Design the API layer for developers to access AI models securely, keys, scopes, limits, and abuse controls.
A reported Anthropic system-design prompt. The skeleton is standard API platform work; the AI-specific 20%, token-denominated limits, safety classifiers in the path, abuse identity, is what the round actually grades.
Updated Aug 2026 · Grounded in real Forward Deployed Engineer interview loops and written to a senior-engineer editorial bar.
A reported Anthropic system-design prompt. The skeleton is standard API platform work; the AI-specific 20%, token-denominated limits, safety classifiers in the path, abuse identity, is what the round actually grades.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
