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Design a loan application system

ParafinSoftware Engineer · Onsite
HardSoftware EngineerOnsiteSystem Design

Last updated

Design a loan application system evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

Design an end-to-end loan application system for a small online lending platform. Users choose among different loan products and submit applications; the system performs internal review/underwriting and integrates with third‑party providers to fetch credit history and bank‑account transaction data. Describe: (

  1. the high‑level architecture (service boundaries, data models, APIs, queues/workflows/state machine); (
  2. the approval/denial path and post‑decision actions, including funds disbursement/transfer; and (
  3. operational concerns: idempotency, retries, timeouts, rate limiting, and handling partial failures when calling external APIs. Explain how you will implement KYC/AML and fraud checks, protect PII and meet compliance/audit needs, support manual review tooling, and ensure observability, scalability, and backpressure under growth. Compare synchronous vs asynchronous processing and justify trade‑offs.