Martijn ter Hellen

Freelance application/web developer and technical consultant


I'm a passionate developer with a wide range of skills. Love to craft an application from scratch with minimal cruft and pay attention to all kind of details without compromising deadlines.

Able to code all sorts of front and backend solutions. Throw some designers design at me and I will tell you if it can be done, how I think it should be done and build it accordingly.

When a project comes to life I want to be involved in its life cycle. As a technical consultant I will give my sincere advice about all things technical. I love to debate with designers about form, function and user experience.

Martijn ter Hellen

I'm currently living in Ouderkerk aan de Amstel, the Netherlands, with my girlfriend and two kids. I love to produce music.


  • Founder & owner of Status Code
  • 20+ years of experience in frontend, backend and mobile/tv app development
  • structured, ordered, quality-freak and blessed with a carpenters eye
  • strong focus on getting things done
  • able to quickly translate client needs into working prototypes
  • capable to lead
  • technical consultant
  • concept thinker
  • true autodidact
  • project manager
  • design advisor



Status Code

Januari 2019 - present

As of 2019 I've founded Status Code and it has been an adventurous journey so far. I've had the pleasure to work on diverse range of projects with lovely people at all kind of companies.

With Status Code I can be able to do what I love most and be self-sustained at the same time! So, if you want to hire me, Status Code is where you need to be.

Lead Developer


December 2016 - June 2018

At Peakfijn we're building web, single page and native applications for startups. We're using a broad range of languages, techniques and skills. Frontend libraries like React and Vue.js are preferred for web based applications. React Native is used for mobile applications for iOS and Android as well as pure Swift in some cases. On the server side we mostly use Laravel to build our API's and generated pages.

Clients included Sprynter, Shleep, Bksy, Beatt, Unilever, Van Lanschot, Split a Gift and DermExpert among others.

Lead Developer / Technical consultant

The KEY Agency

January 2009 - November 2016

As lead developer at KEY I was in charge of all web development within the company and responsible for continuity of our framework and all released projects by our development team. I managed projects when they were in their development cycle, assured quality, deadlines and as a technical consultant I was actively involved in meetings with clients.

Senior Web Developer

The KEY Agency

January 2006 - December 2008

Not happy with my xml/xslt based framework, I started working on a complete rewrite of our main development framework. We chose CodeIgniter to be at it's core, which, back then, was among the best out of the box. It had excellent documentation and was easy to grasp.

Alongside I crafted my second CMS on top of this framework. This CMS is still being used now and received numerous updates and bugfixes over the years.

As I got more responsibilities within the company I found myself in a leading position.

Web Developer

The KEY Agency

October 1999 - December 2005

This was the start of my professional career as web developer. These were the days of layouts with html-tables, spacer.gif, Netscape, the dreaded Internet Explorer 4 & 5 for Windows and development under Mac OS 8 & 9. It's where I met with HTML, PHP, MySQL and Javascript.

I got to make a lot of websites for companies that at that time even hadn't had a website. It was fun with a lot of exploration and some (hard) lessons were learned by me and our development team.

Things started to get more streamlined and more complex. PHP began to play a huge position-role in our development cycle. I build a custom CMS which made up for a significant increase in development time.

Junior project planner / Architectural draftsman

Hasselerharm B.V.

November 1998 - July 1999

Freshly graduated as an Civil Engineer I landed at my first real job in this line of field. And what a misfit it was... I was put on a large warehouse under construction and needed to draw countless drawings of prefabricated concrete elements. It was boring as hell.

At the time I was doing some web development for family and acquaintances. Loving this hobby and urged by my need to get away from my current employer I applied for a couple of web developent positions.

Architectural draftsman / Designer (internship)

Architekten Kollektief Heijdenrijk

Februari 1998 - August 1998

At Heijdenrijk I sat alongside architect Leo Heijdenrijk. With other colleagues we were translating his plans, sketches and drawings into technical drawings.

Supervisor (internship)

Amarcon B.V.

August 1997 - Februari 1998

Adjecent to Amersfoort Central Station rises a tall officebuilding called "de Argonaut". At the time this building was constructed I've been roaming the construction yard as an architect supervisor. Main responsibility was to make sure that the contracter constructed every bit of this immense building according to technical plans.


  • build tvOS, AndroidTV, Tizen and webOS applications with React Native
  • build a scalable payments-related application within Azure
  • build iOS and Android applications with React Native
  • build spa's with React
  • build apps with Laravel and Vue.js
  • build api's with Laravel
  • build native applications for iOS with Swift
  • setup continuous integration (Github Actions, Fastlane, TestFlight)
  • craft lots of websites, responsive websites, e-mailings, applications and application parts
  • create a solid foundation on which almost all of these applications were build
  • build two major versions of a cms with countless updates and improvements over the years
  • lead a small team of developers
  • build custom applications for specific needs i.e:
    • dataroom for real estate property on sale
    • reporting tool for charter planes
    • jobboard system for candidates and employers
    • financial registration system
    • custom data on top of google maps
  • build sites with Wordpress and Concrete5
  • build and publish some native apps in Apples App Store
  • automated Adobe Indesign


Over the years I have become fluent in many aspects of digital development.


  • HTML
  • CSS
  • TypeScript / Javascript
    • React
    • Vue
  • PHP
  • SQL

tvOS / AndroidTV

  • React Native

Tizen / webOS

  • React Native for Web

iOS / Android / OS X

  • React Native
  • Swift
  • Objective C


  • Git / Subversion
  • Xcode
  • Visual Studio Code
  • Docker
  • JSON
  • Markdown
  • XML / XSLT
  • Unix command line
  • Apache / Nginx configuration
  • Filemaker Pro

Extensive knowledge of

  • Object Oriented Programming
  • React and React Native
  • TypeScript
  • Node.js
  • PHP
  • Laravel
  • Continuous integration
  • Web standards
  • Semantics
  • Search engine optimization
  • Content optimization
  • A/B testing
  • Email marketing
  • Security audits
  • Server management on Azure, AWS and GCP
  • Adobe software

Current tools

  • React and React Native
  • Next.js
  • TypeScript
  • VS Code
  • macOS


  • Dutch (native)
  • English


  • passion
  • love
  • care
  • time
  • music
  • coffee


Media Information Technology

Hogeschool Enschede

1999 - 2001

Architecture preparatory year

ArtEZ hogeschool voor de kunsten, Arnhem

1997 - 1998

Civil Engineering

Hogeschool Enschede

1994 - 1998


Twickel College, Hengelo

1988 - 1994