How This Vector Database Startup Raised $70M

The Myth of the Fundraising Roadshow

Founders are taught that fundraising is a sales process. You build a list, create a deck, send hundreds of emails, and brace for a grueling roadshow of back-to-back meetings, hoping to close a round before you run out of cash.

Bob van Luijt, cofounder of the AI search platform Weaviate, proves there’s another way. His company raised $70 million, all the way through a Series B, by doing the exact opposite. They focused entirely on building their product in public, fostering an open-source community, and let investors come to them.

In fact, the one time they tried a traditional pitching roadshow, it yielded zero dollars. All their funding came from inbound. This isn't luck; it's a playbook. It's called organic fundraising, and for a certain class of company—especially in deep tech or open source—it’s far more effective than chasing VCs.

The Organic Fundraising Flywheel: A Step-by-Step Guide

Instead of thinking of fundraising as a separate, discrete activity, think of it as the natural output of building a great company and community. The model looks like this: Build in Public -> Attract a Community -> Generate Inbound Interest -> Close Funding.

Step 1: Start with an Open-Source Core

Weaviate began as an open-source project to explore a new way to search and store data in machine learning models. Van Luijt and his cofounder didn't start with a business plan; they started by solving a technical problem and sharing the solution.

For a technical founder, open source is the ultimate form of "showing, not telling." It does three things traditional pitching can't:

De-risks the technology: Investors don't have to take your word that your tech works. They can see the code, the activity, and the contributions from other developers. It’s the ultimate technical due diligence. · Builds a distribution channel: A community of developers and users becomes your sales and marketing team. They advocate for your product inside their own companies. · Proves early market validation: When developers voluntarily use your tool, it’s a powerful signal of product-market fit long before you have revenue.

Step 2: Turn Your Product into a Community

Weaviate didn't just dump code on GitHub. They actively cultivated a community around it. This is the critical step where most founders fail. A community isn’t a mailing list; it’s a living ecosystem.

Be present where your users are: Whether it’s Slack, Discord, Twitter, or a niche forum, be there to answer questions, debug issues, and listen to feedback. · Create valuable content: Write blog posts, create tutorials, and host webinars that help people solve problems using your tool. This positions you as a leader in your space. · Measure what matters: While GitHub stars are a vanity metric, investors do look at them. More importantly, they look for signals of a healthy community: number of contributors, pull requests, Slack/Discord channel activity, and the quality of the discussions.

Before their Series A, Weaviate had a burgeoning community of developers using their tool. This social proof was more powerful than any deck. Investors could see for themselves that something special was happening.

Step 3: Let Inbound Come to You

When you build a valuable public resource and a thriving community, investors will find you. VCs are constantly monitoring platforms like GitHub and talking to developers to find the next big thing. An active open-source project is a flashing beacon of opportunity.

Weaviate’s journey is a testament to this. Their seed and Series A rounds came from investors who saw the traction and reached out. The conversation changes completely when an investor initiates contact. It’s no longer a pitch; it’s a discussion about how they can join what you’re already building.

Common Founder Mistakes in Organic Fundraising

This strategy isn't magic. It requires discipline and avoiding common pitfalls.

Mistake 1: Confusing "Open Source" with "No Commercial Strategy"

Organic fundraising doesn’t mean you don’t need a business model. Weaviate was built on an open-source foundation, but they launched their commercial entity in 2019 with a clear plan to offer paid services, support, and enterprise-grade features around the core product. You must have a clear answer to "How will you make money?" from day one.

Open Core: The core product is free, but advanced features for enterprise use (e.g., security, admin controls) are paid. · Managed Services: You offer a paid, hosted cloud version of your open-source product. · Support & Services: You sell support contracts, training, and custom development to large companies using your tool.

Mistake 2: Failing to Tell the Story

Even with inbound interest, you still need a compelling narrative. As van Luijt notes, being able to capture the essence of what you are doing in 15 to 20 slides is key. Your deck should connect the dots for the investor:

Slide 1: The Community: Show the GitHub stats, the community growth, the logos of companies where developers are using your tool. · Slide 2: The Commercial Opportunity: Explain your business model. Show the path from a free developer user to a multi-million dollar enterprise contract. · Slide 3: The Vision: Paint the big picture. For Weaviate, it was about revolutionizing how we interact with data in the age of AI. The open-source project was just the first step.

Mistake 3: Building a Global Team Without a Global Culture

Weaviate was 100% remote from its inception in 2019, long before it was fashionable. This allowed them to hire the best talent from a global pool of 12+ nationalities. A remote-first setup is a superpower for an open-source company, as your talent pool is as distributed as your user base.

However, this requires intentionally building a remote culture. It's not just about letting people work from home. It means asynchronous communication, excellent documentation, and deliberate efforts to build team cohesion across time zones.

How to Apply This This Week

You don’t need to have a massive open-source project to start fundraising organically.

Start Building in Public: This week, take one piece of internal tooling, a useful script, or a clever insight and share it in a blog post or on GitHub. Start building a reputation as someone who provides value. · Map Your Flywheel: Sketch out your own organic growth loop. What can you build? Where can you share it? Who is the community you need to attract? What is the commercial model? · Audit Your Community Footprint: Where do your potential users hang out online? Make a list of 5 subreddits, Discords, or forums. Spend 30 minutes a day there this week, listening and helping—not selling. · Define Your Commercial Layer: If you already have an open-source project, write down a one-page document outlining your path to revenue. Be brutally honest. Would you pay for this?

The path Weaviate took isn’t for everyone. But it’s a powerful reminder that the best way to get an investor’s attention is to build something people—especially developers—genuinely want. Build a community, not just a pitch deck.