We at Moesif (https://www.moesif.com/solutions/track-third-party-api) released a similar tool in 2017 and found that many of our customers including Deloitte, UPS, Snap Kitchen, iFit, and Trung's previous company, Snap Kitchen were looking for a way to track APIs without the complexity of a full service mesh like Envoy. Especially if you're hosted in something that cannot run an on-prem service mesh or gateway.
We're a little different in that we also support agent-based rather than just proxy. Meaning we have an SDK that sits out-of-band.
I prefer REST especially for public/external APIs. It's more empathetic towards third party developers who may not be as intimate with your API as your internal team. For example, much easier to reason a few well-understood entities like items, users, and orders if I was building an e-commerce API then a list of RPC operations. I would add GraphQL can also be easier to understand as long as the entity relations make sense. Lot's of exciting stuff happening in the GraphQL world but it does have disadvantages also.
We have multiple roles open in San Francisco and remote:
Senior Software Engineer https://apply.workable.com/moesif/j/86483B715B/
Enterprise Sales Development Representative https://apply.workable.com/moesif/j/5E13A09868/