Senior Product Designer

What did I do at Marktplaats?

Recalibrating the balance between user needs and business requirements. Optimising search capability and user journeys across professional sellers and independent advertisements.

At Marktplaats I mainly focused on the Finding Journey.

The multidisciplinary team included native and web developers, data specialists, QA, Delivery Lead, and a Product Manager. I helped to develop concepts and strategies for search, filters, result pages, overview pages, detail pages, display advertisements and wider cross-company concepts.

I also worked on a multi-tenant platform for eBay companies and Gumtree UK.

  • User research (A/B Testing, Usability testing, etc.)
  • Customer Journeys
  • Jobs-to-be-done’s
  • Product Design
  • Web, Android, and iOS
  • Prototyping
  • Strategy
  • North Star Concept
  • Design Systems
  • Sketch
  • Abstract
  • Invision
  • Principle
  • Jira

“Pro-actively helping our users to find their buyable items”

Designing better filters


Filters were the first area to improve at Marktplaats. What were the problems? How could we measure success? How did other apps use filters and how could we improve the user experience?

Our aim was to improve the consumer experience of using filters: for accurate, understandable results that could directly contribute to the quarterly objectives. We looked at the issues end-users had with current filters then worked to improve information flow and usability.

To have the filters visible at all times was a huge improvement, despite the fact that most users didn’t know the new filters could horizontal scroll. They had the most important filters in sight.

Searching for answers

Search bar

Searchability is key to finding the right item. I did lots of research into how buyers search and how they find their buyable items. More than 80% of our buyers use the search bar as their main navigation. So I used that knowledge to enhance the search bar.

You can do much more than just wait for the buyer to give input. So I designed screens for before and after the user types something. If you give suggestions, show last or saved searches or recent things they looked at, for instance, you’ll improve their search massively.

Adding value is adding money 💸

Mobile Monetization

Whether you are a major brand or a professional seller, Markplaats is helping sellers to be relevant and successful for buyers.

I designed native ads, brand listings pages, sponsored Guided search, and many more brand engagement concepts.

Creating concepts, validate them, and A/B test them to see how we could help brands reach the right buyers with their Touch, Tell, and Sell strategy.

How to make advertising relevant and loved

Buyers ♡ Admarkt

This is still the most difficult challenge Marktplaats faces: how to find the right balance of ads and listings.

Initially, we tested adding new concepts to reposition professional sellers. But our tests showed that buyer sentiment against professional sellers remained too high.

So I created a white-labeled prototype to validate our hypothesis that new and secondhand ads could exist on one platform. I did a lot of guerilla testing at Amstel Station with passengers and iterated my designs every week. The initial results were quite impressive. The negative sentiment was kind of gone and those tested really gave me the feeling that new and secondhand could live together. But the overall findings were a lot more complex. This topic needs much more research in my opinion.

Creating a proper working library system for all designers

Atomic design

Since Sketch implemented symbols, I’m creating symbols in symbols in symbols in symbols in symbols. (Stay with me!)

Genuinely, I created super complex symbols that even got connected with the real-life production feed of ads via JSON in Sketch.

I also created icons like this beautiful heart-shaped handshake (this is so not corona proof)

Design System Language

Multi-tenant Branding

Working on a design system is not all about design. Actually, it’s not about design. It’s about a system to collaborate and communicate with the whole company.

A system with principles, translation, complex three-tier color schemes, from high-level agreements to very specific components.

Working with development and business to create an ecosystem that would work brand agnostic and platform agnostic, but translates brand, platform, and component-specific output.

Case Studies


Buyers ♡ Admarkt

Password protected 🔒

Check out this case study

Jeroen Mulder

Head of UX, eBay Classifieds (Benelux)

One of Michel’s greatest strengths is his ability to quickly explore a wide range of design directions, prototype them, iterate and decide. It allows him to lead through storytelling as well as concrete prototypes that visualize the opportunity and aligns people from different functions and backgrounds.

Overall one of our key challenges is raising the design maturity in our organization and Michel has contributed to that greatly.

It is not an easy environment and despite those challenges, Michel has had a laser focus on the goal of establishing design as a leading role, yet in a collaborative manner, while also initiating constructive conversations in times of conflict.