Was waiting for them to get to the "why is it so complex" part, but after all the details of Cloudflare Pages, Cloudflare R2, Cloudflare Workers, Cloudflare Access, EC2 instances, multiple CDNs, hosted Redis, Nomad, Pulumi, web of proxies and APIs and front doors, a dozen microservices and an IaaS repo to make sense of all of this, it came down to:
> In total, we store over 150GiB of data, transfer over 6TiB of data monthly, have more than 10M requests a month, and serve thousands of unique visitors every week.
Basically my MacBook Pro from 2019 could host all their infra and data and serve the entire load (~3 RPS) with room to spare for my day-to-day work.
For anyone else who is reading the post looking to get inspired – ignore everything they did and start small. A single web service to handle all business logic, hosted on two rented VPS instances which split traffic. Data stored in mysql or postgres with some regular backup. Start scaling only when the load from this setup overwhelms you (and I can guarantee it won't for 99.9% of cases, including the one in this post).