Controlling consumption.
WHAT DRIVES COST
Document reads, writes and deletes Function invocations and duration Storage and bandwidth Phone authentication messages
WHAT MAKES IT DIFFERENT FROM SERVER-SIDE PLATFORMS
Clients generate cost directly, so a defect in an application multiplies across every installation.
WHAT THAT LOOKS LIKE
A listener attached repeatedly, generating continuous reads A screen reading a whole collection A function loop
WHAT TO SET IMMEDIATELY
Budget alerts.
WHY ALERTS RATHER THAN CAPS
Most services do not stop at a limit, so alerting is your warning.
WHAT TO DESIGN FOR
Few reads per screen Pagination on every list Caching locally Listeners attached and detached correctly
WHY THAT LAST POINT
A listener not removed continues consuming reads.
WHAT TO MONITOR
Reads per active user Function invocation counts Any sudden change
WHAT TO TEST
Cost implications, with realistic usage, before release.
WHAT TO REVIEW AFTER EVERY RELEASE
Consumption, for a sudden rise.
WHAT TO PREPARE
The ability to disable a feature remotely.
