“With other products you've got to convince people to give it a go. With Slack we've got to convince people to convince their teams to give it a try. So there’s this high inertia to overcome. The more that we do around supporting people trying out the product with their team, the more support we can give them, I think the more successful they'll be,” Henderson says.
From humble beginnings, Slack now operates offices in San Francisco (where it’s headquarters are located), New York (where Henderson spends most of his time), Vancouver, Toronto, Dublin, London, Tokyo and Melbourne.
The company has a valuation in excess of US$5 billion.
“We've had to redo the process of how we do everything over and over again as the organisation grows. That still remains our biggest challenge and I think the hardest is to just grow at the rate we've been growing which has been tremendous over the last few years,” Henderson says.
In January last year, Slack launched Enterprise Grid, a version of its product that fixed many of the issues that come with using Slack at scale. The main features allow administrators to set-up teams with their own centrally managed Slack instance, which can then be linked together using shared channels.
Since then more features have been added like app-management and user on-boarding tools and a suite of compliance, change control and security functions – anything to make sure “we can tick all those boxes that are just hard requirements to be able to roll out something like that in the enterprise,” Henderson says.
“Because we deliver software-as-a-Service we can’t ever take the service down or take six months to rebuild it. So refitting the engine without stopping the car has been…an experience as well,” he adds.
With feet now firmly in the enterprise space – with 150 customers including Capital One, Target, 21st Century Fox, Condé Nast using Grid – Slack is facing far bigger competitors than ever before.
There is Facebook Workplace (Henderson doesn’t consider them a competitor, it’s “more of the company watercooler than for getting your work done” he says), Google’s G Suite and Atlassian’s Stride (made publically available in March).
The biggest threat, however, probably comes from Microsoft’s Teams which went live at the start of last year.
While Slack relies on organic growth within a company, starting with a handful of employees, Microsoft (which reportedly considered paying $8 billion to acquire Slack)simply made Teams available to all Office 365 subscribers with Business Essentials, Business Premium and Enterprise plans.
“Definitely they have the advantage of massive distribution and a massive salesforce, but what we've increasingly seen over the last decade is that most enterprises are a Microsoft customer because they need Excel and maybe they need Outlook, but that hasn't stopped the rest of the SaaS world from continuing to grow and grow,” Henderson says.
“The landscape has opened towards multi-vendor software delivery. I think that definitely gives us a chance to be successful,” he added.
Slack has some other advantages, Henderson says, like the huge amount of knowledge it has on how people use the service and a greater willingness to integrate with third party applications.
“Our goal isn't to get an enterprise to buy a bunch of licenses, it is to have everybody at the company use it every day to get their work done…That’s not the default stance of most enterprise software makers,” he adds.
For now at least, the numbers, both paying users and daily users are on Slack’s side – and by some way. Henderson’s focus continues to be on making Slack the very best it can be. Oh, and maybe a game – third time lucky?
“The dream is to continue to work on games. I don't think that can ever be a business, especially in the way that we wanted to turn it into a business before and failed,” says Henderson, a fan of minimalist text game A Dark Room. “When I have some time I’m definitely going to create a game and finish it and it’s going to be great!”