Nikos Kougianos

About

Java enthusiast with a B.Sc. in Computer Science and a M.Sc. in Data Science, bringing over 8 years of professional experience in software development.

For the past 4 years, I have gained deep expertise in the iGaming industry and microservice-based architectures, specializing in creating scalable, efficient applications that drive organizational success.

Basic Info

Email:

nkougian@outlook.com

Location:

Greece

Languages:

Greek, English

Professional Experience:

Personal Projects

Velocity RGS - Java

An audit-grade iGaming slot platform built as a deterministic Remote Gaming Server (Java 21, Spring Boot 3.x, Postgres & Redis), featuring:
- Server-authoritative spin outcomes with deterministic, bit-exact round replay from persisted RNG draws
- Idempotent mutations and session versioning to guarantee transactional integrity under retries
- Strict session FSM, BigDecimal money safety and in-memory JWT auth
- Three fully playable 20-payline slots with Free Spins, Power Bet, Bonus Buy and Pick & Collect features

Threedice: A dice betting game - Java

Full-stack Spring Boot application featuring:
- Idempotent Bet Placement
- Pessimistic Locking on Balance
- Transactional Integrity
- Integration Tests with Deterministic Dice (Testcontainers + REST Assured)

Spring Boot & Angular playground - Java/Angular

Full-stack Spring Boot and Angular application featuring:
- JWT-based authentication system with user management and role-based access control
- WebSocket integration for live chat functionality with user connection tracking
- External API integration (Disney API, DigitalOcean Status, UK Bank Holidays) with intelligent caching
- Kafka event streaming for cache analytics and audit trails
- MongoDB integration for persistent data storage with rate limiting and performance monitoring
- Advanced Redis caching with real-time analytics and cache-aside pattern implementation

Rest Api Aggregator - Java

Spring boot service with the following functionalities:
- Integrate with 3 REST APIs and dynamically combine the responses into 1, depending on the client's requested parameters
- Implement request throttling and batching of individual requests, using BlockingQueues.
- Create a scheduler that periodically checks items left in queues, and returns a response to the caller, guaranteeing a 10-second SLA

Carly Marketplace - Java

2 Spring Boot microservices powering a car marketplace, featuring:
- Role Based Access Control (RBAC) with Spring Security and an ADMIN > USER > FREE role hierarchy
- Persistence on a cloud MongoDB Atlas cluster (users, cars, roles & transactions)
- Asynchronous messaging via Apache Kafka on the cloud (Cloudkarafka)

Phonevice - PHP

This project offers a personalized smartphone recommendation based on 3 simple steps. Budget, features and types of use. An advanced recommendation algorithm takes place under the hood, that will always suggest the top 3 smartphones on the results page.

Data Science Thesis - Python

CLI application developed with Python, applying Supervised & Unsupervised ML Algorithms on a predefined dataset containing building energy features. The results from the algorithm executions are persisted on a cloud MongoDB cluster.

This project was developed in terms of my M.Sc. in Data Science.

Advanced Decision Making - Python

Python CLI application that applies Gaussian Naive Bayes and Multiple Linear Regression supervised algorithms and predicting with excellent accuracy student grades based on their social, family and other characteristics.

Work Experience

Java Team Lead - Full Time Contract

April 2025 - Present

Playnetic (Casino Dpt.) | United Kingdom (Remote)

Led a team of 5 developers, working with Product and C-level to turn business goals into actionable sprints.
Owned the core slot engine, building game simulation logic to verify RTP and shipping features like Power Bet, Feature Buy and Free Spins.
Maintained high-performance RGS services with ultra-low latency, session finalization and compliance for regulated markets (MGA, Italy, Greece).

Stack:
Java 21, Spring Boot 3, Apache Kafka, Redis, Cassandra DB, PostgreSQL

Senior Software Engineer (Java) - Full Time Contract

August 2022 - April 2025

BVGroup (Gaming/Casino Dpt.) | Gibraltar (Remote)
https://betvictor.com

Boosted marketing tool performance by 30% through optimization and seamless third-party API integrations.
Refactored the promotions platform from fragmented systems into a unified UI, cutting complexity and operator friction.
Built fault-tolerant, reactive microservices (Spring Webflux, Kafka) for third-party game provider integrations handling auth, launches and real-time transactions.

Stack:
Java 21, Spring Boot 3, Apache Kafka, Redis, MongoDB, Spring Reactive (Webflux), Junit5 (Mockito), testcontainers, Karate (BDD), GCP, Javascript

Lead Engineer (Java) - 3 Month Contract

July 2024 - September 2024

Khantech (Casino & Sportsbook) | Dubai (Remote)

Architected core wallet and backend systems from scratch including transaction/player history, session-based BetSlips, and comprehensive Casino API.
Led end-to-end integrations with TimelessTech (casino) and Betby (sportsbook) for seamless game launches and real-time transactions.
Designed event-driven architecture with Kafka enabling asynchronous, scalable microservice communication.

Stack:
Java 21, Spring Boot 3, Apache Kafka, Redis, MongoDB, Spring Reactive (Webflux), Kubernetes

Software Engineer (Java) - Full Time

January 2022 - August 2022

Atos | Athens, Greece (Remote)
https://atos.net

Delivered microservices-based Healthcare Interoperability platform serving multiple healthcare clients with FHIR compliance.
Optimized database performance by 40% implementing async multithreaded lookups using Spring's async capabilities.
Built Role-Based Access Control (RBAC) system with Spring Security, JWT token generation, and secure authentication.

Stack:
Java 17, Spring Boot, Maven, Microsoft Azure, PostgreSQL, Junit, Mockito, RestAssured, HAPI-FHIR (server & java client)

Software Engineer (Java) - Full Time

July 2019 - January 2022

Hellenic Telecommunications Organization S.A. | Athens, Greece
https://cosmote.gr

Built scalable microservices for internal Communication Hub transmitting 1M+ daily SMS/Email/Push notifications.
Engineered microservices integration layer enabling seamless communication between disparate internal systems.
Led Agile Transformation initiative as founding member of first Scrum team, coordinating cross-functional backend teams.

Stack:
Java 11, Spring Boot, Maven, Kubernetes, Jenkins, MongoDB, Apache Kafka, Junit, Kibana, Grafana

Lead Engineer (PHP) - Contract

June 2019 - March 2020

Phonevice | Athens, Greece (Remote)
https://phonevice.com

Built full-stack platform from ground up with custom recommendation engine and modern UI/UX.
Architected backend system and mentored team on best practices, coding standards, and design patterns.
Migrated Python algorithms to production PHP backend translating complex business logic into scalable system.
Developed partner REST API enabling third-party integrations and B2B partnerships.

Technologies/Tools used:
PHP 7, Bootstrap 4, Jquery, PHP Smarty Template, MongoDB, Python 3, Git, Bash, Microsoft Azure

Full Stack Engineer (PHP) - Full Time

November 2018 - May 2019

Figame LTD | Athens, Greece
https://figame.gr

Integrated Expedia and Booking.com APIs delivering new travel services to main site and affiliate network.
Reduced flight search response time by 80% implementing parallel search with PHP MultiCurl, dramatically improving UX.

Stack:
PHP 7, Bootstrap 4, jQuery, MongoDB, MySQL, SVN, Bash

Education