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Valerii Kurnykov
Principal Java Developer
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Summary
Principal Java Developer with experience delivering software from legacy modernization to
greenfield production systems. Strong problem-solving skills and proven ability to drive
projects from idea to successful production release. Experienced in Spring Boot
microservices, Kafka-based integrations, security architecture, and technical leadership.
Strong background in customer communication, mentoring, and driving projects from
requirements to production.

Technical Skills
Languages Java, Kotlin, JavaScript, TypeScript
Backend & Web Spring Boot, Spring Data JPA, Spring Security, Spring WebFlux,
Hibernate, Redis, Ehcache, Jackson, Lombok, MapStruct, Protobuf, JSP, Servlet, HTML,
CSS, Thymeleaf, Apache Tiles, Jasper, iText, Netty, Apache Tomcat, OpenAPI/Swagger
Databases PostgreSQL, Oracle, MySQL, MariaDB, MongoDB, Couchbase
Testing JUnit, Mockito, PowerMock, WireMock
Messaging Kafka, RabbitMQ
Cloud/DevOps AWS, Azure, Docker, Kubernetes, Jenkins, Bamboo, Linux
Monitoring/ProfilingNew Relic, Java Flight Recorder, VisualVM, Prometheus, Grafana,
Elasticsearch, Logstash, Kibana
AI Tools Claude Code, OpenAI Codex, GitHub Copilot, AI-assisted Code
Review, AI-assisted Jira Search, Meeting Transcription & Analysis
Tools & Utilities Git, GitHub, GitLab, Maven, Gradle, Liquibase, Flyway, Jira,
Confluence, Bitbucket, Crucible, Lucidchart
Architecture Microservices, System Design, API Design, Event-driven Architecture,
Security Architecture
Spoken Languages English (C1), Ukrainian (Native), Russian (Fluent)

Professional Experience
Principal Java Developer, Friendly Tech | May 2022 – Present
Domains: IoT
Designed and developed a new Java and Angular-based administration platform from
scratch, replacing the legacy .NET solution and integrating it with the existing IoT backend
service through Kafka. Defined security and database architecture decisions. Designed and
implemented flexible authentication and authorization using Spring Security, supporting
internal databases, LDAP, and Active Directory integrations. Implemented JWT-based
authentication and fine-grained role-based access control. Built the application with support
for both Oracle and PostgreSQL databases. Collaborated with customers through business
analysts, mentored developers, and introduced AI tools into development workflows for code
review, Jira search, meeting analysis, and customer support chatbots.

Senior Java Developer, Etecture | January 2018 – May 2022
Domains: Telecommunications, Automotive, IoT
Worked on multiple projects across telecommunications, automotive, and IoT domains.
Contributed to large-scale microservice ecosystems using Spring Boot, Kafka, and Kotlin, as
well as smaller customer solutions delivered from scratch. Split legacy Java EE monolith into
7 Spring Boot microservices, reducing deployment time from 15 to 2 minutes and enabling
independent releases. Refactored complex SQL joins, introduced pagination and caching,
reducing API response time from ~900ms to under 200ms on key endpoints. Mentored 2
junior developers, reviewed onboarding projects.

Java Lead, Docomo Digital | January 2017 – January 2018
Domains: Telecom, Mobile Payments
Led backend development for integrations between mobile network operators and a digital
payments platform. Designed API integrations and data flow diagrams, collaborated with
cross-functional teams, and coordinated releases across multiple environments. Participated
in troubleshooting, performance analysis, and production support. Worked closely with
customers and stakeholders, gathering requirements and demonstrating delivered solutions.

Senior Java Developer, Luxoft | January 2016 – January 2017
Domains: Academic Publishing
Worked on a scientific publications platform, improving performance and stability of an
existing legacy system. Optimized SQL queries, resolved production issues, stabilized
automated tests and CI pipelines, and contributed to modernization of the legacy user
interface and user experience.

Java Developer, Itera | November 2012 – January 2016
Domains: Insurance & Financial Services
Worked on insurance projects, maintaining and extending existing codebases and resolving
production issues. Developed new services from scratch and created reusable project
skeletons to accelerate development and integration. Delivered production-ready features,
maintained legacy systems and mentored junior developers and interns in Agile teams.

C++ Developer, ALLIT Service | February 2012 – November 2012
Domains: Cybersecurity & Antivirus Software
Participated in development of antivirus software components for malware detection and file
analysis. Developed supporting tools and automated tests, contributing to software quality
and reliability. Maintained and enhanced existing components of the cybersecurity product.

C++ Developer Intern, GlobalLogic | October 2011 – February 2012
Domains: Digital Forensics & Law Enforcement Systems
Worked on a digital forensics system used by U.S. law enforcement agencies for searching
and analyzing information on storage devices. Implemented file indexing and search
functionality.

Education
Master’s Degree in Computer Science

Igor Sikorsky Kyiv Polytechnic Institute | 2006–2011

Focus Areas: Software Engineering, Programming, Algorithms, and Cryptography