Verifying realistic network conditions.
WHY IT MATTERS HERE
Most users are on mobile data, with variable quality.
WHAT TO SIMULATE
High latency Low bandwidth Packet loss Intermittent disconnection Connectivity lost mid-request
WHAT TOOLS PROVIDE
Throttling and condition simulation, in browsers and on devices.
WHAT TO TEST
Whether loading indicators appear Whether timeouts are sensible Whether failures are explained Whether retry is offered Whether partial data is handled
WHAT TO VERIFY ABOUT INTERRUPTED REQUESTS
That the outcome is determined rather than assumed.
WHY THAT MATTERS MOST
A request that succeeded but appeared to fail causes duplicates.
WHAT TO TEST ABOUT RESUMPTION
Returning after being offline.
WHAT TO VERIFY
That queued actions are sent That they are not duplicated That state is reconciled
WHAT TO TEST ABOUT LARGE TRANSFERS
Uploads and downloads failing partway.
WHAT TO MEASURE
Time to usable, on a throttled connection.
WHY
It is what your users actually experience.
WHAT TO TEST ON
A modest device, on mobile data, at a busy time.