Looking for a job

Eleanna Theo

@eleannatheo

Message

Full Stack Engineer at MyPay, migrating payments to Node.js/TypeScript and building fintech services.

Greece

Message

At MyPay S.A., I’m leading the migration of a legacy fintech platform for payments, money transfers, bill payments, and card issuing to a Node.js/TypeScript backend. I own backend services across card acquiring and merchant settlement, and implement OAuth2/JWT authorization and type-safe REST APIs.

At Reydix GmbH, I developed backend microservices for a fan-based event, artist, and venue management platform. I worked on Kafka integrations and Keycloak authentication, applying CQRS and DDD to features including Streaks and Achievements.

At MAS S.A./I4 Energy, I designed backend APIs and microservices for energy management and built React/TypeScript interfaces. My diploma thesis, Eye Tracking System (ETS), was a real-time reading assistant that adapted translation to gaze data and led to a peer-reviewed publication.

Experience

Work history, roles, and key accomplishments

Current

Full Stack Engineer

Current

MyPay S.A.

Jan 2026 - Present (9 months)

Lead the migration of a legacy payments platform to a modern Node.js/TypeScript backend, and own backend services for card acquiring and merchant settlement. Also hold technical ownership of client-facing web and mobile applications.

NodeJS TypeScript PostgreSQL Prisma React Capacitor OAuth JWT OpenAPI CI CD

Backend Engineer

Reydix GmbH

Jun 2025 - Dec 2025 (6 months)

Maintained and developed backend microservices for a fan-based event platform, designed event-driven integrations with Kafka, and applied CQRS and DDD principles to business features.

NodeJS Fastify Knex NestJS Prisma PostgreSQL Kafka Keycloak Kubernetes GitOps CQRS DDD

Backend Engineer

MAS S.A./I4 Energy

Dec 2023 - May 2025 (1 year 5 months)

Designed, developed, and maintained APIs and microservices for an energy management platform, optimized data interactions with SQL, MongoDB, and Elasticsearch, and integrated Kafka and MQTT for messaging.

TypeScript Deno Oak TypeORM SQL MongoDB Elasticsearch Kafka MQTT

Frontend Engineer

MAS S.A./I4 Energy

Mar 2022 - Dec 2023 (1 year 9 months)

Built and maintained complex React/TypeScript interfaces for an energy management platform, using Material UI, Redux, and Redux Toolkit for state management, and integrated RESTful APIs.

React TypeScript Material UI Redux Redux toolkit REST APIs Babel Webpack NPM JWT

Education

Degrees, certifications, and relevant coursework

University of Patras

Master's Degree, Computer Engineering and Informatics

2016 - 2024

Master's degree in Computer Engineering and Informatics, with majors in Applications and Foundations of Computer Science, Computer Logic, and Computer Hardware and Architecture.