[ojeggplant]

If I was making 34k a year after 13 years on ANY job in the USA, I'd get off Hacker News ASAP and make changes in my life so that it doesn't reach 14 years.

As an answer to your original question, Gusto's CTO responded in the question above yours. His answer below:

Co-founder and CTO of Gusto here. This is a REALLY good question and something that’s hard to appreciate until you actually to build a payroll system. I think a common misnomer is that if you’re not doing ML/AI/AR/blockchain/[insert latest technology here], you’re not doing R&D. The domain of Payroll turns out to be an incredible complex business domain. I think Ron Jeffries says it best in his post: http://wiki.c2.com/?WhyIsPayrollHard The software design of such a complex business domain at scale turns out to be an incredibly hard engineering challenge, and something that is often overlooked when we think about big engineering challenges. A little known fact is XP and Agile were developed by Kent Beck while working on a Payroll system for Chrysler (In fact, Kent now works at Gusto to help us with our payroll system).