Hopefully if you're going to be making upstream requests on every page load (or every user login) the developer will be making sure to perform reasonable caching. Since this is Laravel it should be pretty configurable, but something to be conscientious of. Also, presumably the upstream service (e.g. growthbook, in this case) is utilizing standard HTTP cache headers that Guzzle can respect and cache centrally using the configured middleware (e.g. memcached if you're on a cluster or something).