Customer Bootstrap API
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DoorDashFULLTIMEPHONE SCREENProblem statement
Implement a deterministic customer-bootstrap endpoint that orchestrates three downstream services.
First resolve an email address through USER to obtain a customer identifier. After that succeeds, resolve PAYMENT and ADDRESS independently; these two lookups are logically concurrent.
The input response schedule contains rows [service, attempt, latencyMs, statusCode, value]. The service is USER, PAYMENT, or ADDRESS. A missing row represents a timeout. For each service, inspect attempts from 1 through maxAttempts:
- A response succeeds when its latency is at most
timeoutMsand its status is 200. Return its value. - A response with latency greater than
timeoutMs, a missing response, or status 500 through 599 is retryable. - Any other status is terminal for that service.
If USER does not succeed, return three empty strings. Otherwise return [customerId, defaultCard, address]. A failed PAYMENT lookup contributes UNKNOWN_CARD; a failed ADDRESS lookup contributes UNKNOWN_ADDRESS. The independent downstream lookup may succeed even when the other one fails.
Function
bootstrapCustomer(email: String, timeoutMs: int, maxAttempts: int, responses: String[][]) → String[]Examples
Example 1
email = "alex@example.com"timeoutMs = 100maxAttempts = 2responses = [["USER","1","20","200","c42"],["PAYMENT","1","150","200","card-old"],["PAYMENT","2","40","200","card-7"],["ADDRESS","1","30","503",""],["ADDRESS","2","25","200","12 Main St"]]return = ["c42","card-7","12 Main St"]The user lookup succeeds immediately. The first payment response exceeds the timeout and the first address response is retryable, so both downstream services succeed on attempt 2.
Constraints
1 <= email.length <= 2541 <= timeoutMs <= 600001 <= maxAttempts <= 100 <= responses.length <= 30- Every row has exactly five fields and names one of the three services.
- Each service has at most one row for a given attempt number; attempt numbers are in
[1, maxAttempts]. - Latency and status fields are decimal integers. Latency is nonnegative.
- Values contain at most 200 visible ASCII characters.