New Relic Interview Question

The Home work: Using any of the following programming language (taking performance into consideration): Java, Kotlin, Python, Go, write a server ("Application") that opens a socket and restricts input to at most 5 concurrent clients. Clients will connect to the Application and write one or more numbers of 9 digit numbers, each number followed by a server-native newline sequence, and then close the connection. The Application must write a de- duplicated list of these numbers to a log file in no particular order.