>> For sites of any complexity with any dynamic content having CDN redundancy is akin to being multi-cloud — it is not worth the effort.

I proposed and lead our multi-CDN project at Pinterest for both static and dynamic content and I can tell you, many many times over, it has been well worth the effort. Everybody should do this if not only for contract negotiating leverage.

Cache invalidation is fast enough on all CDNs now for most use cases (yes, including Akamai). But realistically, most sites (Pinterest included) are not using clever cache invalidation for dynamic content because it’s not worth the integration effort (and it’s very difficult to abstract for large 1k+ engineering teams). Most customers are just using DSAs for the L4/L5 benefits (both security and perf). In that case, it’s not complicated to implement multi-cdn.