Top 3 Charging Interview Questions
Browse 3 real-world technical and behavioral interview questions about Charging. Review scenarios, edge cases, and architectural best practices.
Usage records arrive duplicated, late and out of order, and the tariff changed in the middle of the month. How does mediation and rating cope?
Mediation normalises and deduplicates records against a persisted key window sized to the worst observed lateness, then rating prices each record by its event time against an effective-dated tariff version. Prepaid is not merely faster postpaid; it reserves quota against a live balance.
A family plan shares 100 GB across five SIMs with each SIM capped at 30 GB. How does charging enforce both limits at once?
Every reservation must decrement the shared pool and the member's own counter atomically, granting the smallest of the two remainders. That makes the group rather than the subscriber the serialisation point, and it means a member with headroom can still be refused because the pool is gone.
A subscriber goes abroad and their roaming charges only reach you days later. How does charging cope with that?
Roaming splits usage from its record: the visited operator meters it and sends files later, so postpaid rates on records that may miss the bill and prepaid cannot wait at all. The design turns on which usage you allow before you have proof of it, and what the delay costs when it is fraud.