Design PII-safe call summarisation for an Indian contact centre

Suraksha Life (fictional), a life insurer, runs a contact centre in Noida and Chennai. Agents currently spend about 90 seconds after each call typing notes into the CRM, and the notes are often incomplete.

The client wants every call summarised automatically into structured CRM fields: reason for call, policy number, actions promised, follow-up date, complaint flag, and a 3-line summary.

Constraints:

• 85,000 calls a day, average 5.5 minutes, peak 9,000 calls an hour. Languages: Hindi, English, Tamil, Marathi, frequently mixed within one sentence.
• Summary must appear in the CRM within 2 minutes of call end.
• Customers sometimes read out card numbers and CVVs during premium payments. These must never be stored in transcripts, logs or summaries (PCI DSS). Aadhaar and PAN numbers also come up.
• Personal data must stay in India under the client's reading of the DPDP Act and their regulator's outsourcing guidelines. Call recordings already sit in an India-region object store.
• All-in budget: ₹2.50 per call, including speech-to-text.
• The complaint flag feeds a regulatory complaints register; missing a complaint is far worse than a false flag.
• The CRM accepts updates through a REST API with a fixed JSON schema.

Design the system.