While AI disruption looms over many legacy SaaS companies, several HR tech startups seem to be thriving. One of these companies is small-business payroll provider Gusto. The 14-year-old company, last valued at over $9 billion, just announced that it surpassed $1 billion in revenue earlier this year. Unlike many startups that report annualized recurring revenue (ARR) — an estimate of the value of their contracts in the upcoming 12 months — Gusto’s figure represents actual revenue earned over the previous 12 months. Gusto was last valued at $9.3 billion , Fortune reported, when it launched a $200 million tender offer for its employees in June 2025. The deal valued the company about where it was valued in early 2022 . That’s a bargain for Gusto investors compared to its decacorn competitors. For instance, Deel, which serves large international businesses, crossed $1 billion in ARR last year.…