IaaS, PaaS, SaaS: who takes the 2 a.m. call IaaS, PaaS and SaaS are not technology categories. They are a chart of who gets the phone call when something breaks at 2 a.m. That is the only framing that matters to a 40-person company. The rest is... Cloud Computing Cloud Services Features Hybrid Cloud IaaS Integration PaaS SaaS Scalability May 3, 2023