Rate Limiting for APIs | Dataford Interview Questions

Implement a basic rate-limiter that restricts Snap API requests based on user ID and IP address.

Process requests in chronological order using a fixed-size sliding window. A request is allowed only when both its user ID and IP address have made fewer than limit allowed requests during the previous window seconds.

The function receives requests as [timestamp, user_id, ip_address] records and returns a Boolean for each request. Rejected requests do not count toward future limits.

Constraints

0 <= requests.length <= 1000
Each request has the form [timestamp, user_id, ip_address]
Requests are sorted by nondecreasing timestamp
0 <= timestamp <= 10^9
1 <= limit <= 10^5
1 <= window <= 10^9
user_id and ip_address are non-empty strings
Rejected requests do not count toward either limit

Function Signature

def rate_limit(requests, limit, window):

Your question is Rate Limiting for APIs. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Implement a basic rate-limiter that restricts Snap API requests based on user ID and IP address.

The function receives requests as [timestamp, user_id, ip_address] records and returns a Boolean for each request. Rejected requests do not count toward future limits.

Constraints

0 <= requests.length <= 1000
Each request has the form [timestamp, user_id, ip_address]
Requests are sorted by nondecreasing timestamp
0 <= timestamp <= 10^9
1 <= limit <= 10^5
1 <= window <= 10^9
user_id and ip_address are non-empty strings
Rejected requests do not count toward either limit

Function Signature

def rate_limit(requests, limit, window):

Your question is Rate Limiting for APIs. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.