVC/Security/Boot
Spring DRY principles
Swagger/OpenAPI, Postman orders, and user/admin roles. Implemented authentication,
OOP, Design
Agile, Scrum,
Hibernate, patterns
JiraJUnit
JPA, authorization, CRUD operations, and database access using Spring
TDD, unit
Claude testing
Code (JUnit, Mockito)
and subagents Security and Hibernate.
OOP, Design patterns
Data
Git, GitHub,
structures
Maven
& algorithms GeoIP service
TDD, SOLID, DRY principles
A RESTful GeoIP Web Service implemented using Spring Boot,
LANGUAGES
Git/Github, Maven, ChromeDevTools
LANGUAGES Java 17, and Maven. The service allows users to get geographic
HTML, CSS information of an IP address by querying a database (MySQL) that
English: Advanced C1 (IELTS)
English: Advanced C1 (IELTS) contains data imported from IP2Location database. The service
English: Advanced C1 (IELTS)
Polish: Elementary A2
Polish: Elementary A1
Ukrainian:
Ukrainian:Native
Native provides information like city name, country code, country name,
Ukrainian: Native
latitude, and longitude based on a given IP address.