Concept, advising, and implementation of fundamental system upgrades of the legacy software (mobile API, web apps) as of 2014/15 to a modern tech stack.
Strategic consulting of CTO and Head of Product for tech stack management regarding the product vision.
Optimised performance and profoundly simplified the overall system architecture, unlocking cost savings and improvements to the development process.
Updated the Linux OS, Ruby, Rails, nodeJS, MongoDB as well as other libraries; adapting code and tooling for development, build and deployment; implemented server provisioning with Ansible, introducting IaC.
Ported a Sinatra app to Ruby on Rails, with wide-ranging refactoring, using Hotwire, Stimulus and Tailwind.
Introduced a container based DevOps workflow using Docker Compose and Hashicorp Nomad.
Part-time engagement.
Ruby on Rails 3→ 7
Sinatra
R
MongoDB 2→ 6
nodeJS 0.8→ 16
Javascript
Typescript
BackboneJS
CoffeeScript
Redis
Hotwire
Turbo
StimulusJS
TailwindCSS
Git
PRTG→ Prometheus
Loki
Grafana
Ansible
Capistrano→ Nomad
VMware
LXC→ Docker
Git
Github
Centos Linux→ Ubuntu & Alpine Linux
OpenProject
Jun 2021 - May 2022
1 year
Munich, Germany
Lead Developer
Die Produktmacher
Development of a new web app for medical personnel to collect treatment and drug con-sumption data of haemophilia patients, and report those to the German Haemophilia Registry (DHR), for florio GmbH / SOBI AB.
Interfaces to an internal JSON API and to the DHR SOAP API provided by Adjumed.
Supported the client with crucial product concept considerations and UX design.
Designed the system’s architecture and data model.
Developed critical components, e.g. a SOAP-API client with 2FA via IMAP.
Data management and protection according to medical technology standards.
Ruby 3
Rails 6/7
PostgreSQL
Redis
Sidekiq
JSON-API
SOAP
XML
IMAP
HotwireJS
Turbo
StimulusJS
Less CSS
RSpec
Service Objects
Design Patterns
Feature Flags
Full remote
Jira
Confluence
Slack
MS Teams
Google Meet
Github
Pair programming
Code Review
Figma
Make
Docker
CircleCI
AWS
Internally agile (SCRUM)
Client-side waterfall
Nov 2018 - Dec 2022
4 years 2 months
Burgwedel, Germany
Software Architect and Lead Developer
DistriSmart GmbH / papersmart.de
Controlling of a complex refactoring process of core components for a business model pivot from B2B to B2C.
From 2018 on further development, maintenance and support (part time), advising the new owners of potential directions of product development.
Technical Lead of 4-6 developers; interviewing and onboarding.
Planning and implementation of functional extensions for B2C customers.
Development of a new system architecture using service objects, i.e. Interactors.
Payment process integration via Payone, Paypal, and later Stripe.
Integration and development of various interfaces: BMECat, eClass, WebValid, ClosedFinance, Optiva, TrustPilot, as well as data import from CSV and XML files.
Implementation of JSON APIs for article data, bulk prices, inventory; integrating an in-house ERP system.
Upgrade from Rails 3 to Rails 4, migration from MySQL to PostgreSQL.
Preparation of scaling concepts, load tests.
Ruby on Rails 3-5
MySQL
PostgreSQL
Memcache
Sphinx
ElasticSearch
DelayedJob
Prawn
RSpec
Cucumber
JSON
XML
SASS/CSS
jQuery3
ActiveInteraction
StateMachine
Full remote
Slack
Google Meet
Asana
Gitlab
PivotalTracker
Code Review
Semi-Agile inspired by SCRUM
Ubuntu Linux
Baremetal Server
Ansible
Capistrano
Mar 2015 - Dec 2019
3 years 10 months
Berlin, Germany
Interim CTO, Technical Product Manager, Senior Ruby on Rails Developer
Wimdu GmbH
Interim CTO along with the infrastructure team lead, from November 2017 til February 2018.
Regular board meetings; hiring process and technical interviews for CTO candidates, onboarding of and hand-over to the CTO successor.
Technical Product Manager since June 2017, after introducing this role to the team.
Advisory cooperation with the product owners team.
Technical lead of up to 25 developers, including a near-shore team.
Driving large-scale refactoring processes for performance improvements to the systems architecture and in the development processes, as well as to enable compliance features.
As Senior Ruby on Rails Developer, developed many new features of the then-leading European accommodation market place.
Lead the onboarding process for new developer teams as well as for product managers.
Interviewing, team lead, moderation, coaching.
Guided the transition from a monolithic to a (micro-) service-based architecture.
Introduced organisational improvements, e.g. an internal RFC process inspired by EmberJS & Rust.
Payment integration via Adyen, for incoming and outgoing payments in several currencies.
Integration of GetYourGuide's REST APIs.
Compliance topics: implementing GDPR; extended KYC for payment receivers (hosts).
Ruby on Rails 4/5
service objects
dry-rb
GraphQL
MySQL
ElasticSearch
Redis
Sidekiq
Memcache
Haml
Sass
Compass
BackboneJS
ReactJS
TDD
RSpec
Capybara
Watir
Cucumber
A/B Testing
Feature Flags
Hybrid remote/in office
Slack
Google Meet
Jira
Confluence
Trello
Github
Pair programming
Tech Talks
Hackathons
Capistrano
LHM for MySQL
Docker
Chef
Puppet
Terraform
Heroku
AWS CloudFormation
S3
Rackspace
SCRUM / LESS, moderating all ceremonies
Kanban
Engineering Meetings
May 2014 - Sep 2014
5 months
Burgwedel, Germany
Software Architect and Lead Developer
DistriSmart GmbH / papersmart.de
Hired and lead the development team for the 2014 relaunch of the price comparison shop for office supplies.
Technical Lead of 4-6 developers; interviewing and onboarding.
Planning and implementation of functional extensions for B2C customers.
Development of a new system architecture using service objects, i.e. Interactors.
Payment process integration via Payone, Paypal, and later Stripe.
Integration and development of various interfaces: BMECat, eClass, WebValid, ClosedFinance, Optiva, TrustPilot, as well as data import from CSV and XML files.
Implementation of JSON APIs for article data, bulk prices, inventory; integrating an in-house ERP system.
Upgrade from Rails 3 to Rails 4, migration from MySQL to PostgreSQL.
Preparation of scaling concepts, load tests.
Ruby on Rails 3-5
MySQL
PostgreSQL
Memcache
Sphinx
ElasticSearch
DelayedJob
Prawn
RSpec
Cucumber
JSON
XML
SASS/CSS
jQuery3
ActiveInteraction
StateMachine
Full remote
Slack
Google Meet
Asana
Gitlab
PivotalTracker
Code Review
Semi-Agile inspired by SCRUM
Ubuntu Linux
Baremetal Server
Ansible
Capistrano
Sep 2013 - Dec 2014
4 months
Dresden, Germany
Senior Ruby Developer
Saxiona AG
Development of new features, refactoring, architectural consulting and third level support for AMOS, an in-house backend system for high-profile web shops (e.g. bonprix.ru, quelle.ru, otto.ru) for Otto Group Solution Provider GmbH.
Ruby
JRuby
RubyQt
ActiveRecord
SOAP
Oracle
PL/SQL
Subversion
Windows
Vagrant
Ubuntu Linux
Qt Designer
Oracle SQL Developer
Classic waterfall
Founder
Own Start-up
Industry software development and consulting.
Web & Print Design.
Summary
16+ years Team Lead, Agile Development, Ruby on Rails, Javascript
23+ years Web development, Hosting, SaaS, Marketplaces, ETL, APIs, E-Commerce, Payment, Logistics, Content Management, Healthcare
26+ years Software Engineering, Consulting, Coaching, Databases, Linux Server Administration
Languages
German
Native
English
Advanced
Hindi
Elementary
Spanish
Elementary
Education
Oct 2001 - Jun 2007
Leipzig University
Indology · Science of Religion · Leipzig, Germany
Oct 1995 - Jun 2001
Otto von Guericke University Magdeburg
Informatics · Anglistics & American Cultural Studies · Magdeburg, Germany
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