CRO specialist

Vacancy: get started as a conversion specialist.

Ensuring higher conversion rates. Your analyses and testing processes turn our clients' websites into conversion bombs.

Yes, we are looking for you!

Persuasion principles, UX and A/B testing. As a CRO specialist, you are completely at home with visitor behaviour on websites. Preferably, you spend all day thinking up creative ideas that you can work out in conversion tests. Just like us! At our agency Onder in Zwolle, we will teach you the tricks of the trade and together we will develop the CRO specialism into a mature service.

Your function

As a CRO specialist, you will be responsible for optimising the conversion rate of our clients' websites and online platforms. You will work on increasing sales and reducing bounce rate through data analysis and A/B testing. Coming up with creative ways to improve conversion, improve UX and increase overall order values is also central to this. CRO is a service still fairly in its infancy, but already running successfully for a number of existing clients at Onder. You will continue to grow in this profession as a CRO specialist at the:

  • Analyse websites with tools such as Google Analytics, Clarity and Hotjar.
  • Coming up with ideas for website improvements and A/B testing.
  • Building A/B tests using Convert .
  • assessing success of the conversion process.

We are Onder

Scoring a high position in Google for our clients, that gives us energy. Pleased to meet you, we are Onder, a specialist SEO agency in the heart of Zwolle. Our ambition is to become one of the best SEO agencies in the Netherlands. Too ambitious? Certainly not. Within our team, we continuously put our heads together to perform above expectations. After all, you never stop learning in this business. Whereas Google is getting smarter and smarter at reading texts, we are constantly taking steps in onder searching, analysing and optimising websites. Obviously within the SEO field, because that is where our strength lies. SEO & CRO is a golden combination, which we also see in front of us. The SEO specialist has many similarities with the CRO specialist.

You will join a team of 10 colleagues, onder divided into two client teams (the A-Team and the B-Eagles). All of them specialists who speak the SEO language like no other. You will probably talk to them in no time. You will get to know our clients and our way of working, but we are also definitely open to change. In the meantime, we sit together every Tuesday afternoon to see what can be improved in our services. Your ideas are certainly welcome here too. If possible, we also try to have lunch together every day while going for a walk. Just stretch your legs!

Your own personal brand ? the best SEO agency in NL

We want to become the best SEO agency in the Netherlands and believe that the development of our colleagues is as important in this as the results for our clients. That is why we are happy to invest in your own personal branding. Specifically, this means that you:

We help you excel and in doing so, you help us excel too.

Who are you?

You know all about or want to learn all about CRO and data analytics. With your eager to learn, you like to jump into the deep end to discover everything within this field. You work accurately, structured and independently. You also have:

  • An HBO working and thinking level.
  • at least 1 year of work experience, e.g. as an online marketer, webmaster or developer.
  • an excessive interest in visitor behaviour

Of course, we are also open to specialists with more experience!

What we offer you

Admittedly, it is sometimes hard work as a CRO specialist at Onder. In return for that, the necessary reward is allowed. For this position (32-40 hours), you can therefore count on:

  • €2,500 to €3,500 salary, depending on experience (junior or medior)
  • A MacBook from the company plus a second monitor at our office.
  • 35 days off when working a 40-hour week. Compulsory days off is not in our dictionary. You can choose whether to work or be off during Easter Monday, Ascension Day or other holidays.
  • luxury pension scheme
  • € 1,100 training budget per year
  • clear development plan and plenty of scope for personal branding
  • the opportunity to work from home regularly
  • a regular DoMiBo (yes, on donderday yes)


This is it, your job! So don't wait any longer and apply today by emailing to celine@onder.nl. Don't forget to attach both your CV and cover letter. We look forward to meeting you!


Our application process is as follows:

  1. An introductory interview: To find out if there is a click between Onder and you and hear more about the contribution you can make to our team
  2. An assessment: no colour test or the like, but a SEO case, in which you can demonstrate your own SEO knowledge and communication skills
  3. Contract proposal
  4. New challenge!

Any questions?

Do you want to know more about SEO? Could your website use a new boost?
Get in touch

This is us!

A team of SEO specialists

Our team consists of enthusiastic SEO specialists who are happy to work with you for the best results.

Meet our team

These customers are supupside down from us!

Renzo van Dongen

Renzo van Dongen

Digital content manager Peugeot

Whether it's about content or technical adjustments, it doesn't matter. Martijn briefs this in a very clear way so that it can be implemented locally or by our head office in France. [...] Since the start of our collaboration, we have achieved great results. Keep it up!

Marien van Stegeren

Eigenaar Kitcentrum

When your online onder venture grows, expectations often grow too, in every area. To a large extent, we were in control of SEO and its interpretation ourselves. We found out that our own "general view" was no longer sufficient, so we engaged Bureau Onder. Surprising and clear. We have built up a fine collaboration, partly because Martijn also regularly visits our office with Eline or Mariska (depending on the case), which is very valuable to us!

Marten Stellingwerf


Martijn and Mariska make the SEO story understandable for the layman and are happy to think along with us. It is nice that there is a personal contact moment every month with an extensive report and the opportunity to talk everything through. After just a few months, Onder has already managed to achieve number 1 positions on Google with some of our webshop pages. We are very satisfied with Onder.

Mark Prummel

SEO Specialist Stella Fietsen

For several years, Onder has been a valued partner of Stella. Martijn is my sparring partner for complex SEO issues and the extra pair of critical eyes that keeps us on our toes. Together, we have achieved nice growth in online visibility, visitor numbers and leads. Onder onder stands out for its short lines of communication and professionalism. They speak our language: don't nag, get down to business. That is what we love!


Don't miss a single SEO insight
  • Insights on SEO
  • For beginners and advanced specialists
  • From experiments to developments at Google and from
    best practices to our own cases
  • A look behind the scenes at Onder

"*" indicates required fields

This field is for validation purposes and should be left unchanged.