Keyword here is "automated". Quoting, "In the end, the Verve design, implementation, and verification described in this paper took just 9 person-months, spread

Keyword here is "automated". Quoting, "In the end, the Verve design, implementation, and verification described in this paper took just 9 person-months, spread between two people". This is considerably less than, say, seL4, which took 20 person-years(!). Well, seL4 is larger than Verve, but still.