Each VIP Go site is provisioned with its own siloed Memcache cluster for caching application level data, and the WordPress object cache (and transients) are automatically configured to use these instances. This means that many common operations will automatically be routed to memory instead of the database.
This also means that any application data can be easily cached in memory, to reduce the cost of repetitive or expensive computations. The best candidates for caching are any data that will take longer to calculate (such as expensive database queries) than it takes to grab the data from the cache, keeping in mind each cache request is processed over the local network, so a very large number of cache lookups/sets can add processing time to the page. Cache entries must be kept under 1MB in size.
For more information on using object caching in WordPress, see WP Object Cache.