We were using Memcached for some time but had disabled it a little while ago though. We’ve now enabled Redis for our back-end object cache.
While there’s a free version (Redis Object Cache) available, we’ve opted for their paid Object Cache Pro. Both are compatible with Cloudflare’s APO.
While we may be tuning and adjusting some of its configurations over the next while, from my previous experience with Redis, we’ll be staying with this solution for our back-end object cache.