The perfect metaphor for web architecture doesn't exi--
Backend: Three people cooking in primitive conditions with giant pots over open flames. The unsung heroes doing the actual heavy lifting while covered in sweat and smoke.
Frontend: A polished restaurant interior with mood lighting and fancy tables. Looks great but completely useless without the backend's cooking.
APIs: The waitstaff in formal attire carrying food from kitchen to table. They don't make anything themselves but get all the tips for simply transferring data between systems.
And somehow management still wonders why backend developers are always grumpy.