> ## Documentation Index
> Fetch the complete documentation index at: https://docs.drpn.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Engineering process

> How Darpan changes are traced, implemented, verified, and documented.

Darpan engineering work starts from product behavior and follows it through the real routes, services, entities, tests, logs, and documentation. The areas below are the checkpoints that keep a single workflow change traceable end to end.

## Work areas

| Area                   | Contribution                                                                                                  |
| ---------------------- | ------------------------------------------------------------------------------------------------------------- |
| Codebase discovery     | Traces a product behavior from app route to API client, facade service, entity, backend helper, and test.     |
| UI implementation      | Keeps custom UI in the Vue app while reusing shared page and workflow patterns.                               |
| Backend implementation | Keeps service contracts explicit in Moqui XML and places dense processing in testable Groovy or Java helpers. |
| Reconciliation logic   | Preserves the split between Spark dataset work and Drools-backed decisioning.                                 |
| Verification           | Runs focused checks, reports what passed, and calls out remaining risk.                                       |
| Documentation          | Updates product and engineering docs from implemented behavior instead of planned architecture.               |

## Engineering principles

Darpan changes preserve repository ownership boundaries, keep backend behavior contract-first and Moqui-native, and use tests, logs, and runtime behavior as evidence.

## Why it matters for Darpan

A single visible workflow can touch saved setup, schema selection, source data, tenant access, JSON-RPC services, Spark comparison, Drools rules, generated output, and result review. Good engineering keeps that chain visible and verifies the specific link it changes.