Security starts with a data map
List personal, payment and business-sensitive information; where it is stored; who may access it; and how long it is retained. Avoid collecting information that has no justified use.
App-side checks are not enough
Treat mobile devices and networks as potentially untrusted. Enforce authorization on the server and do not hide secrets inside distributed application packages.
Test what happens when things fail
Review login flows, expired sessions, unauthorized API requests, lost devices, invalid input, dependency vulnerabilities and backup exposure. Store listing and data disclosures must match actual behaviour.
No website or app is invulnerable
Risk reduction requires secure development, restricted hosting access, timely patches, monitoring and periodic reviews. Claims of being immune to all attacks would be misleading.