Roman Heinrich

Autoland GmbH - Consulting projectAugust 2021 - July 2022

Tech Elixir (Phoenix) / Liveview / React.js / Tailwind.css /

SQLite3 / Codegeneration / Crawling

• Implementation of autoverkaufen.de - an online car buying platform
• beginner-friendly project setup, that takes the best from Phoenix and React.js without becoming a full-blown SPA
• Integration with a big German cardealership platform (mobile.de) to enable automatic price estimation in the offer
• Integration with the biggest car configuration provider in Europe (DAT.de)
• uses code generation to keep the API-clients up-to-date, because of the amount of smaller details
• Configuration and 3rd-party data is stored in a SQLITE DB, to simplify local development and sharing of data
• Backoffice in Liveview, to allow granular code encapsulation and micro-frontends-like composability
• High-performance crawler to quickly cache 3rd-party data locally
• Consultation was done remotely

Qwzrd - Consulting projectApril 2021 - July 2021

Tech Elixir / Typescript / Mathlive / Mobx / Mobx Keystone / React.js / Chakra UI

• A prototype to create online exercises for math tutors
• Consultation was done remotely

Sabbatical yearMarch 2020 - March 2021

• spent time with my family
• Lots of non-technical reading
• Research into high-performance implementation techniques
• Game design / resilient architectures / deterministic programming

Taxfix GmbHSr. Developer - Nov 2019 - Feb 2020

Tech Elixir / K8S / CircleCI / Grafana / InfluxDB / CLIPS (expert system)

• Optimized CI pipeline from 45 minutes to 8 minutes (commit -> deployable container)
• Heavily parallelized all possible tests suites + heavy CI caching
• Facilitated asynchronous and written standups
• Proposed an alternative, much faster opensource expert system - CLIPS
• Wrote a transpiler for TaxML (tax rules language) to CLIPS (60% functionality covered in 4 weeks spare time development)
• Encouraged the team to take full ownership of the TaxEngine application

Talon.one Teamlead / Sr. Developer / Hiring manager - Aug 2017 - Nov 2019

Tech Golang / Postgres / Kubernetes / GCP / SRE / DevOps

Highlights - People (Hiring / Onboarding / Mentoring)

• Hired and built up a small (4 people) but very capable team for our backend
• Provided all needed resources to new members to become productive as quickly as possible
• Empowered our team to take full ownership of our application
• Facilitated knowledge sharing and encouragement for controlled experiments
• Ran retrospective and iteration meetings, continuously adapting and improving processes
• Encouraged/supported responsibility for production within the team
• Continuously provided moral support and a safe environment for experimentation within our team

Highlights - Tech (idea giver / supervisor / reviewer / collaborator)

• Realtime streaming data export within constant memory consumption from Postgres
• Introduced very fast data importer by using parallel COPY statements from Go into Postgres
• Introduced partitioned tables for logs stored in Postgres to enabled quick old data deletion and faster queries
• Infinitely flexible API query parser inspired by the MongoDB query language
• Automation for SSL Certificate renewals
• Automatic multi-cluster Kubernetes setup (GCP)
• Multitenant Kubernetes Deployment automation via internal tools (Elixir)
• Kubernetes Operators for Secrets / auto-updating deployments / Database configuration via CRD
• Internal multitenant central logging system based on TimescaleDB (for central visibility)
• Introduced Redash.io for customer data analysis
• Split up our integration API tests into parallel chunks to stay consistently below 2 minutes
• Encouraged to invest heavily in a very stable CI solution
• Continuously helped improving visibility/stability of the platform

Solarisbank Sr. Developer / Teamlead - Mar 2016 - Jul 2017

Tech Elixir / Clojure / Ruby / Golang / Docker

• Teamlead for the "Credit API" project
• Loan application API via mobile UI (Elixir / Phoenix)
• administration backend / contract generation / scoring algorithm / core banking system integration
• tight focus on TDD and quick turn-around times
• Elixir mentoring among fellow developers
• integration with multiple third-party financial services
• integration with Schufa SOAP interface (Java / Clojure / Elixir)
• introduction of Eventsourcing / CQRS in Solarisbank
• introduction of fundamental DDD concepts in Solarisbank
• https://github.com/ddd-ruby

TD Reply GmbHSr. Developer / Teamlead - Feb 2014 - Feb 2016

Tech Ruby / JS / Coffeescript / React.js / D3.js / Karma

• Configurable dashboard frontends for 6 corporate clients on tight deadlines
• Coaching jr. developers (intense pairing sessions, code reviews)
• Generic streaming Excel parser without loading complete file in memory
• Maintainable, unit-testable JS / Ruby code
• working with React.js since April 2014

Mediapeers GmbHSr. Developer - Aug 2013 - Jan 2014

Tech Chef / Rails / Angular.js / AWS(S3/EC2) / MongoDB

• Introduced Angular.js as UI framework
• AWS automation with Chef

Dawanda GmbHOkt 2008 - Apr 2013

Role Rails developer / SRE / DevOps engineer / MySQL DBA

Tech Puppet / Ruby / MySQL-Percona / AWS(S3/EC2)

 Redis / Varnish / Solr / Monitoring / Ubuntu / OpenVZ / OpenStack / etc

• Fullstack optimization
• DB queries optimizations
• LOTs of caching solutions
• Deployment automation
• Collocation server management
• Hardware maintenance / replacement / assembly
• Efficient virtualization with OpenVZ (ancestor of Docker)

Deutsche Bank/DVAG ventureConsultant - Jul 2007 - Okt 2007

Tech Java, Groovy, JUnit, Java Reflection

• Integration financial loan calculation library

University Paderborn cooperationAug 2007 - Sep 2007

Ceyoniq Technology GmbH

Tech Flex 2, ActionScript3, AIR, 3D, Usability

• Innovative DMS-Client Prototype for DMS-Messe in Cologne

Deutsche BankApr 2006 - Jan 2007

Tech VBA 6.0, Excel 2000, PDF-Generation

• Housing Loan Consulting Tool
• Extensive VBA code generation
• Complex business rules, that could be quickly adjusted to market needs
• Consultation was done remotely

Deutsche BankAug 2005 - Sep 2005

Tech VBA 6.0, Excel 2000, PDF-Generation

• Student Loan Consulting Tool
• Consultation was done remotely

Deutsche BankApr 2005 - Mai 2005

Tech VBA 5, Excel 97, Acrobat, PDF

• TopCredit Consulting Tool
• Consultation was done remotely