~$ whoami

Chrisovalantis
Efthymiou

Senior Software Engineer · Playtech

Python Oracle PL/SQL Distributed Systems Real-Time Feeds ETL Kubernetes

Backend engineer with 8+ years building and maintaining high-availability systems across online gaming and sports betting — lottery and betting platform components, time-sensitive data-feed services, and analytics pipelines.

Now shipping across lottery, real-time feeds & ETL — in parallel.

Get in touch LinkedIn ↗

years at Playtech

2.7→3.14

Python migration in prod

Jr→Sr

four levels, one team

Oracle→BigQuery

async ETL pipeline

Experience

Playtech

Nicosia, Cyprus · Jun 2018 – Present · 8+ years

Sports Betting & Lottery

Senior Software Engineer May 2026 – Present

Software Engineer II 2023 – 2026

Software Engineer I 2021 – 2023

Junior Software Engineer 2018 – 2021

Lottery & Betting Platform

Develop and maintain backend components of high-availability lottery and betting platforms in Python and Oracle PL/SQL, within a small engineering team.
As Senior, oversee platform backend work and mentor on design and code quality.

Python 2 → 3 Migration

Played a key role migrating the platform's large legacy codebase from Python 2.7 to 3.11 — identifying breaking changes, refactoring components, and keeping production stable throughout.
Continued the effort to Python 3.14, taking it to production with a smooth, incident-free rollout.

Real-Time Data Feeds

Built and maintain time-sensitive services processing external providers' data with Python and MongoDB, running on Docker and Kubernetes with Helm-managed deployments.

Data Warehouse ETL

Started with parallel SQL extraction from Oracle into Google BigQuery for analytics and reporting.
Redesigned the pipeline as an asynchronous Python service with an orchestrator–worker architecture.
Now improving it with data reconciliation between source and warehouse.

Skills

Languages

Python · Oracle PL/SQL · SQL · Java

Data & Storage

Oracle Database · MongoDB · Google BigQuery

Infrastructure

Docker · Kubernetes · Helm · Linux · Azure Functions · Azure Container Apps

APIs & Integrations

REST API integrations

Systems

Distributed systems · Real-time data feeds · ETL pipelines · High-availability services

AI-Assisted Development

Cursor for day-to-day engineering — reviews, refactors, feature work · Claude Code for personal projects, automation & prototyping

Education

MSc, Biomedical Engineering

Cyprus University of Technology

2018 – 2022 · 7.79/10

Minor, Biomedical Engineering

University of Cyprus

2017 – 2018 · 7.33/10

BSc, Computer Science

University of Cyprus · Thesis: comparative study of fitness APIs & a mobile app for fitness and health (9/10)

2013 – 2017 · 7.33/10

Google Hash Code — 1st Pancyprian, 299th Worldwide

Contact

Interested in working together?

Or just want to say hi — I'm easy to reach.

chrisovalantis@hotmail.com LinkedIn ↗ GitHub ↗

📍 Nicosia, Cyprus