From market opportunity to product
I turn customer needs and commercial opportunities into a clear proposition, business model, roadmap and a product that can actually be delivered.
Klaas Joosten · Founder · Interim CEO/CTO · AI Product & Process Leader
From commercial opportunity to
working product.
I help organizations turn commercial opportunities and stalled processes into working products. I align business, technology and AI-driven teams — from proposition and roadmap through delivery and growth, with AI inside the development process itself.
- €20M
- in net sales (2010), sold to Axel Springer
- 4
- platforms built, 3 companies founded
- ~€4M
- in venture funding raised
- 4 mo
- to rebuild ZEEF with AI agents
AI might change everything
As a founder and CTO I have watched from close range how fast AI is moving — and how quickly it is redrawing the road from idea to product.
Claude, ChatGPT and the tools around them deliver an enormous gain in productivity, but only if you rebuild the development process around them. And that rebuild is never finished: what works today is out of date in three months. That is the work I do every day.
What I bring
From manual process to smarter operation
I reduce processes to their essentials and decide where AI accelerates, where specialists remain necessary and where human judgment must lead.
From separate experts to one delivery team
I align developers, marketers, product specialists and AI agents around one goal, so strategy and execution no longer drift apart.
Disciplines
I connect fields that are often organized separately. That turns strategy, product, commercial work and execution into one delivery process.
Product and business development
- Turning customer needs into propositions and roadmaps
- Business models, partnerships and routes to market
- Validating products before scaling the organization around them
- Building distribution into the product from the start
Process and AI transformation
- Mapping where work slows down or loses ownership
- Deciding what AI can take over and what it must not
- Turning experiments into controlled operating workflows
- Keeping human judgment explicit in automated processes
Leadership and delivery
- Directing multidisciplinary product, technology and commercial teams
- Translating between leadership and technical specialists
- Spec-driven delivery with clear decisions and ownership
- Fundraising, budgets, investors and executive accountability
The technical detail, if you want it
AI engineering
- Agent design with tool use, memory and handoffs
- Evals and log tracing that move AI from chatting to production
- Permissions, guardrails and context-window discipline
- Prompt architecture and retrieval design
- Ranking and relevance — ZEEFTCO, a human-in-the-loop engine
Product and platform
- Next.js 16 and React 19, App Router
- Supabase — Postgres, Auth and Row Level Security
- Vercel, serverless-first deployment and preview flows
- Stripe billing and subscription plumbing
- TypeScript end to end, strict mode
- Google Cloud Platform, nine years in production at LinkPizza
From directing teams to AI-driven work
I directed these disciplines for years before applying AI to them. That experience lets me organize the same work faster, with smaller teams and explicit human control. ZEEF is where I learned it from the inside.
Engineering and platform
Then
Directed development teams on a Java/JSF monolith that needed five to seven engineers just to stand still.
Now
Use AI coding agents to understand the full delivery chain and direct AI-driven product teams with decisions grounded in the work.
Marketing, SEO and content
Then
Directed SEO specialists and performance marketers, from affiliate at M4N to influencers at LinkPizza.
Now
Content and SEO pipelines that agents run end to end, with a human holding final edit.
Finance and administration
Then
Budgets, forecasts and annual accounts, plus the accountability that comes with investors and shareholder meetings.
Now
Reporting and administrative flows that AI prepares, so the judgment call is the only part left to make.
Projects
Five chapters, twenty-five years: from affiliate infrastructure and marketplaces to human-curated search. I led ZEEF twice — first with a team, later with AI agents.
ZEEF
2026 — nowFounder, CEO & CTO
Curated search, rebuilt. Every link is chosen by a named curator rather than ranked by an invisible model, and every subject can carry more than one perspective. I rebuilt the product with AI coding agents to learn, from the inside, how AI-driven product teams should be directed.
- Rebuilt single-handedly in under four months on Next.js and Supabase
- ZEEFTCO — a proprietary human-in-the-loop ranking engine
- AI-assisted link discovery on the Anthropic Claude API, in multiple languages
- 5,000+ signups and 3,700+ pages started since the April 2026 soft relaunch
- Next.js 16
- React 19
- Supabase
- Vercel
- Claude
klaasjoosten.com
2026 — nowDesign & build
This site. A bilingual, statically generated portfolio, built the way I now direct client work: designed and written with AI coding agents, with every figure on it traced back to one source file. Building my own shop window was the cheapest way to keep the practice honest — I cannot ask a team to work this way without doing it myself.
- Designed and built solo with AI coding agents, from empty repository to production
- Bilingual by construction: an English field without its Dutch twin fails the build
- Every claim traces to one source file, with tests that fail when a figure drifts
- Static on Vercel: no database, no runtime requests, a strict content security policy
- Next.js 16
- React 19
- Vercel
- Claude Code
LinkPizza
2016 — 2025Founder & CEO
A content, influencer and affiliate marketplace where brands bought collaborations from creators and the platform handled matching, tracking and payments. I led strategy and a 15-person multidisciplinary team, raised €2M and grew the business towards €1M in annual revenue before transferring it to a new owner.
- €2M raised across multiple rounds, a team of 15, towards €1M annual revenue
- Ran entirely on Google Cloud Platform for nine years: compute, data and storage, networking and deploys
- Navigated a marketplace through the COVID collapse in influencer spend
- Handed over to a new owner in 2025
- Produced the ownership-versus-stewardship principle now built into ZEEF
- Marketplace
- Affiliate
- Influencer
- Google Cloud
ZEEF 1.0
2013 — 2016Founder & CEO
The first ZEEF: a curation platform where subject experts built pages of hand-picked links, as a counterweight to algorithmic search. It proved the thesis — thousands of curators showed up — and it proved something else too: a Java/JSF monolith that needed five to seven engineers simply to stand still.
- €1.8M raised, a team of 13
- 11,000 curators, 16,000 expert pages and 3.5 million curated links
- 100,000 pageviews and 35,000 unique visitors a month
- The domain still carries Ahrefs DR 63, Moz DA 60 and roughly 728k backlinks from that era (August 2026)
- The architecture lesson that shaped every rebuild since
- Java/JSF
- Curated search
- SaaS
Zanox (now AWIN)
2011 — 2013CTO Benelux & Integration Lead
After Zanox acquired M4N, I led the technical integration into its international affiliate platform. The role moved me from building a founder-led company to coordinating migrations, data flows and cross-border teams inside an organization of roughly 350 people.
- Migrated affiliates, advertisers and data flows from M4N to Zanox
- Coordinated cross-border integration teams
- Built a scalable international datafeeds system
- International integration
- Affiliate infrastructure
- Datafeeds
M4N
1999 — 2011Co-founder & CTO
The first and largest affiliate marketing platform in the Netherlands: advertisers connected to more than 40,000 websites that recommended their products for a commission per sale. Started in the Hera student house as Mbuyu, after the baobab market tree, and renamed M4N — Money For Nothing. This is where I learned how commercial incentives quietly shape what people are shown.
- Three times in the Deloitte Technology Fast 50, and an FD Gazellen Award
- 40,000+ websites, 10,000+ affiliates and 400+ programmes
- ~€20M in net sales (2010), the year before the acquisition
- An engineering team of 15 inside a 60-person company
- Exited through a sale to Zanox (Axel Springer) in 2011
- Affiliate network
- Custom platform
/llms.txt
Built with AI, on purpose
This site is itself the argument. It was specified, built, reviewed and shipped with Claude Code — design document first, then an implementation plan, then code, then verification. The spec and the full commit history live in the repository.
- A design document written and approved before a single line of code
- All copy in one typed content file — the build fails if a translation is missing
- No animation library: CSS keyframes and one IntersectionObserver
- A machine-readable summary at /llms.txt, for the agents that read this next
About
Klaas Joosten
Founder · Interim CEO/CTO · AI product and process leader
My worldview was formed in Tanzania, where my parents did medical and development work. It made one thing obvious early: build systems that do good at scale, or do not bother building them.
Severe dyslexia was supposed to be the obstacle. It became the training: simplify radically, impose structure and separate signal from noise. Those habits now shape how I make products, processes and teams understandable.
The rest is endurance. Weissensee on skates, Nereus on the water, Mont Ventoux on two wheels. Refereeing amateur football and field hockey taught me the other half: make fair decisions under pressure, explain them clearly and keep the game moving.
Those who dare to jump
learn to fly
Get in touch
Available for interim CEO/CTO, product leadership and AI-transformation roles where business, process and technical execution need to move together.
How that usually looks
- CEOs and leadership teams
- Interim CEO/CTO · Product leadership
- Turning a commercial opportunity or stalled process into a product and an organization that can deliver it.
- Recruiters
- CEO · Product · AI transformation
- Founder-level leadership with a track record in platforms, marketplaces, funding, teams and exits.
- Interim and transformation managers
- Product and process partner
- Connecting business decisions, specialists and AI-enabled execution inside a wider transformation.