Leif Gensert, Software Developer in San Diego, CA, United States
Leif Gensert

Software Developer in San Diego, CA, United States

Member since February 14, 2018
For the past eleven years, Leif has worked as a full-time developer focusing on back-end development utilizing Ruby or Elixir. He's worked for giant consulting firms and newly founded startups. Through side projects and open source contributions, he makes sure he stays up to date on the latest tech. A healthy sense of pragmatism keeps him grounded to choose the technology that makes sense as opposed to going with whatever is hip right now.
Leif is now available for hire




San Diego, CA, United States



Preferred Environment

Tmux, Git, Visual Studio Code (VS Code)

The most amazing...

...side project I've released is HN Vanity: an event-sourced application for getting basic hacker news statistics.


  • Developer

    2018 - PRESENT
    Tata Steel DV
    • Scoped, planned and implemented new features to an internal application.
    • Delivered a massive integration change with Zoho Books.
    • Integrated Hubspot CRM.
    Technologies: PostgreSQL, Heroku, Ruby
  • Developer

    2018 - 2018
    Blend Media
    • Supported the development of new features.
    • Came up with a new concept for the publishing pipeline of 360° videos.
    • Successfully integrated the product with Salesforce Pardot.
    Technologies: PostgreSQL, Elixir
  • Freelance Developer

    2017 - 2017
    QT Mobilitätsservice GmbH (Qixxit)
    • Introduced a new CI pipeline to improve deployment processes and regression tests.
    • Built an automated acceptance test suite to give product department a better overview of the state of development.
    • Implemented a proof of concept for a routing engine based on pgRouting.
    Technologies: pgRouting, Docker, Neo4j, PostgreSQL, Elixir
  • Freelance Developer

    2016 - 2017
    solarisBank AG
    • Implemented a database anonymization program for efficiently creating test data.
    • Improved the existing continuous integration process.
    • Created a notifications feature in the core applications that sent out messages via WebHooks.
    • Worked on a prototype for a core banking system built in a CQRS way.
    Technologies: Docker, PostgreSQL, Apache Kafka, Elixir, Ruby
  • Senior Developer

    2013 - 2016
    Propertybase GmbH
    • Designed and implemented a periodical import tool to fetch listing data in different formats (JRuby).
    • Implemented and maintained the lead generation tool while working closely together with customer success and sales teams to further adapt the tool to new inbound channels.
    • Handled and managed the technical onboarding of new clients (including data migration to Salesforce).
    Technologies: Salesforce, Redis, MongoDB, PostgreSQL, JRuby, Ruby on Rails (RoR), Ruby
  • Senior Developer

    2011 - 2013
    stylefruits GmbH
    • Maintained and improved the main application (Ruby on Rails).
    • Developed a URL-shorting service (Sinatra on JRuby).
    • Designed and implemented a back-end to manage language translation tokens (Sinatra).
    • Managed and handled the weekly testing process—writing automated scripts and overseeing the manual testing sessions.
    Technologies: MySQL, Redis, Ruby on Rails (RoR), Ruby
  • Senior Software Engineer

    2008 - 2011
    • Improved and maintained a Java-based web application for Deutsche Telekom AG (OMS-IP).
    • Led workshop lessons regarding knowledge transfers for an offshore team in Kolkata, India.
    • Maintained an invoicing system for a satellite TV provider in Munich.
    • Improved an internal continuous integration workflow by dynamically dispatching test cases to concurrent processes.
    Technologies: Oracle, Java
  • Developer

    2005 - 2008
    Process Innovation Ag
    • Developed for the web with Java and JSP.
    • Worked on IMB Lotus Notes and IBM DB2 development.
    Technologies: Lotus Notes, JEE, Java



  • Languages

    Ruby, Elixir, JavaScript, Elm, Java, JRuby
  • Frameworks

    Ruby on Rails (RoR), Phoenix
  • Paradigms

    REST, CQRS, Event Sourcing
  • Libraries/APIs

    pgRouting, Salesforce API, Salesforce Bulk API, Salesforce REST API, React
  • Tools

    Git, Tmux, Lotus Notes
  • Platforms

    Salesforce, Visual Studio Code (VS Code), Oracle, Apache Kafka, Docker, Heroku, JEE
  • Storage

    Redis, PostgreSQL, MySQL, MongoDB, Neo4j
  • Other



  • Bachelor's Degree in Computer Science and Business Administration
    2005 - 2008
    DHBW Karlsruhe - Karlsruhe, Germany
  • Bachelor's Degree in Computer Science
    2005 - 2008
    The Open University - London, England

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