Like all small companies, Obvious is attempting to minimize expenses as much as possible in order to extend our financial "runway" for as long as possible. We are frugal, but we are not "frupid" (frugal + stupid). Most of our expenses, over 65% typically, are people-related: salaries, contractor expenses and benefits.
The founders have Obvious business debit cards; if you need to purchase something, just ask one of us.
When you book travel, please use Cleartrip/Makemytrip or a similar service and look for good fares. If you have a long flight, it's OK to book an "extra room" seat in coach so that you can get work done. We don't do business or first class. Don't eat at super-fancy 4-star restaurants or take fancy cars everywhere. Just be reasonable.
Online services that save us time and effort are totally worth the money. We subscribe to a bunch of them: GitHub, Slack, Zeplin, Figma, G Suite, Digital Ocean, Timetastic... to name a few.