Mattermost: Self-Hosted Slack Alternative with Corey Hulen

Software companies today rely on group chat applications.

The world of startups and small businesses is dominated by Slack. But for some large enterprises, regulatory constraints prevent them from using Slack. Slack is a web application that is hosted in the cloud, and regulated industries such as banking often need to run their applications on their own on-prem infrastructure.

Mattermost is an open source alternative to Slack that can be self-hosted. This means that all of the networking complexities and scalability challenges that are controlled in the cloud by Slack need to be handled by open source code rather than managed services running in the cloud.

Because it is open source, Mattermost can also be redesigned and customized. Uber designed their own custom version of Mattermost called uChat.

Corey Hulen is a co-founder and the CTO of Mattermost. He joins the show to discuss the motivation for building Mattermost and the engineering challenges of building an open source chat system.

For more episodes about building chat systems, we’ve done several shows about Slack, covering the engineering, security, and chat system.


Transcript provided by We Edit Podcasts. Software Engineering Daily listeners can go to to get 20% off the first two months of audio editing and transcription services. Thanks to We Edit Podcasts for partnering with SE Daily. Please click here to view this show’s transcript.


Mesosphere’s Kubernetes-as-a-service provides single-click Kubernetes deployment with simple management, security features, and high availability to make your Kubernetes deployment easy. To find out how Mesosphere Kubernetes-as-a-Service can help you easily deploy Kubernetes, check out today.

Manifold makes your life easier by providing a single workflow to organize your services, connect your integrations, and share with your team. While Manifold is completely free to use, if you head over to you’ll get a coupon code for $10 which you can use to try out any service on the Manifold marketplace.

Logi Analytics provides embedded business intelligence that goes beyond dashboards and reports. Create, deploy, and constantly improve analytic applications that engage users and drive revenue. You focus on building the best applications for your users, while Logi gets you there faster and keeps you competitive. Logi is a powerful yet nearly invisible business intelligence solution. Check it out by going to

Get ready to build content-rich websites and professional web applications with Wix Code. Store and manage unlimited data with built-in databases, create dynamic pages, make custom forms and take full control of your site’s functionality with Wix Code APIs and JavaScript. Plus, now you can get 10-percent off your Premium plan. Go to

Software Weekly

Software Weekly

Subscribe to Software Weekly, a curated weekly newsletter featuring the best and newest from the software engineering community.