Know your numbers are right. Then steer by them.

GA4 and GTM audits, dashboards and full funnel analysis. You work directly with me.

Stefan Groen in 't Woud working in his home office

Google Ads says it drove forty sales. Meta says thirty-five. Together you sold fifty.

Every platform is happy to count its own contribution. Added up, that is more sales than you actually had, so every budget you base on it is wrong too.

It is almost never a complicated problem. Usually it is one tag firing twice, one conversion set up wrong, or three departments defining revenue differently. You just need to know which one.

What I help with

Three things, clearly bounded. So you know up front what you get.

For consultants who refer

You can see your client’s numbers are wrong. You just have no appetite for working out why.

If you work as an SEA, social or marketing consultant, you run into this with clients whose measurement you would rather not touch. Send them over; I deliver the report and you keep the relationship.

Your client hears the same price as everyone else, gets the same report, and comes back to you afterwards. I do not take over work that you do.

Data experience for brands such as

From GA4 validation, attribution and web and data analysis to KPI definitions, data quality and Power BI reporting that marketing and management steer on.

Landal commerce analytics

Commerce analytics during the integration of Landal and Roompot

Leading analytics role across the commerce domain: Marketing, Brand, Digital and Revenue. From HQ, together with the countries.

More about this engagementHide the details

Joined during the merger of Landal and Roompot, while the marketing and data organisation was being restructured. What changed since then is set out below.

Was

Data Studio and Tableau, with definitions that didn’t line up

Now

Power BI on Databricks, the same KPIs up to CMO and trade meetings

Measurement

GA4 validated against back-end data, matched on transaction ID

Attribution

Billy Grace, made available via Delta Sharing

UTM

One framework across three brands, two agencies, five countries and every channel

Adoption

Country managers and local teams trained

Worked with

  • GA4
  • Google Tag Manager
  • Power BI
  • Databricks
  • Billy Grace
  • Delta Sharing
More engagementsHide engagements

citizenM customer data platform

CDP implementation from the marketing side

Came in as temporary cover for the marketing data analyst who went on leave, and stayed on after she returned because the CDP implementation needed attention from the marketing side. That is where the questions sit that have to be asked before go-live: which definition do we use, where does a field come from, and is the data quality good enough for management to steer on. Deduplicating accounts was part of it, as was the orchestration plan for marketing and communication, run in Redpoint.

More about this engagementHide the details

Alongside that: GTM implementation and GA4 analyses, and implementation and analysis in AppsFlyer. Connecting that to the CDP later made it possible to add SMS to the journeys.

Before

A purchased CDP that was not yet usable for marketing or reporting

After

Journeys running, data quality monitored, and reporting on real CDP users

Sources

More source systems connected, which made orchestration possible

Journeys

Set up together with the CX, marketing and data teams

Data quality

Deduplication, a front-end email check against new duplicates, and continuous DQ checks

Reporting

On real CDP users instead of online users or sessions

Worked with

  • Redpoint
  • GA4
  • Google Tag Manager
  • AppsFlyer

Nike data governance

Setting up Collibra and de-duplicating metrics

The assignment was to set up Collibra and connect it to the existing reports, dashboards and data. Documenting definitions, origin and lineage made visible how many metrics and reports existed twice.

More about this engagementHide the details

That opened the conversation with business and technical stakeholders: do we keep one definition, or several variants with a clear distinction. Those decisions were documented and surfaced through Power BI.

Before

The same KPI name from different sources, and dashboards that did not say which variant you were seeing

After

Per KPI: what it means, where it comes from and who owns it

Definition

One recorded definition per KPI, with the distinction stated where variants remain

Lineage

From dashboard back to the source where the metric originates

Ownership

A technical and a business owner named per KPI

Usage

From the source, see which metrics are used where and by whom

Worked with

  • Collibra
  • Power BI

B2B Online web and data analysis

Web and data analysis for the agency’s clients

As a Web & Data Analyst consultant, worked for several clients of this agency, which works entirely with freelancers.

Role

The same at every client: tracking and reporting

Agency

Works entirely with freelancers

Collaboration

Always alongside SEA, SEO and CRO specialists

Groen Data

One of its first clients

Worked with

  • GA4
  • Google Tag Manager
  • Looker Studio

What others said about it

Stefan heeft ons geholpen met de creatie van een complex Google Data Studio-dashboard op basis van Google Analytics-data. Daarnaast heeft hij geholpen met het instellen van cross-domain tracking en de nodige tags via Google Tag Manager. Zeer goede samenwerking en een hoog kennisniveau. We huren hem zo weer in.
Pieter de HulluPieterDHWM
Stefan provided training for our e-commerce clients on how to set up Google Analytics for their business and how to use the data to grow their business. I really enjoyed working with him. Stefan has a wealth of knowledge and is very good at sharing it.
Astrid van der MadeSucces met je Webshop
Stefan Groen in 't Woud

The person you speak to does the work

There is no agency and no sales department in between. Technical enough to build the data model myself, and close enough to marketing to know which question sits underneath a reporting request.

On larger engagements I work with a few regular people I know. You hear that up front, and you know who does what.

I use AI daily as a tool for SQL, documentation and reviewing my own code. Definitions, models and conclusions I check myself.

LinkedIn (opens in a new tab)

Free tools

Built because I needed them myself. No account, nothing is sent anywhere.

Talk through a problem

A report that doesn't add up, tracking that needs rebuilding, or a question your data won't answer. You get a reply from me, not from a sales process.

info@groendata.nl

Your message comes straight to me. No newsletter, no CRM follow-up.

Prefer to talk first? Schedule a 30-minute introduction.