HubSpot was founded in 2006 in Cambridge, Mass., and went public in 2014. It’s one of those slick, fast-growing start-ups that are so much in the news these days, with the beanbag chairs and unlimited vacation — a corporate utopia where there is no need for work-life balance because work is life and life is work. Imagine a frat house mixed with a kindergarten mixed with Scientology, and you have an idea of what it’s like. It turned out I’d joined a digital sweatshop, where people were packed into huge rooms, side by side, at long tables. Instead of hunching over sewing machines, they stared into laptops or barked into headsets, selling software.