# Design a loan origination system: system design interview question

> Applications that span days: external checks, valid approvals, recovery after failures, and one disbursement per loan.

Source: https://sysround.com/questions/design-loan-origination-system
Updated: 2026-11-05


Difficulty: hard. Levels: Senior, Staff+.

## How the interviewer opens it

"Design a loan origination platform that manages applications through verification, underwriting, approval, and disbursement. The platform must coordinate external providers and long waits without disbursing a loan twice."

## What to clarify first

- Loan product
- Scale
- Read and write mix
- Checks and duration
- Latency
- Consistency and availability
- External providers
- Durability and history
- Application changes and decisions
- Deployment and exclusions

## Scope of a strong answer

Core requirements:

- Accept applications and track their progress
- Coordinate external checks and manual review
- Approve or reject applications under supplied rules
- Disburse each approved loan without duplicate transfers

Usually out of scope:

- Repayment and collections
- Credit model development
- The bank's transfer system
- Partial disbursements and multiple currencies

## What interviewers probe

### Application progress

Applications wait for days while workers fail and providers repeat results. The platform must resume work without losing progress.

### Approval validity

Applicants and reviewers can change the same application while checks remain active. A valid approval must refer to the exact facts that authorize payment.

### Disbursement outcomes

The database and bank cannot share one transaction. A timeout leaves an unknown outcome, and a new transfer attempt can pay twice.

## Common mistakes

- Keeps a database transaction open during an external call
- Assumes a timeout proves that no transfer occurred
- Uses retries without stable request identities
- Ignores application changes while checks and reviews remain active
- Treats workflow state as a complete financial or decision history
- Adds many services despite modest throughput and closely related state

## The bar by level

- **Senior:** Makes workflow recovery concrete. Preserves acknowledged changes across an availability zone failure. Handles duplicate callbacks, stale decisions, and concurrent payouts. Uses transactions and bank deduplication.
- **Staff+:** Defines guarantees across the bank boundary. Handles contract limits, operator recovery, policy changes, and regional failure. Connects audit evidence and security controls to business invariants.

Practice this question with an AI interviewer: https://sysround.com/practice/new?problem=loan-origination


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SysRound (https://sysround.com) is an AI practice tool for system design interviews. It has a voice or typed AI interviewer and a shared whiteboard. At the end, you get feedback on each skill and a model answer. The AI feedback can be wrong.