gl.aser software & gestaltung

Senior Ruby & Linux/DevOps consultant (part-time, since November 2022): modernizing the entire legacy platform — mobile API and web apps — from its 2014/15 state to current technology, cutting operating costs and creating the basis for new product features.

• Strategic advice for CTO and Head of Product on aligning the tech stack with the product vision
• Comprehensive system upgrade: Linux, Ruby, Rails, nodeJS, MongoDB — adapting code and tooling for development, build and deployment; introducing infrastructure as code.
• Ported an app from Sinatra to Ruby on Rails with extensive refactoring, new tests, and much better UX for internal users (customer service, shipping, admins, research)
• Introduced a container-based development environment and deploy workflow with HashiCorp Nomad: deploy downtime reduced from hours to zero
• Markedly simpler system architecture and performance optimization, with measurable hosting cost savings

Ruby on Rails 3 → 7 · Sinatra · MongoDB 2 → 6 · nodeJS · Typescript · Hotwire · TailwindCSS · Redis · Docker · LXC · Nomad · Ansible · Prometheus · Grafana

Lead developer (June 2021 – May 2022) for the ground-up development of a web app physicians use to record treatment and medication data of hemophilia patients and report it to the German Hemophilia Register (DHR) — connected to an internal JSON API and the DHR’s Adjumed SOAP API.

• Technical lead of a team of 4–6 developers
• Advised the client on key aspects of the product concept and UX; designed the architecture and the data model
• Built critical components, including a SOAP API client with 2FA via IMAP
• Data management and data protection to medical-device standards ISO 13485:2016 and ISO 27000

Ruby 3 · Rails 6/7 · PostgreSQL · Redis · Sidekiq · JSON & SOAP APIs · IMAP · Hotwire · RSpec · Feature Flags · Docker · CircleCI · AWS · Figma

From senior Rails developer to technical product manager to interim CTO (jointly with the head of the infrastructure team) — including regular board meetings and technical interviews for CTO candidates.

• Technical leadership for up to 25 developers; hiring and onboarding of developers and product managers
• Drove the transition from a monolithic to a service-based architecture; long-term refactoring for performance at architecture and developer level
• Payment integration via Adyen for pay-ins and payouts in multiple currencies; GetYourGuide REST APIs
• Deep refactoring of the pricing model — preventing bugs and enabling A/B tests and new marketing features
• Compliance: GDPR implementation, extended KYC for payout recipients
• Introduced an internal RFC process (inspired by EmberJS & Rust) to improve the decision-making culture

Ruby on Rails 4/5 · MySQL · ElasticSearch · Redis · Sidekiq · ReactJS · RSpec · Capybara · A/B testing · Docker · Chef · Terraform · AWS