Slack co-founder and CTO Cal HendersonSource: SlackLONDON — Slack co-founder and chief technology officer Cal Henderson said Wednesday that he had his doubts about whether companies could work from home before the coronavirus pandemic. “I was definitely a remote work, like fully distributed work, skeptic prior to this year,” said Henderson, whose platform facilitates working from home, in a virtual interview at the Web Summit technology conference.”I was as surprised as anyone that we were able to be so productive during that shift,” he said. “We were already distributed because we have offices around the world, but we weren’t fully distributed. Teams in general are co-located. They are in the same office and they can have in person meetings and whiteboarding sessions and all that kind of interaction.”The Microsoft Teams rival closed its offices and asked people to work from home at the beginning of March before shelter-in-place measures were introduced in California.”It felt like it was just a short-term thing … we weren’t going to be in this for months,” he said. “In many ways it felt like it was a snow day. Now, obviously it turned out to not be true.”Henderson said if he’d been asked a month prior to Slack shutting its office whether he thought it would be possible for large organizations to go remote overnight, he would have said no. “Organizations can’t be productive like that at scale,” he said. “It would just be an impossible undertaking.”Slack announced on Monday that it is being acquired by enterprise software giant Salesforce for $27.7 billion.By acquiring Slack, a business chat service with over 130,000 paid customers, Salesforce is bolstering its portfolio of enterprise applications and filling out its broader software suite as it seeks new areas of growth.Slack’s annual revenue topped $100 million by early 2017 and reached $400 million two years later. The shares debuted on the New York Stock Exchange in June 2019, through a direct listing.The stock, which opened at $38.50, has been on a roller coaster since, trading near $17 in March of this year, before climbing back close to $40 in June and then dropping back below $25 in mid-November.— CNBC’s Ari Levy contributed to this article.