Thierry Schellenbach co-founded Stream after struggling to scale activity feeds

Stream Co-founder & CTO Tommaso Barbugli (left) and Co-founder & CEO Thierry Schellenbach (right)

HackerNoon Reporter: Please tell us briefly about your background.

I grew up in the Netherlands, and I was interested in technology from a young age. I started a gaming website when I was 13. Later, I attended Erasmus University Rotterdam before founding Fashiolista, my first startup and an early social network similar to Pinterest. It grew to millions of users and we learned the hard way that building apps that scale is challenging. That was part of the inspiration for starting Stream. Stream is an API for building activity feeds and chat that’s used by some of the world’s largest apps.

What's your startup called? And in a sentence or two, what does it do?

Stream provides components for product teams to add chat or activity feeds to their apps. Our scalable APIs and SDKs make it easy for software teams to add in-app chat and activity feeds without reinventing the wheel.

What is the origin story?

At Fashiolista, we struggled with scaling the activity feed as the social network grew to millions of users. Even companies such as Twitter and Facebook shared this challenge, and that’s what inspired me and my co-founder, Tommaso Barbugli, to start Stream. It was about solving a personal pain point that we knew other companies were struggling with too.

Not too long after we started working on the technology and founded the company, we participated in Techstars NYC in 2015 and moved our headquarters from Amsterdam to Boulder, Colo. It was a snowball effect from there: we evolved the company and introduced our chat product, grew our customer base exponentially, closed our Series A and Series B funding rounds, and scaled the team. Over a billion end users rely on Stream’s APIs nowadays, so the odds are pretty high that some of the apps on your phone are using our tech.

What do you love about your team, and why are you the ones to solve this problem?

Our team is passionate about tackling difficult tech problems at scale and creating reusable components for them that allow product owners to ship apps faster, more securely, and with a better user experience.

More than 25 nationalities collaborate on Stream’s products, and that shared purpose unites us, brings our diverse backgrounds and talents together, and helps us to improve in-app experiences across a broad range of industries worldwide.

If you weren’t building your startup, what would you be doing?

I like building open source software. Joining a Series A or B-stage startup could also be fun since the compensation is excellent and it’s relatively stress-free compared to starting something from scratch.

At the moment, how do you measure success? What are your core metrics?

Aside from typical (but essential) growth-stage metrics such as annual recurring revenue and year-over-year growth, we’re also focused on our Net Promoter Score (NPS), which measures customer satisfaction. Ultimately, a high and healthy NPS signals customer retention and is a good indicator of a company’s future growth potential.

What’s most exciting about your traction to date?

Stream powers chat and activity feed experiences for more than a billion end users globally, which means there’s a good chance several of the apps on your phone utilize our technology. It’s exciting to see that impact, and I’ll never get tired of encountering our technology in my own daily life. For example, I recently attended a virtual event and discovered it was hosted on a platform using our chat API. I spend a lot of time focused on our growth metrics, so seeing the traction in a new light that way is fuel to keep pushing forward.

What technologies are you currently most excited about, and most worried about? And why?

APIs and SDKs are revolutionizing software development, and it’s exciting to see the component-based approach gain momentum and increase efficiency for teams. It's a bigger trend, and cloud hosting continues to grow rapidly, along with higher-level services like Algolia for search, Mapbox for maps, Radar for location data, and Commerce Layer for commerce.

However, product teams need to be able to rely on third-party APIs, so there is pressure for those providers to deliver in terms of reliability and performance. These are things that are hard to see on the outside, but at Stream, we spend a ton of resources on high availability and performance optimization. For example, we just introduced our Edge API Infrastructure for chat to further improve performance, and we run our own RocksDB storage engine to optimize performance.

What drew you to get published on HackerNoon? What do you like most about our platform?

HackerNoon covers the topics that tech professionals and developers care about. It’s a relatable, honest, and inclusive platform.

What advice would you give to the 21-year-old version of yourself?

Paul Graham wrote about the importance of design, marketing, and engineering, and he recommended mastering two out of three. I believe those three functions are essential for any new startup, and if I could give advice to my younger self, it would be to follow that philosophy earlier and pick two.

What is something surprising you've learned this year that your contemporaries would benefit from knowing?

We’ve started an in-house teaching effort at Stream focused on engineering under the leadership of Ian Douglas. I think more companies need to invest in training their team. Especially if you do something that’s technically hard like shipping activity feeds and chat for a billion end users. You can’t fully rely on hiring – it needs to be a combination of hiring and training.

Vote for Stream at Startups of the Year: Boulder