I guess I'm confused, if you're already running Cloudfront, API Gateway, and lambdas, why you'd bother to make API calls out to Sheets rather than just plunking down a simple DynamoDB? Maybe the data access patterns are more complicated than I'm thinking, or just to capture the built in Forms -> Sheets data entry flow?
Co-founder here. Cloudfront, API Gateway and lambda all came a bit later (weeks to months later). They were incremental improvements and quite easy to set-up. Sure we could have used DynamoDB or any other database but in practice you never just need a database.
Sheets gives us an admin tool, BI tool, Charting, 'ETL', simple schema changes, etc. all-in-one.
Note we actually still use Google Sheets for some things like storing the list of companies. Just today, I needed a quick way to summarize the description of each company into a few words. I installed an add-on for =GPT() formula. Within a few minutes I had done ETL, column addition, made API calls, etc. 0 code.
