Jan 2019 – Dec 2020 · 1 yr 11 mos

• Authored a distributed, horizontally-scalable Ruby test runner that parallelizes test suites among many workers using a queue. Reduced test suite execution time from 14+ hours to 8 minutes
• Implemented a caching build server in Go, reducing CI/CD build times by up to 3x
• Manage a team of 5 Software Engineers; participate in hiring, mentoring, 1-on-1s and working with Objectives and Key Results
• Operate 150+ production VMs in our on-premise infrastructure including provisioning, troubleshooting and upgrades

Aug 2016 – Jan 2019 · 2 yrs 5 mos

• Authored a file downloading service in Go, exposing a REST API and using Redis as the backing data store
• Incorporated Kafka into the stack by implementing a Kafka proxy in Go and a consumer framework for Ruby applications
• Introduced the Go programming language to the organization by rewriting a mission-critical microservice from Ruby to Go
• Implemented ChatOps; authored a Ruby library that allows to implement chat commands in Rails applications

Jan 2015 – Aug 2016 · 1 yr 7 mos

• Organized and upgraded the main monolith from Rails 3 to Rails 4 with zero downtime and development disruption to 60+ engineers
• Upgraded the main monolith from Ruby 1.9 to 2.1 with zero downtime. Performed benchmarks and created monitoring tools to ensure no performance regressions were introduced
• Became a member of the Bundler team after various contributions to both Bundler and Rubygems

Dec 2012 – Jan 2015 · 2 yrs 1 mo

• Designed and implemented user-facing features for the main web application (https://www.skroutz.gr)
• Created a solution for persisting and querying volatile user session data with a simple API, using Elasticsearch as the backing storage. Currently serves 7000 QPS
• Authored design documents and cooperated with non-technical colleagues for determining project requirements

Nov 2015 – Jul 2016 · 8 mos

• Developed a Laravel web application for conducting psychometric tests on military personnel
• Administered the Hellenic Army homepage (https://www.army.gr)

Jan 2015 – Jan 2017 · 2 yrs

• Implementation of an online store using Ruby on Rails and PostgreSQL
• Development of faceted search capabilities using Elasticsearch
• Optimized user experience by implementing caching techniques at various levels, using Nginx and memcached
• Provisioned and operated memcached, Nginx, PostgreSQL, Elasticsearch and Unicorn.
• Set up production deployment pipeline using Capistrano.

Sep 2006 – Feb 2011 · 4 yrs 5 mos · Thessaloniki, Greece

• Designed and developed static and dynamic websites for a wide range of clients using PHP and Ruby.