Why We Invested in Knock

A developer platform to solve the notification bell

David Sacks
Craft Ventures


Knock cofounders Chris Bell & Sam Seely

We’re excited to announce that Craft has led the $12 million Series A in Knock, the notification infrastructure platform for engineering and product teams.

We’re all familiar with the notification bell. It’s ubiquitous across social media and SaaS apps. Notifications have become the standard way to keep users active and engaged over time. But what’s powering those notifications is typically haphazard code, hacked together as developers realize the need.

In time, application developers discover that they need a more robust notifications infrastructure — with the ability to quickly add new notification types, batch related notifications, manage notifications across multiple distribution channels, and set different rules for different segments of users. This is typically when developers realize that their homegrown system doesn’t scale and wish there was a way to outsource the problem instead of reinventing the wheel.

Enter Knock, which provides easy-to-use tools, APIs, and components for developers to manage notifications across channels, including in-app, push, email, SMS, and messaging app integrations like Slack.

Founders Sam Seely and Chris Bell experienced notification challenges first-hand as product and engineering leaders at their previous company Frame.io. To solve these problems, they built an organized and scalable notification system. Soon they decided to productize their solution as a separate company, founding Knock in January 2021. Since then, Knock has expanded into a fully-featured platform capable of serving customers ranging from startups to public companies.

Customers such as Amplitude, Vercel, and Webflow use Knock to power customer messaging without needing to build, maintain, and scale their own in-house notification system. Instead of diverting engineering resources from product development, Knock gives them a centralized hub for cross-channel notifications.

Knock’s API’s provide features and data management capabilities to orchestrate notifications across the major communication channels: email, push, messaging apps, SMS, and real-time in-product feeds

Despite being a more recent entrant in the category, we found that Knock consistently won competitive deals because of its superior developer experience, the ease of setup for dev teams, and its outstanding product documentation. Our conversations with Knock customers validated our belief in the product. They told us:

  • “We realized using Knock would save us hours and hours of dev work. Also, managing scenarios like batching just added complexity, and made it pretty easy for us to choose outsourcing this.”
  • “Our notification system was built internally and it was falling short…we realized it was going to take years and dedicated engineering resources to build and manage a new one for all the use cases we wanted. We were consistently surprised by Knock being the best provider, while being the youngest company we looked at.”
  • “It’s very important that notifications are well done. They’re critical to the user experience and therefore our business. Knock has better analytics and observability features. That was key for us.”

We believe that developers need a standard for notifications, which gives Knock the opportunity to become the central nervous system that orchestrates end-to-end user engagement for product and marketing teams.

Sam & Chris have an ambitious vision for Knock and have executed very well. This focus and execution, combined with their experience with this problem, make them exactly the type of founders we like to partner with at Craft. We are excited to help them dominate this category and ultimately change the way that software companies engage their users.



David Sacks
Craft Ventures

General Partner and Co-Founder of Craft Ventures. Previously: Founder/CEO of Yammer. Original COO of PayPal.