Brian Nichols is the co-founder of Angel Squad, a community where you’ll learn how to angel invest and get a chance to invest as little as $1k into Hustle Fund's top performing early-stage startups.

I've been studying Stewart Butterfield investments for a while now, and here's what struck me: this isn't your typical operator-turned-investor story. Stewart built two massive companies (Flickr and Slack), sold both, and now he's writing checks into early-stage startups. But the way he thinks about investing is completely different from how most VCs operate.

Let me break down what I've learned and what it means for those of us writing checks at the pre-seed and seed stage.

Who is Stewart Butterfield?

If you don't know Stewart, here's the quick version: he co-founded Flickr in 2004, which Yahoo acquired for around $25 million. Then he built Slack, which went public in 2019 and was eventually acquired by Salesforce for $27.7 billion in 2021.

Yeah. Not a bad resume.

But here's the thing that makes Stewart's investing interesting. He's not running a fund. He's not trying to build a personal brand as an investor. He's just quietly writing checks into companies and founders he believes in, mostly as an angel investor and through small syndicate deals.

Looking at Stewart Butterfield investments over the past few years, you'll notice they're concentrated in specific areas where he has genuine expertise: collaboration tools, developer infrastructure, and companies rethinking how teams work together.

This is the first lesson: invest where you actually know something.

The "I've Actually Built This" Advantage

Here's what separates Stewart from most investors. When a founder pitches him on a collaboration tool or workplace software, he's sat in every seat at the table. He's been the founder building the product. He's been the CEO scaling the team. He's dealt with enterprise sales cycles. He's navigated IPO processes.

Most VCs, even experienced ones, haven't actually done the thing they're investing in.

At Hustle Fund, we see this all the time. The best investors in our network are former operators who bring real pattern recognition to their investments. They can spot the difference between a founder who's just winging it and one who actually understands their business deeply.

When you look at Stewart Butterfield investments, this expertise shows up in the types of companies he backs.

What Stewart Actually Invests In

Based on public information and various reports, Stewart has invested in companies like:

Tandem: A virtual office platform for remote teams. Makes sense, right? Stewart spent years thinking about how people collaborate digitally.

Assembled: Workforce management software for support teams. Again, this is someone who built a company that had to scale customer support massively.

All Turtles: A startup studio focused on AI products. Stewart was reportedly involved early on, bringing his product thinking to multiple ventures at once.

The pattern here? Stewart isn't randomly spray-and-pray investing. He's backing founders who are solving problems he's either experienced himself or deeply understands.

This is critical for early-stage investors. Your edge isn't just having capital. Your edge is having genuine insights into whether a founder is onto something real or chasing hype.

The "Future of Work" Thesis (Before It Was Trendy)

Stewart was thinking about remote work and digital collaboration long before COVID made it mainstream. Slack itself was built on the thesis that teams needed better ways to communicate than email.

Looking at Stewart Butterfield investments now, he's doubling down on this thesis. He's backing companies that assume distributed teams are the default, not the exception.

Why this matters: The best investors develop a point of view about where the world is going and invest accordingly. Stewart's not just reacting to trends. He's been living in the future of work for 15+ years.

For those of us investing at the early stage, this is a reminder to develop our own theses about what's changing in the world. Don't just invest in what's hot today. Invest in what you believe will be obvious in five years but seems contrarian now.

What Stewart Looks For in Founders

I've never personally talked to Stewart about his investment criteria, but based on interviews and his track record, a few patterns emerge:

Product obsession: Stewart is famously detail-oriented about product experience. He's looking for founders who sweat the small stuff and actually care about user experience, not just growth metrics.

Understanding distribution: Building a good product isn't enough. Stewart knows this better than anyone. Slack succeeded partly because they nailed their go-to-market strategy. He's going to ask founders hard questions about how they'll actually acquire customers.

Ability to pivot: Both Flickr and Slack were pivots from failed gaming companies. Stewart understands that the best founders are willing to change direction when the data tells them to.

This last point is huge and often misunderstood. Pivoting isn't about giving up. It's about being intellectually honest about what's working and what's not. Stewart has lived this multiple times.

The Anti-Hype Approach to Investing

Here's something I really appreciate about Stewart's approach: he's not chasing hype cycles. You won't find him leading rounds in the hot AI company that every other VC is fighting over.

Instead, Stewart Butterfield investments tend to be in companies solving real problems for real customers, often in unsexy categories like workforce management or internal tools.

This is actually where a lot of the best opportunities are in early-stage investing. Everyone wants to invest in the next consumer social app or breakthrough AI model. But the companies quietly building B2B tools for specific workflows often make better investments.

Why? Because they have clearer paths to revenue, more defensible moats, and less competition for deals.

What Stewart Knows About Enterprise Sales (That Most Investors Don't)

Slack's journey from beloved product to enterprise juggernaut taught Stewart some hard lessons about selling to big companies. These lessons show up in how he evaluates investments.

Bottom-up adoption isn't enough: Slack started with individual teams using it for free, but real revenue came from enterprise contracts. Stewart knows that viral growth is great, but you eventually need a real sales motion.

Switching costs matter: Once Slack was embedded in a company's workflow, it was incredibly hard to rip out. He's looking for products that become part of customers' daily routines.

Support and onboarding are products too: Scaling enterprise customers means having robust support systems. This isn't just an afterthought. It's core to the business model.

When you're evaluating early-stage companies, especially in B2B, these factors matter way more than most investors realize. Stewart gets this because he's lived it.

The Tactical Lessons for Early-Stage Investors

Okay, let's get practical. What can we actually learn from studying Stewart Butterfield investments?

1. Invest in your area of expertise: Stewart backs collaboration and workplace tools because that's what he knows. Don't invest in biotech if you've never worked in healthcare. Find the domains where you have genuine pattern recognition.

2. Product quality is non-negotiable: Slack succeeded partly because it was delightful to use. Stewart isn't going to back founders who ship mediocre products and plan to fix them later.

3. Look for second-time founders who learned from failure: Stewart's best work came after his failed gaming companies. He values founders who've been through the ringer and came out smarter.

4. Distribution is as important as product: Great products die every day because no one knows about them. Stewart evaluates go-to-market strategies as carefully as product vision.

5. Be patient with the right companies: Both Flickr and Slack took time to find product-market fit. Stewart knows that transformational companies aren't built overnight.

The Reality Check: What Stewart Doesn't Do

It's also worth noting what Stewart's investment approach isn't:

He's not writing dozens of checks a quarter trying to hit a home run through volume. He's selective and focused on areas where he can add real value.

He's not using investments to build his personal brand or grow his Twitter following. He's pretty low-key about his angel investing compared to other high-profile operators-turned-investors.

He's not investing in things just because they're trendy. You won't find him doing FOMO deals into hot rounds just to be on the cap table.

This discipline is something every early-stage investor should aspire to. It's easy to get caught up in the excitement of startup investing and start writing checks into everything. The best investors, like Stewart, are thoughtfully selective.

The Bottom Line on Stewart's Approach

Stewart Butterfield built two category-defining companies by obsessing over product quality, understanding distribution deeply, and being willing to pivot when needed. His investment approach reflects these same principles.

For early-stage investors, the lesson isn't to copy Stewart's specific strategy. It's to develop your own thesis based on genuine expertise, be selective about where you invest, and focus on adding real value to founders beyond just capital.

If you're interested in learning alongside other operators who are developing their own investment theses and getting access to early-stage deal flow, Angel Squad is where we're building a community of founders-turned-investors who are all figuring this out together while investing in Hustle Fund's top-performing startups.

The venture world needs more investors like Stewart who actually know what they're talking about.