Marketing freelancer voor SaaS- en app-bedrijven

Engels / Nederlands Ik ben Bart Stemkens, marketing freelancer. Ik help SaaS- en app-bedrijven bij het bedenken én uitvoeren van marketingstrategieën gericht op zichtbaarheid, leads en gebruikers. Bij mij gaan strategie en praktijk hand in hand, van ads tot CRO, van roadmaps tot data. Al ruim 10 jaar werk ik voor start- en scaleups zoals Squla, StudyGo, KIMO en Valyuu, en corporates als Nationale Nederlanden en Nescafé.

Je kunt met mij inhuren voor een samenwerking vanaf 1 dag p/week:

• Uitrol van een specifiek project of feature
• Ontwikkelen en uitrol van marketingplan/roadmap
• Tijdelijke versterking als interim marketeer
• Aansturing van externe bureaus en specialisten

Wil weten of we samen kunnen werken? Boek een video call of neem direct contact op via 06 833 29 344.

Mijn specialisaties

Resultaten uitgelicht

Dit zijn enkele van de resultaten die ik behaalde bij mijn recente projecten. Hetzelfde zou ik voor jou kunnen betekenen.

• Studira groeide in 14 maanden van nul naar 5 000 betalende gebruikers met een 90 % trial-to-paid-conversie dankzij de acquisitiestrategie die ik uitwerkte. Lees de casus.
• KIMO bereikte 150 000 app-gebruikers in 10 landen na de implementatie van mijn acquisitieplan. Lees de casus.
• Bieden & Wonen schaalde via mijn groeistrategie het aantal franchiselocaties van 3 naar 10 binnen twee jaar. Lees de casus.
• Chirpley zag met de door mij ontworpen GTM-strategie 20 000 influencers aan boord komen in het eerste jaar. Lees de casus.

Maar cijfers vertellen natuurlijk maar de helft van het verhaal. Dit is hoe opdrachtgevers de samenwerking ervaren:

“Bart is a multi-skilled professional able to make your business grow. He can handle high levels of complexity, and is pleasant to work with at all times.”

— Rens, CEO @ KIMO

“With Bart, you have everything you need to grow and scale—no extra resources required. If you could clone him, you’d leave your competitors in the dust.”

— Sarah, Head of Growth @ Small Improvements

“Smart, pragmatic, hard-working, and a great guy to have around. Our intake doubled, and costs were cut in half. Bart takes initiative, makes decisions, and gets things done.”

— Marnix, Proposition Manager @ Nationale-Nederlanden

Klik hier voor meer testimonials

Kom in contact

Ik ga graag met je in gesprek om te kijken hoe we kunnen samenwerken. Boek een kennismaking of neem direct contact op via 06 833 29 344.

Spanish / English / Dutch

Hi, I’m Bart Stemkens. I turn strategy into weekly execution — from data to creative. With 10 years of experience, I plug into product teams and founders to move fast, test smart, and learn what actually drives growth.

What I do

I help founders & product teams get a grip on their marketing — by setting direction, creating actionable roadmaps, and executing weekly growth experiments.

I plug into your team 2 to 3 days a week. From there, I run growth experiments — across the stack: from data to creative, from ads to onboarding.

I handle most of the work myself. If something falls outside my scope — and AI can’t help — I bring in one of my trusted specialists.

For who I do it

In 95% of the cases, teams bring me in because:

• They’ve got growth ideas, but no system to test or prioritize them
• They need temporary marketing capacity — someone who can step in and adapt fast
• They’re stuck in tunnel vision and want a fresh perspective to move forward (the system and perspective come included)

In the other 5%, they haven’t found product-market fit yet. I don’t rule those out — but only if there’s urgency, grit, and a clear path to validation.

You’ll probably get value from working with me if:

1. You have something people genuinely want — and can prove it
2. You’re ambitious about becoming the best in your space
3. You have someone who can show up to a weekly check-in
4. You’re open to experiments flopping — as long as we learn fast

Testimonials

“Bart is a multi-skilled professional able to make your business grow. He can handle high levels of complexity, and is pleasant to work with at all times.”

— Rens, CEO @ KIMO

“With Bart, you have everything you need to grow and scale—no extra resources required. If you could clone him, you’d leave your competitors in the dust.”

— Sarah, Head of Growth @ Small Improvements

“Smart, pragmatic, hard-working, and a great guy to have around. Our intake doubled, and costs were cut in half. Bart takes initiative, makes decisions, and gets things done.”

— Marnix, Proposition Manager @ Nationale-Nederlanden

→ view all testimonials

Client cases

Squla (Edtech)

From zero to 5,000 paying users in 14 months — with 90% trial-to-paid conversion.

KIMO (AI learning platform)

150,000 onboarded users in 10 countries, with low CPA and improving D1 retention.

Bieden & Wonen (Proptech)

From 3 to 10 franchise offices, while cutting lead costs by 50%

→ view all cases

Get in contact

If the testimonials or cases weren’t enough to convince you to schedule a call, I’ve got one last move: send me your website and I’ll reply with one growth experiment you could run tomorrow. Free. No pitch. No strings.

Testimonials

Cases