Rens Poesse, Progressive Web Applications (PWA) Developer in Colombia
Rens Poesse

Progressive Web Applications (PWA) Developer in Colombia

Member since June 25, 2018
Rens is a full-stack developer with over a decade of experience leading teams, designing complex systems, and communicating effectively. He also has a background in psychological research and statistics. Having worked for corporate clients, in academics, and for startups, Rens has a deep understanding of various stakeholders while maintaining a young, creative mindset. He was named one of the most promising tech talents according to TNW.
Rens is now available for hire


  • Rens Poesse
    R, Webpack, Tailwind CSS, Sass, CSS3, Server-side Rendering, React, Nuxt.js...
  • Kinder Donations
    Webpack, Bootstrap, Sass, CSS3, React, Vue, JavaScript...
  • Mobypicture
    Android, Bootstrap, HTML, CSS3, Sass, Backbone.js, React, JavaScript, Java, PHP






Preferred Environment

JetBrains, Linux, MacOS, Git

The most amazing...

...thing I've built is a live industrial tracking-and-tracing system that integrates automatic vehicle identification, weighing software and PLC communication.


  • Freelance Developer

    2015 - PRESENT
    Rens Poesse
    • Developed various applications; using Node.js, Laravel, Vue.js/React, SSR, Tailwind CSS, and Heroku or Amazon Web Services.
    • Produced metrics on student matching procedures by analyzing big data in R—generating an effectiveness report.
    • Rapidly prototyped ideas for new apps, including dashboards, chatbots, and voice interfaces.
    • Worked on brand activations for large clients, including IKEA, Rituals, and HEMA.
    • Helped to hire candidates for clients by developing exercises for technical interviews and assessing candidates on multiple relevant skills.
    Technologies: R, Webpack, Tailwind CSS, Sass, CSS3, Server-side Rendering, React, Nuxt.js, Vue, JavaScript, DevOps, Amazon Web Services (AWS), Vagrant, Heroku, Docker, Redis, MongoDB, SQL, C#, PHP, Node.js
  • CTO

    2016 - 2017
    Kinder Donations
    • Managed a scalable Docker stack on Amazon Web Services with PHP, MySQL, MongoDB, and Redis.
    • Built APIs with OAuth implementations and also integrating Algolia search and Stripe payment processing.
    • Created reactive web components with Vue.js and React which increased reusability.
    Technologies: Webpack, Bootstrap, Sass, CSS3, React, Vue, JavaScript, Amazon Web Services (AWS), Docker Swarm, Docker, Redis, MongoDB, SQL, PHP, Node.js
  • Front-end Lead

    2015 - 2017
    • Led the front-end development of a content management system using Backbone.js and developed a corresponding Android app.
    • Reduced image-loading time by up to 50% by implementing server-side image processing which led to a smoother user experience.
    • Developed various front-end widgets, including a 3D map view that uses Mapbox GL to provide a flight journey through photos taken throughout the world.
    Technologies: Android, Bootstrap, HTML, CSS3, Sass, Backbone.js, React, JavaScript, Java, PHP
  • Software Engineer

    2015 - 2015
    • Detected methods of transport by utilizing geolocation data retrieved from native Android and iOS apps.
    • Visualized real-time data on a per-user dashboard which enabled data-driven business decisions.
    • Completely redesigned and rebuilt a website that provides traffic information and route planning, much like Google Maps.
    Technologies: SQL, .NET, CSS, HTML, JavaScript, iOS, Android, GIS
  • Research Assistant

    2014 - 2015
    University of Amsterdam
    • Simulated a parameter estimation for linear ballistic accumulator (LBA) models.
    • Wrote an article that was published in the British Journal of Mathematical and Statistical Psychology.
    • Developed an LTI integration that provides a way by which Qualtrics surveys can be included in a Coursera course for the purpose of A/B testing.
    Technologies: PHP, SPSS, R
  • Software Engineer

    2009 - 2013
    Brainpact Industrial Automation
    • Developed logistic solutions using .NET and automatic vehicle identification technology which resulted in better-facilitated stock auditing.
    • Automated industrial traffic lights by optimizing weighing software and PLC communication layers.
    • Built an ASP.NET maintenance management system with a C# back-end that allows planning recurrent jobs, order placement, and facility management.
    Technologies: PLC, Java, Microsoft SQL Server, C#, .NET


  • Duolingo

    As a front-end contractor, I worked on next-generation education technology that helps millions of people learn on mobile and desktop web.

    • Collaborated on software projects with product design and backend aspects.
    • Developed, released, and maintained web applications.
    • Manage individual project priorities, deadlines, and deliverables.

  • Hello Chef

    I received this review for the work I did for Hello Chef.

    "Rens was the key figure in a team of developers that built our system from scratch. While he mainly handled front-end, it's obvious that he has vast experience in all key areas of software development. Rens kept the entire team organized and focused and ultimately we built a very reliable system. If you're looking for a senior professional to lead on the development of your next complex software project, speak to Rens."

    - Ahmed Al Akber, CEO, Hello Chef

  • Kubernetes and Docker Swarm with CI/CD

    I have set up Kubernetes and Docker Swarm clusters for multiple clients, converting applications to be run in containers, setting up monitoring and centralized logging, configuring replicas, load balancing and automated zero downtime deployments with a CI/CD pipeline.

  • Hack Partners

    I developed dashboards and data visualizations for rolling stock companies, enabling analysis of speed, fuel consumption, etc. of train carriages.

    Technologies: React, Plotly, Grafana

  • Pac-Man, Flappy Bird, and Doodle Jump

    For a campaign of a large brand in the soccer branch, I developed mobile-first adaptations of Pac-Man, Flappy Bird, and Doodle Jump. These were directly advertised on Instagram and were hosted to support large amounts of traffic.

    Technologies: Canvas, Vue.js, Hammer.js, Howler.js, EaselJS, Amazon Web Services

  • Forget the Fish

    I completely rewrote the GrowApp using React. I increased browser support, added localization, and implemented the camera integration.

    With the Grow app, people can make time-lapse animations of the environment through seasons and years, by regularly taking pictures with your smartphone from the same location. These pictures are used to help scientists who investigate the effect of climate change on nature.

    Technologies: React, WebRTC, Onion Skinning

  • Real-time Waiting List and Dashboard

    As part of their new product launch, I developed a real-time online waiting list app for U GO where people could sign up to purchase the product and get notified immediately when it was their turn. Using a custom admin dashboard, the marketing team could also manually move people onto the list.

    Technologies: Vue.js, SSR, Nuxt.js, Tailwind CSS, WebSockets, Heroku


  • Languages

    CSS, SQL, HTML, Sass, JavaScript, PHP, Less, TypeScript, R, C#, CSS3, Java, GraphQL
  • Frameworks

    Vue SSR, Tailwind CSS, Nuxt.js, Bootstrap, Redux, Laravel, Express.js, Koa, .NET, PixiJS, React Native
  • Libraries/APIs

    Node.js, jQuery, Vue, React, Vuex, Chart.js, React Redux, Socket.IO, Reselect, Immutable.js, Backbone.js, Google Cloud API, Redux-Saga
  • Tools

    PostCSS, Docker Swarm, Docker Compose, Webpack, CircleCI, SPSS, Git, Mongoose, Plotly, Grafana, JetBrains, GIS, Vagrant
  • Paradigms

    Reactive Programming, Object-oriented Programming (OOP), Concurrent Programming, Functional Programming, DevOps
  • Platforms

    Windows, MacOS, Docker, Android, Linux, Amazon Web Services (AWS), AWS Lambda, Kubernetes, WordPress, Heroku, iOS, Firebase
  • Storage

    MySQL, Microsoft SQL Server, MongoDB, NoSQL, Redis, Memcached
  • Other

    Responsive Design, Progressive Web Applications (PWA), Data Visualization, Data Analysis, Architecture, Payment Gateways, WebSockets, Learning Tools Interoperability (LTI), PLC, Server-side Rendering, Voice UI Design, Machine Learning, Serverless


  • Master of Science (MSc) Degree in Behavioral Data Science
    2016 - 2019
    University of Amsterdam - Amsterdam, Netherlands
  • Bachelor of Science (BSc) Degree in Psychological Methods
    2013 - 2016
    University of Amsterdam - Amsterdam, Netherlands

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