Our projects

We have a lot of great customers and those customers bring us wonderful projects. For us, it goes from working for the Efteling to implementation work for payment platform Mollie. We have large and small assignments, continuous SLA contracts or small pre-paid cards for sporadic help.

Every day we are busy taking care of this set of projects. But we also make time for our own projects such as www.fourauctions.nl or our own support system to further improve the customer experience.


What makes us different as a company is our emphasis on quality. A computer can test better, more consistently and faster than we can. All our projects, both front and back end, are now equipped with automatic tests. But the way of programming and offering tickets are also laid down in our working methods.

  1. ISO 9001 certified

    Four Digits is ISO 9001: 2015 certified (since 2009). Our business processes are evaluated three times a year. In this way we keep learning and we keep improving ourselves.

    For our customers, the certifications provide certainty in how we deal with projects, policy and information.

  2. ISO 27001 and NEN 7510 certified

    Four Digits is ISO / IEC 27001: 2013 and NEN 7510-1: 2017 certified (since 2019). The information security policy at Four Digits aims to safeguard the continuity of the business process and minimizing the damage caused by prevention of information security incidents and minimizing any consequences of these incidents.

  3. Our way of working

    Every change in code is checked by at least one other developer. In this way we guarantee that not only the code is good, but also that the approach solves the customer's problem. Our Python code adheres to industry standards and we adhere to Django coding conventions. For Javascript and React we use the AirBnB style guide. We write meaningful commit messages and code comments.

  4. Automatic tests

    The larger an application, the less feasible it becomes to manually check that everything still works exactly after an adjustment. Automatic tests help to discover this, so that an adjustment does not have unexpected side effects. We have years of experience in writing automatic tests, and the measuring of coverage.


We develop custom software and are specialized in creating and offering web applications and everything that comes with it.

Our mission is to develop and offer web-related products and services. We strive to develop user-friendly and high-quality software based on innovative technologies to provide up-to-date and industry-leading solutions. In our view, software is a reflection of reality.

We also work for

logo of STOWAlogo of NHIlogo of Atlancelogo of Stoffenmanagerlogo of Naturalislogo of Shionogilogo of Eightlogo of Cibitlogo of Zumtobellogo of Artronlogo of Epic Auctionslogo of UMC Utrechtlogo of Saxionlogo of HANlogo of Liemerijelogo of Gemeente Groningenlogo of Gemeente Arnhemlogo of Gemeente Deventerlogo of Ampedlogo of Aviralogo of NSDSKlogo of Beter Wonen Vechtdallogo of NCOI groeplogo of Barriquelogo of Sonsbeeklogo of NPOlogo of Atlancelogo of Luzaclogo of Melexislogo of WVNLlogo of Intergammalogo of One Acre Fundlogo of Hoogheemraadschap of Rijnlandlogo of Nobbe Mieraslogo of Marqtlogo of Vivare
We love code