Solutions / Use Case
Loan Application Processing with Decision Engine and Human Review
Loan approval pipelines are long-running and policy-heavy. This page shows a practical pattern for implementing them with Switch Steps, Decision Engine rules, Human-in-the-Loop wait states, and loopback handling for additional information requests.
Input Validation and Early Exit
Loan requests typically begin with basic applicant data. Instead of writing custom validation handlers across services, you can gate the process with a Switch Step at the workflow entry.
- Run input checks at the entry point using a Switch Step.
- Exit incomplete or invalid applications immediately.
- Avoid spending compute and downstream service calls on dead requests.
Input Validation Path
Handle User Submit
# loan.request.create
Validate Inputs
# Switch
Continue Process
# next_step
Exit
# stop
Risk and Credit Evaluation
After the initial gate, data collection is a good place to use parallel execution. Instead of calling credit, risk, and history services one-by-one, fetch them in parallel and join the results into a single normalized object for the next decision step.
This pattern cuts end-to-end latency and keeps the flow easier to reason about: one fan-out, one join point, one script step to shape inputs for downstream rules.
Parallel Data Fetch
Fetch Data
# fetch_data
Get Credit Score
# credit_score
Get Risk Profile
# risk_profile
Get User History
# user_history
Organize Inputs
# organize_inputs
Decision Engine as the Core of the Workflow
Business policy changes are frequent in lending. If criteria is embedded in backend code, every policy update becomes a code change and redeploy cycle. Decision tables keep this policy layer explicit and easier to evolve.
- Keep approval criteria in decision tables rather than hard-coded backend branches.
- Update policy behavior without refactoring orchestration code paths.
- Maintain explicit rule logic that can be reviewed and audited over time.
Decision Routing
Decide Approval
# decide_approval
Route
# Switch
Analyst Approval
Manager Approval
Auto Approval
Reject
Human in the Loop for Secure Approvals
High-risk cases need human oversight. The operational challenge is not the decision itself; it is maintaining long-running workflow state while waiting.
- Pause safely at manager review points without custom timer/poller infrastructure.
- Resume from the same workflow state when a human decision arrives.
- Support long-running approvals without keeping application compute busy.
Handling Additional Information Requests
Real-world loan reviews often request more data. Workflow loopback should be first-class rather than implemented as ad hoc restart logic.
- If additional information is required, route back for updates without restarting the whole process.
- Re-enter the same decision path after new data is submitted.
- Keep full history of what changed and why each branch was taken.
Additional Info Routing
Route
# switch
Finalize Application
# finalize_application
Final Outcome: Approval or Exit
Approved applications proceed to disbursement. Rejected applications exit cleanly. Every execution path remains traceable with the exact workflow version that ran at that time, which is important for audits and policy evolution.
Ready to build this loan workflow?
Start with one flow map from intake to disbursement, then extend rules and human-review levels without rewriting core application code.