Nov 2021 – Aug 2024 · 2 yrs 9 mos · Athens, Attiki, Greece

• During my time at Blueground, I worked mainly on the website codebase, primarily on the server, with some involvement in frontend tasks using Vue. While I achieved many things in this role, I would highlight three key accomplishments:
• Runtime & Library Updates: Became the go-to person for managing and updating runtime environments and libraries, ensuring smooth transitions and maintaining system stability.
• Pricing Model Change: Implemented a new pricing model, ensuring it was integrated seamlessly without compromising the website’s speed or performance.
• Server Performance Optimization: Spearheaded performance improvements in backend code that resulted in a 30% to 50% reduction in response times for single requests and a 10x increase in requests per second (from 90 to 900) on the listings page (as indicated by Datadog).
• Technologies Used: JavaScript/TypeScript, Node.js, Vue 2/3, Redis, MongoDB/Atlas, RabbitMQ, Kafka, Docker

Jul 2020 – Nov 2021 · 1 yr 4 mos · Athens, Attiki, Greece

• Helping YOU to get food for your mood!
• Developed BOX back-end application
• During the first six months, apart from the development of new features I:
• refactored the server application leading to a bit more than 60% reduction in lines of code (120k to 47k), 43% less dependency volume (from 98,7 MB to 56,2 MB), a reliable application and developer satisfaction
• step-by-step upgraded node and dependencies 3 major versions, leading to less memory consumed (metrics of heroku on a 2x dyno during idle periods from ~350MB to ~170MB) and an overall more reliable application
• set up ESLint leading to IDE pinpointing errors, fixing of many covered bugs (when we first decided the rules which satisfied our needs, the whole project had around 12k errors. Now, the number has fallen to 1k and it goes down day by day
• revisit testing suite, fixed flaky tests, removed unused tests leading to a 100% deterministic test suite
• used the cluster module to scale application, leading to an average of less 2000$/month operational costs, while the average orders/week have doubled!
• am responsible for the training and on-boarding of every new member to the backend team, focusing on creating awesome engineers! (4 great junior engineers)

Oct 2018 – Jul 2020 · 1 yr 9 mos · Athens, Greece

• Worked in a scrum team of 9 people. The scrum master role is rotating among developers, thus, I served as scrum master, too.
• Developed tools to make insurance agents' lives easier.
• Tools are about:
• maintain Liferay portal
• managing workflow
• several portlets about compliance to international and local laws (ie. GDPR, PCI)
• issue health insurance applications
• alter health insurance policies

Jul 2018 – Sep 2018 · 2 mos · Athens, Greece

• Programming Languages & Respective Frameworks
• Java - Apache Wicket
• Groovy - Spock
• Software Development Methodology
• Test Driven Development - Pair Programming - Code Reviews (XP - Extreme Programming)
• Managing Work Framework
• Scrum (rotating Scrum Master role)

Dec 2016 – Dec 2017 · 1 yr · Piraeus, Greece

• Environmental Issues handling (i.e. compliance with ISO 14001, waste handling, law compliance)
• Quality Assurance Management System (transaction of ISO 9001:2008 to 9001:2015)
• Pre sales (Designing documents, presentations & videos)
• Marketing (i.e. Design of Business Cards, email signatures)
• Construction and maintenance of eShop database
• Testing possible pivoting scenarios (ISO 17025 calibration lab, Ballast water treatment system, explosiveproof certification -ATEX/IECEx- of corporate products, design of production line for Magnetostrictive Level Sensors)

Jul 2015 – Jun 2016 · 11 mos · Tripoli, Greece

• Military Duty, Commander Assistant Office

Sep 2011 – Jun 2013 · 1 yr 9 mos · Patras, Greece

• Helped many of my classmates pass the following courses in university:
• FORTRAN 90/95 for Chemical Engineers
• Advanced FORTRAN 90/95 for Chemical Engineers
• Numerical Analysis

May 2011 – Aug 2011 · 3 mos · Tripoli, Greece

• Study of Wastewater Treatment Plants of Tripoli, Astros & Vytina in Arcadia, Greece