Smash Notes
Cal Henderson
Episodes
Notes
GeekWire · Slack CTO Cal Henderson
-
What Does Slack CTO Cal Henderson Tell Startups to Optimize for First?
On GeekWire, Slack CTO Cal Henderson says that for almost any software company that is not already a giant, the first job is finding product-market fit quickly. Slack was not designed on day one for more than 10 million daily users. The first version put in people's hands was the wrong one, and the early years were spent learning which parts of a tool that worked for small engineering teams would work for everyone else. He warns that building for massive scale before that fit is addictive for an engineer and a way to get stuck. Cloud hosting is what made the fast loop possible. At Flickr, he says, they bought servers and racked them themselves.
-
What Apps Would Cal Henderson Like to See Build on Slack in the Future
How do you take software that you already use everyday, and use Slack to enrich the usage of those applications? Slack would like that, and they even have a Slack Fund to fund those.
-
What Does Cal Henderson Look for When Hiring for Slack
People you hire in week one of the company are very different from the people you should hire with 1500 employees. More and more work has become knowledge work, with ability to collaborate at its core.
-
Did Cal Henderson Break Into Stewart Butterfield's Mail?
Breaking-in is a strong term. Cal was just very interested in the game that Steward was building, so he changed the default admin password on Glit's mailing list to get some insights, with the intention to build an API on top of the game. It wasn't the greatest move, but it worked out at the time.
-
Can Artificial Intelligence Make Slack Better
AI can certainly make small interactions better, thereby making your whole experience better.
It will be a while until AI is able to make drastic improvements in our use of software, probably not until it can achieve human-level intelligence.
-
Did Cal Henderson Say Slack Can Switch Clouds?
GeekWire asks Slack CTO Cal Henderson whether a company at Slack's size can switch between Amazon Web Services and Google Cloud. He says the big clouds are more alike than they used to be, so a move is possible, and also a lot of work. As the service gets more complex, it depends on the small operational details of one provider, such as how a queue behaves under load or when it fails. Engineers build around those details. Broadly the services match. The cost is in the differences. Henderson adds that Slack would rather spend engineer time, which is expensive, on fast iteration than on keeping an easy exit to another cloud.
-
How Do You Stay Flexible While Paying Millions of Dollars to a Cloud Service Provider Like Amazon AWS
Opportunity cost and engineering time are super expensive, and it makes sense to optimize for those, rather than try and save costs on web services.
-
What Technologies Are You Using at Slack Today
Slack is focused on ways to make engineers more effective and productive, lowering the technical barrier for DevOps. The idea is that if a team could build a feature, they should also be able to support it.
By embracing the latest cloud technologies like Kubernetes, they are simplifying deployment and maintenance for the whole organization.
-
What Would Cal Henderson Skip If He Were Launching Slack Today?
Slack CTO Cal Henderson tells GeekWire that a Slack launched today would make fewer product mistakes, because the company now has the data. The cloud lesson is the one he cares about. He would move further up the stack, away from raw virtual machines and toward platform services, including Kubernetes and higher-level Amazon Web Services. The goal is to avoid undifferentiated work that every company does and that does not make Slack better at Slack. At Flickr, he says, a quarter to a third of the team's time went to that work: buying servers in Canada, talking to customs, racking them, then realizing they were short on network cables. Hosted services give that time back.
-
How Hard Was Growing Slack Without Amazon Cloud?
It would have been much-much harder. In his first company, Cal had to buy physical servers and manually drive and install them in data-centers, which sucked up a third of his time. Moving to infrastructure-as-a-service enabled a whole new generation of startups.
-
What Were the Key Technical Decisions by Cal Henderson Which Made Slack What It Is Today
It could be very addicting to dive deep into a technology and build something for massive scale, only to never see it come true. When starting Slack, the team was unconstrained by what the technology would become, instead they focused on finding the product market fit. The job was to build something that worked and to iterate fast.
-
Why Is Slack So Popular With More Than 10 Million Average Daily Users
Slack is bringing hundreds of different work applications under the same roof, enabling companies to use a unified interface for all their communications and data.
While email was built on a one-to-one model of communication where new information was pushed on you, Slack enabled a one-to-many pull model, where anyone can subscribe to any information of interest.
Information in email is only born once an account is opened, and is as good as destroyed once the email account is closed. Meanwhile, Slack enables information to live on forever, so new team members never start with an empty slate, nor is their knowledge lost with transition.
-
How Did Cal Henderson Meet the Slack Team
Cal Henderson has been working with the same set of people and co-founders for a few decades now. In 2000s they'd made a video game on the internet, which turned into Flickr and got acquired by Yahoo. A decade later they tried another online game called Glitch, which again did not work, but turned into Slack.