Andrii

Andrii Tyvodar
Junior Java Backend Developer, Spring Boot, PostgreSQL
[відкрити контакти](див. вище в блоці «контактна інформація»), github.com/andrewtyv, [відкрити контакти](див. вище в блоці «контактна інформація») Bratislava, Slovakia,
[відкрити контакти](див. вище в блоці «контактна інформація»)

Summary
Junior Java Backend Developer with practical experience building REST APIs using Spring Boot, Spring Security,
PostgreSQL, JPA/Hibernate, Docker, and JWT authentication. Developed backend projects with real-time WebSocket
communication, role-based access control, OAuth login, file uploads, and API documentation. Currently completing a
Bachelor’s degree in Information Technology at Slovak University of Technology, with additional research experience
in side-channel security.

Technical Skills
Languages & Frameworks
• Java (OOP, Collections, Streams, Generics)
• Spring Boot, Spring Web, Spring Security, Spring Cloud
• Spring Data JPA / Hibernate
Backend & Infrastructure
• REST API design, JWT authentication, OAuth 2.0 / SSO
• WebSocket / STOMP, Microservices architecture
• PostgreSQL, relational schema design
• Docker, Maven, Git, Swagger, Postman
• Unit & integration testing: JUnit, Mockito
Research & Low-level
• Side-channel analysis, data leakage assessment, ARM Cortex-M, embedded systems
• Network protocols: ARP, Proxy ARP, DHCP, RIPv2, IP forwarding
• Static timing analysis, compiler optimization, statistical leakage testing (TVLA)

Professional Experience
Backend for Real-Time Mobile Platform 2025 – present
Java, Spring Boot, Spring Security, JWT, JPA/Hibernate, PostgreSQL, WebSocket, Docker
https://github.com/andrewtyv/StudyBoddyBack
• Designed and delivered a production-ready REST API with 58 endpoints across auth, users, chat rooms,
friendships, geolocation, blog, and settings — supporting a full mobile app feature set
• Implemented JWT-based authentication and multi-level role-based access control (TEACHER / STUDENT /
room roles: OWNER, ADMIN, MEMBER), securing all endpoints with Spring Security
• Built real-time messaging with WebSocket and STOMP protocol, enabling room-scoped broadcast topics with
low-latency delivery
• Integrated Google OAuth 2.0 SSO via GoogleIdTokenVerifier and push notifications via Expo Push API
• Implemented server-side geolocation distance calculation using the Haversine formula
• Designed normalized PostgreSQL schema covering users, friendships, chat rooms, messages, and student profiles;
managed with JPA/Hibernate
• Delivered file upload system for avatars and chat images with MIME type validation and filesystem storage
• Achieved 95% instruction coverage and 85% branch coverage across all controllers (JaCoCo); tested with
JUnit 5 and Mockito
• Documented full API with Swagger (OpenAPI 3.0) and validated all flows with Postman
• Containerized the full application stack with Docker for consistent deployment

Software Router 2024
Java, Spring Boot, multithreading, scheduler
https://github.com/andrewtyv/router
• Built a fully functional software router in Java from scratch, implementing ARP, Proxy ARP, DHCP, RIPv2,
and IP forwarding without high-level libraries — demonstrating deep understanding of the networking stack
• Implemented ARP and Proxy ARP for hardware address resolution across network segments
• Developed a DHCP server for dynamic IP address assignment and lease management
• Implemented RIPv2 routing protocol with route advertisement, metric calculation, and convergence

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 • Built an IP forwarding engine with a routing table for packet forwarding decisions

Research Experience
Security Researcher — Side-Channel Analysis 2024 – present
Slovak University of Technology, FIIT
• Bachelor’s thesis: Leakage Assessment of Shuffled Neural Networks — analyzed information leakage at the
implementation level on ARM Cortex-M hardware — github.com/andrewtyv/leakage-aassesment
• Conducting ongoing research on constant-time implementations of activation functions to eliminate timing-based
leakage — github.com/andrewtyv/activation timing

Education
Slovak University of Technology (STU), FIIT 2022 – 2026
Bachelor in Information Technology
Relevant coursework: Algorithms & Data Structures, Computer Networks, Operating Systems, Cryptography, Blockchain

Teaching Experience
Private Mathematics Tutor part-time
• Tutored university students in calculus and complex analysis, improving their exam performance
• Developed strong ability to communicate complex technical concepts clearly

Languages
English — B2, Slovak — B2, Ukrainian — Native

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