jkwebs jkwebs

Portfolio of Jakob Hilden

About me

I work as a Full Stack Web Developer at the lovely small web agency Railslove in Cologne, Germany. At Railslove I help clients to ship awesome products on the web and to build successful development teams. I especially enjoy helping early stage startups scaling their business.

Besides client work I also have a couple of side projects that I like to work on. This includes being an active facilitator of the local developer community (Refugees On Rails, Cologne.rb, Railscamp, CoderDojo) and contributing to some small open source projects.

My academic background is in Human-Computer Interaction (HCI) and I'm generally very interested in everything that happens between users, web applications and other users. Besides Frontend Development, this also involves UX & Interaction Design, Analytics, User Research, and Product Management.

I'm also extremely interested in everything that makes a team work well together. I like to establish and improve agile development processes and to create supportive team environemnts (e.g. through techniques such as non-violent communication).



These are the main clients I have been working on as part of my work for Railslove

DaWanda 2017 - 2018

Marketplace for DIY products

Railslove has been a strong pillar of the development department at DaWanda for multiple years. During my time with DaWanda I spearheaded an iterative migration project of their frontend code to react-rails and React. I also co-led the team that was in charge of the technical part of the aquisition by Etsy in 2018.

Blogpost about our time with DaWanda (German)

Primed Mind 2017

Mindset Coaching app build with React Native

I led the team that built and shipped the first version of this app for Android and iOS. We built it using React Native for the app and Phoenix/Elixir on the backend.


ILPT (I Love Personal Training) 2016

Cross-platform mobile fitness app written in Ember.js and Cordova.

This app has been originally developed by our friends at 5apps and I lead the remote development team during 2016, pushing topics like internationalization and build automation.


makerist 2013 - 2015

Platform for DIY resources (video tutorials, patterns, supplies etc.) from Berlin.

I have been leading makerist's web development from day one and together we grew the company to a size of 30+ employees, with respectable revenue and traffic. We helped establishing a healthy inhouse development team of 4 developers, which has been running makerist since 2016.

makerist.de | coverage on deutsche-startups-de [de]

testhub / UI-Check 2012 - 2013

A platform that offers crowd usability and quality assurance tests. We migrated UI-Check (as Testhub was previously known) to Rails, helped the company to scale up, and build an inhouse team. Eventually they got successfully aquired by Applause.

testhub ist jetzt Applause EU [de]

9flats.com 2010 - 2012

Peer-to-peer private accomodation rental website founded by Stephan Uhrenbacher.

We did the initial development and scaled up the company and inhouse development until they stand on their own feed. I developed myself into a leading developer role during this project.


Side projects

Refugees on Rails

In 2015 I co-founded the Cologne chapter of Refugees on Rails, an initiative to teach programming to refugees in Germany.

Facebook | Website


I'm an active coach in the Cologne CoderDojo and enjoy mentoring kids between 7-17 years and their programming projects. In addition I also participate as a coach in JugendHackt


Railscamp Germany

2013 and 2014 I organized the Railscamp Germany in Cologne.



Ruby user group from Cologne. Since 2012 I help organizing the user group and building/maintaining the website (which is a fork of the Ruby user group from Hamburg onruby.de

Website | GitHub


Ruby gem for visualizing i18n strings alongside their keys within the frontend of internationalized Rails/Ruby web applications.


TraxelPipe retired

A simple Sinatra app for debugging "traxels" (tracking pixel, etc.) HTTP requests in a staging/development environment. Built using Pusher and deployed on Heroku.


TabViz retired

Project to design a feature for usefully visualizing open tabs (and their hierarchical relations) within a web browser. We implemented a simple prototype in form of a Firefox Addon and were awarded the "Best in Class" honor in the category "Innovation" of the Mozilla Labs Design Challenge 2009.

ArsTechnica article | Firefox Addon Code

Gallery 2008 - 2009

Leading open source online photo management software. I was active in the project from 2008 until 2009, first as a "Season of Usability" student, and later as a frontend developer and UX mentor.

Project website

Talking-Points retired

Designing a Community Driven Orientation System for the Blind. I co-founded this research project in 2008 and helped designing and building several prototypes. It was a selected project of the GROCS research competition 2008 and funded with $10.000. We presented the paper "Accessible Contextual Information for Urban Navigation" at the Ubicomp Conference 2008 in Seoul, South Korea.

Ubicomp 2008

Professional Experience

Frontend Web Developer since 2010

Railslove, Cologne -- web development agency specialized on Ruby on Rails and early stage startups.

I'm doing frontend development and product design support for various clients, especially 9flats.com

railslove.com | My profile page

Usability Manger 2009 - 2010

Traveltainment AG, Aachen -- market leader in the German online travel distribution industry.

I was responsible for analyzing and improving the usability of the Traveltainment products and lead the product management of a next generation travel e-commerce site.


Freelance Web Developer 2001 - 2009

Since 12th grade in high school I have been doing freelance work as a web developer & designer, working for various small clients and different internet agecies.


Master of Science in Information
2007 - 2009

University of Michigan, Ann Arbor

Specializations: Human-Computer Interaction, Social Computing, User Centered Design

UM School of Information

B.Sc. in Applied Communication and Media Sciences 2004 - 2007

University of Duisburg-Essen, Campus Duisburg

Specializations: Computer Science, Psychology, Art & Design, Social Sciences



Email: info@jkwebs.de | Twitter: @jkwebs