We're Building in Public. Here's Everything.
Two brothers-in-law, a handful of companies, one acquisition, and a growing suspicion we keep solving the same problems.
Written by: Friso Paping & Tim de Rooij
One of us is writing this with a product launch in three weeks that he’s not ready for. A digital identity vault going live at a public event. The plan is to launch “The Founding Hundred,” exclusive access for the first hundred people to sign up at €100 per month. A golden badge, early access, and the kind of FOMO we’re betting will get people moving. If we nail it, that’s €120K in annual revenue from day one. The product is still in progress. The website isn’t live yet. There’s no final decision on the consumer brand name. Scary? Sure. But we’ll take it as it comes.
That’s what building a business actually looks like. Not the polished version. The real one.
A few months ago, one of us called the other while setting up a new holding structure. “What accountant did you use for the BV again?” The same question had gone the other direction the week before, except that time it was about pricing tiers. The week before that, it was GTM sequencing. Different businesses, different markets, and yet every single week we were having the exact same conversation: “How did we do this last time?”
At some point the response was: “We need to stop calling each other and start writing this down.” And the reply: “Yeah, but properly this time.” That became The Blueishprint.
Who we are
Tim is 39. Friso is 33. We’re brothers-in-law, which means we didn’t choose to be family but we did choose to keep talking about business at every family dinner until everyone else left the table.
We’re not co-founders. We’re not building one thing together. We’re each starting our own businesses, in different markets, with different products. But our backgrounds are different enough that we keep filling in each other’s blind spots.
Tim has lived and worked across the US, Europe, and Asia. He’s built teams and delivered AI products across all of them and has this annoying ability to look at a business model and immediately spot the thing that doesn’t add up. Right now he’s building Third Vector, helping companies redesign their operations around agentic AI. Not adding tools to existing workflows, but rethinking how the work gets done.
Friso built Sentinels, an AI-powered transaction monitoring platform, and sold it to a strategic buyer. Eight years in total, from first pitch deck to acquisition integration and managing the post-acquisition phase. The product is now running at some of the largest financial institutions in the world. It was an incredibly fun ride with plenty of ups, downs, and more near-death experiences than we’d like to admit. The acquisition alone taught us more in six months of due diligence than in years of actually running the business.
Now Friso is building a digital identity vault. You store your personal data once, and when an institution needs something, you approve the request and the data flows over, verified and up to date. No more digging up passport scans. We’ll write a lot more about this one.
Between us we’ve started companies, raised tens of millions in funding, held roles at organizations we probably had no business being at, and survived enough mistakes to fill a very long spreadsheet. We both love building things. That’s the short version.
Introducing The Blueishprint
We’re both moving about ten times faster this time around. Partly because we’ve been here before and know which shortcuts are real and which ones will blow up in your face. Partly because of AI. The combination of experience and the tools available right now means we can build in months what used to take years.
So why keep all of this in our heads?
Most business content is either too abstract (”here are 7 principles of great leadership”) or too specific to someone else’s situation to be useful for yours. What actually helped us came from people who shared the messy middle. Not polished case studies from five years later, but real decisions, made in real time, before anyone knew how they’d turn out.
That’s The Blueishprint, which we’ll be publishing on Third Vector’s Substack.
Blue-ish-print. Because a blueprint implies you’ve got it all figured out. We don’t, and in the age of AI things are changing so fast that what we write today may become obsolete tomorrow.
And we won’t be the only ones writing. We’ll bring in co-authors who are building right now and have something specific to share. Every article comes with actual materials. The spreadsheet you can fill in that afternoon. The workshop agenda you can run with your team on Friday. We’ll share the actual tools we used. Prompts, Lucid charts, Claude skills, case studies. Not because we think our way is the only way, but because reading about a GTM strategy is useless if you can’t build one yourself the same afternoon.
The tightrope: product and GTM
Every time either of us starts a new business or project, the approach is roughly the same. You start with the basics: entity, legal, finance, tooling. Get those out of the way so they never become a bottleneck. Then you’re straight into the tightrope.
Product and GTM are a symbiosis. You can’t build something nobody wants, and you can’t sell something that doesn’t exist yet. They need equal attention. The problem is you can’t give them equal attention at the same time. Some weeks you’re deep in product, building, testing, iterating. Other weeks you’re all GTM, talking to people, running experiments, figuring out your channels. The skill isn’t doing both. The skill is knowing when to lean into one and pull back on the other without letting either one fall over.
In Dutch we call this koorddansen. Tightrope walking. And it’s the thing we see founders get wrong more than almost anything else. Either they build for months without talking to anyone, or they sell something they haven’t figured out how to deliver yet.
And the thing that ties all of it together is talking to prospects. That never stops. Every product decision, every GTM move comes back to what we heard in the last conversation. You can have the best frameworks in the world, but if you’re not talking to the people you’re building for, you’re guessing with extra steps.
The cadences need to line up. Operations, product, GTM. How often you review and plan, how fast you ship, how you find and close customers. When they’re out of sync you feel it immediately. You’re building something nobody asked for, or selling something that’s three sprints behind what you promised.
What’s coming
We’ve organized everything into four workstreams — GTM, Product, Finance, and Operations — all published under The Blueishprint.
GTM and Product start now. Finance and Operations will come when they become relevant. Every article comes with templates, prompts, and the actual tools we use. This isn’t a locked roadmap. If you tell us you want something else first, we’ll adjust.
Next week we kick off with getting your GTM strategy on paper. We’ll walk you through writing it, stress-testing it, and building the pipeline to actually execute it. From there the series goes into target lists, lead enrichment, CRM setup, sales sequences, and automated outreach.
The Product series starts with how we capture user feedback and turn it into shipped code, with AI doing most of the grunt work. We’ll share the full setup, from feedback intake to Linear tickets to deployment.
Beyond that: funding (do you actually need it), cap tables, hiring when AI has changed the game, and the personal stuff like how to actually take a holiday when you’re building a company.
The one we’re most looking forward to writing: “I Got Acquired in a Stock Deal. Here’s What Nobody Told Me.” Stock deal vs. cash deal, tax traps, earnout games, and everything that blindsided us. Almost nobody writes about this from the founder’s side.
How we write (and why process beats prompts)
Full transparency: one of us is dyslexic. For most of his career, writing was the last thing he’d volunteer for. AI changed that. We use AI to help us write, to turn messy thinking into clear sentences, to catch errors our brains skip over.
But the thing everyone gets wrong about AI right now? There’s an endless flood of articles about clever prompts and AI skills and “10x your productivity with this one trick.” Open deur, as we say in Dutch: garbage in, garbage out. A prompt is only as good as the thinking behind it. If you feed vague input into any tool, you get vague output.
AI helps us say it clearly. The thinking is ours. We mention this because we think more founders should talk about it. Using AI to write isn’t cheating. It’s a tool, like everything else. And it’s one of the reasons The Blueishprint exists at all.
The community
The Blueishprint isn’t a newsletter you read and forget about. We want to build something where founders and operators raise real questions and work through them together. Someone struggling with their pricing gets input from ten people who’ve been through it. The articles are just the start.
We have an open WhatsApp group you can join right now. It’s live, it’s messy, and people ask real questions in real time. No gatekeeping, no “premium tier.” Just people building things and helping each other figure it out.
Your turn
Here’s our question for you: what’s the one thing you’re stuck on right now in your business? The thing you keep circling back to but haven’t cracked yet. Drop it in the WhatsApp group, reply to this email, leave a comment. We’ll either write about it, or someone in the community already has an answer.
And if you know someone who’s in the middle of building something right now, send this their way. The more people in the conversation, the better the answers get.
See you next Tuesday.
— Friso & Tim
Images: Tristar Pictures, Ivan S (Pexels)