Open to full-time remote roles

Backend systems that keep running while they change.

I'm a Senior Java Backend Engineer with 5+ years building enterprise microservices on Spring Boot, Kafka, Oracle and PostgreSQL. I take legacy platforms apart and put them back together faster, safer and easier to maintain.

Get in touch GitHub ↗

topic career.nikolai-petkopartition 0

02018MSc, Mechanical EngineeringNovosibirsk State Technical University

12020-11switched to Javafirst apps: REST clients, online store

22021-07Java DeveloperInformation Systems and Services

32023-09Senior Java DeveloperSmart Design · telecom platform

4nownext role: remote, long-term

Tbilisi · UTC+4consumer lag: 0

Selected work

What I've shipped

Production systems for telecom and public-sector clients, where downtime costs real customers and every change has to roll out without breaking what already works.

Smart Design · 2023 – now

Monolith to microservices for a telecom client platform

+40%system performance after the migration

Led the move of a monolithic Oracle-based system to Spring Boot microservices talking over Kafka. Guided a team of two developers through the migration while the platform stayed in production.

Spring BootKafkaOracleDocker

beforeone Oracle monolith, one deploy for everything

accountsbillingadmin

kafka · events between services

Smart Design

One sign-in for 15+ microservices

15+services secured with zero downtime during rollout

Designed authentication and fine-grained access control with Keycloak and Spring Security across the whole platform.

KeycloakSpring SecurityOAuth 2.0

Information Systems and Services · 2021 – 2023

A social-services portal people rely on daily

45→80%test coverage, for a portal with 1,000+ daily users

Refactored 8 legacy modules and cut response time by 25%. Led a high-priority project from stakeholders to developers and launched it in two months.

LiferayJUnitJava

Stack

Tools I use every day

Modern Java on the JVM, from Java 8 codebases I've modernized to Java 21 services I've written from scratch.

Language

Java 8–21
SQL

Frameworks

Spring Boot
Spring Security
Spring Data JPA, Hibernate

Architecture

Microservices
Event-driven systems
REST APIs

Data & messaging

Apache Kafka
PostgreSQL
Oracle

Security

Keycloak
OAuth 2.0 / JWT

Delivery

Docker
Jenkins CI/CD
Maven, Git

Experience

Where I've worked

Engineer by training: a master's in mechanical engineering taught me to think in systems and failure modes before I wrote my first line of Java.

Sep 2023 – nowSmart Design

Senior Java Developer

High-load microservices platform for telecom client management, with configurable admin and user features.

Architected and led the migration from an Oracle monolith to microservices, improving performance by 40%.
Designed Keycloak-based authentication and access control across 15+ services.
Led two developers through the migration; mentor juniors through code reviews and pair programming.

Jul 2021 – Sep 2023Information Systems and Services

Java Developer

Liferay-based applications giving citizens online access to social services.

Built and optimized a portal serving 1,000+ daily users; raised JUnit coverage from 45% to 80%.
Refactored 8 legacy modules, cutting response time by 25%.
Chose the stack for a new project and coordinated stakeholders, analysts and developers to launch in two months.

2012 – 2018Novosibirsk State Technical University

Master's Degree, Mechanical Engineering

Moved into software in 2020 through self-directed backend training and production-style Java projects.

Contact

Let's talk about your backend.

I'm looking for a long-term, full-time remote role as a Senior Java or Backend Engineer, ideally with an employment contract (direct or via EOR).

Email: de.klaus.petko@gmail.com
GitHub: github.com/De-Klaus
Location: Tbilisi, Georgia
Time zone: UTC+4 · overlaps with European hours
Looking for: Full-time, remote, Senior Java / Backend