Slack’s Cal Henderson: ‘Next year, 50pc of workers will be millennials’

6 Nov 2018

Slack CTO and co-founder Cal Henderson. Image: Slack

From a failed games company to the work tool of a generation in less than six years, Slack co-founder and CTO Cal Henderson says the company is only getting started.

Cal Henderson, the co-founder and CTO of Slack, doesn’t hold back. Dressed in his customary all-year-round chequered summer shirt and shorts, the English native’s feelings on Brexit are typical of his generation.

“It’s a fucking disaster. It’s so embarrassing that there was even a vote about it. Nobody wanted it to succeed; it was just sabre-rattling that went badly wrong. I am super-glad we put our European headquarters in Ireland. My sons would have been able to live and work anywhere in Europe, but now who knows? It has closed off a ton of options because of a vote that was made mostly by people who won’t be around to lose those options. It’s the same in the US, old people love to vote and young people love to be angry but yet don’t do anything about it.”

‘We are at 8m daily actives today and I think the widest possible audience for us is really all knowledge workers, and there are 600m of them and that’s continuing to grow globally’

Fatherhood can make a man reflective and Henderson is now on baby number two. Juggling a growth family and growth company, he has reason to be more reflective than most. “All of my children are demanding, in different ways,” he said, smiling brightly.

Slack has become the work tool that defines a generation. With 8m users, it is being deployed by some of the world’s biggest companies. Rescued from the embers of a failed game company called Glitch, the messaging tool used by a team of entrepreneurs and developers has gone on to to shape the workplace of today and most likely tomorrow.

Giving voice to a generation

In recent weeks, the company reached a $7.1bn valuation after completing a Series H funding round worth $427m. Reports signal that the company is ramping up for an IPO, potentially in the first quarter of 2019.

‘Slack is no longer a tool used by a small group of people like interns. It is actually the workforce’

Slack was founded by Stewart Butterfield, Cal Henderson, Eric Costello and Serguei Mourachov after they shuttered Glitch. The same team was also involved in the creation of Flickr, the photo-sharing platform acquired by Yahoo in 2005.

“I wouldn’t recommend having a growth company like Slack and a growth family at the same time [but] it is very focusing. It has really caused me to pay attention to how I spend my time; I have to separate work, making sure I carve out time with my family.”

This focus and situation means that Henderson and his colleagues have not only crafted the tool that a generation wants and needs, and that is an antidote to tech traditionally prescribed by CIOs, but they are that generation, too. “It has definitely reinforced being able to have a good work-life balance. Within the next year, 50pc of the global workforce is going to be millennials. They are no longer a small group of people working as interns. Millennials are the workforce.”

Slack’s initial freemium model saw it being gradually introduced by a generation of workers valuing communication and getting the job done over enthusiasm-sapping fiefdoms, silos and politics. That gentle introduction has become a flood. According to Slack’s latest figures, there are now more than 8m daily active users across more than 500,000 organisations that use the platform. The company has more than 3m paid users and 65pc of companies in the Fortune 100 are paid Slack users. More than 70,000 paid teams with thousands of active users connect in Slack channels across departments, borders and oceans.

Its smooth interface and robust platform make it perfect for teamwork collaboration and document-sharing, and it has become the destination for integration with many other apps and work tools. But will it ever bring about an end to the tyranny of email?

“Email is never going to die completely. Long-term, it is the cockroach of the internet; nobody likes it but it is impossible to eradicate. Email addresses will be around indefinitely. But I think what is going to happen is … more and more use cases, which email isn’t suited to, will move away. If you look at the standard inbox on email today, it is a mix between that internal and external communication, friends and family, spam, marketing messages.

“It’s a product that has been in the workforce for 30 years and isn’t scaling to the level of communication people have in the workplace now. As more and more information work becomes teamwork, and collaboration is at the core of that, email is not the right tool for that kind of communication.”

Integration is everything

Slack begins with internal communication but it is increasingly a hub for a myriad of software-as-a-service (SaaS) applications. “Integration is a key piece of the functionality of Slack,” Henderson explained.

“Over the last decade, we’ve seen this explosion in SaaS … the rise of Amazon Web Services (AWS) and infrastructure as a service. All of this has meant that there is a lower barrier to entry to create SaaS businesses, especially for more and more niche business cases. So, while you get the broadly applicable things like calendaring, Google Docs, Dropbox that can be used by any job function, increasingly you get a very specialised kind of financial forecasting tool or marketing email automation or something to do with sales lead-scoring in a particular way. And more and more products are getting more and more focused on individual productivity in a bunch of different roles, and we are seeing organisations using Slack as the collaboration hub for those. To pull all of those together is really powerful.

“When you think about how work happens in organisations, medium-sized companies are now buying software from more than 100 vendors and, as companies get larger, it is many hundreds. A worker might get a request that comes in from a customer at Zendesk and have customer records at Salesforce and Google Docs, a Jira ticket or a GitHub commit, and all of that information about work is happening in all of these different, disparate systems. If you can bring those together in the context of a Slack channel, you get the whole context of the work that is happening, the genesis of that work, the iteration that happens on it, a paper trail.

“A big part of the value of Slack is that you have that record to come back to. You can see not just the discussion, but the artefacts that discussion was around. When you come back later, you can see the Google Docs, the Salesforce records, Jira tickets, and tie all of those together.”

The responsibility of running a tool that is beloved by millions of daily users is not lost on Henderson and a brief outage in September was reported in the world’s media as some kind of a hipster meltdown. Henderson said the key is to realise that Slack is a utility, not just a technology. “Unlike a lot of tools used in the workplace, if Slack is down for even a few minutes, you can feel that.

“We strive to maintain the kind of service that customers expect of us and we are investing very heavily on the reliability infrastructure side of it to be able to continue to provide that service as we grow very fast, and also make changes to the product and continue to add integrations and capabilities.

“But, first and foremost, customers need that to be always working. We want our customers to treat it like a utility like electricity rather than another piece of software they use.

“We are making a lot of investment in infrastructure and processes. We look to how utility companies operate, like electricity, telecoms, airlines and more. This is infrastructure that has to work all the time, it is a different approach, it is a level of service above where enterprise software needs to be. If Slack is down for the afternoon, your business grinds to a halt. You need to provide that very top tier of service.”

Slack is a verb for the modern worker

The impact of Henderson and his colleagues at Slack on the working world and on today’s culture is best summed up by the fact that ‘I’ll Slack that to you’ is part of most workers’ daily lexicon.

Henderson himself gets a thrill when he sees it being used out in the wild, like on a laptop in a café in London or on a smartphone on a subway in New York. For someone who has made a dent in the working universe, he enjoys a degree of anonymity in his native UK.

Not only that, but Slack has kicked the hornet’s nest of competition, with enterprise software giant Microsoft creating a Slack-like product called Teams and Facebook having its own take on collaboration with Workplace.

Henderson believes competition is a healthy thing. “It is very validating when a player as big as Microsoft creates a product that is very similar. It signals to us and to the market that this is a real category, and it is going to be around a decade from now.”

Henderson is fired up about where Slack will go next. “We are at 8m daily actives today and I think the widest possible audience for us is really all knowledge workers, and there are 600m of them and that’s continuing to grow globally.

“We are at a little over 1pc of where we want to get to, but I think that it is a very exciting time because working at Slack means you can be part of a generation-defining product in terms of how work in the workplace has changed, and that is hugely exciting to have that kind of impact.

“It is not like solving world hunger or anything, but making people happier in the workplace and more efficient is a really nice goal. It’s a really straightforward company to work for in that sense, but 1pc of 600m means there’s plenty of legroom.”

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years