Case Study

How a Fintech Engineering Team Cut Audit Prep from 3 Weeks to 2 Days

A walkthrough showing how VizRepo’s auto-generated documentation can serve as SOC 2 compliance evidence — without a single manually created diagram.

This is a representative walkthrough based on common audit scenarios in financial services. It illustrates how VizRepo’s features map to real compliance requirements.

The Problem

A Series A fintech startup — 12 engineers, 3 microservices, roughly 180 API endpoints — was approaching its first SOC 2 Type II audit. The auditor’s evidence request list included:

  • Data flow diagrams showing how PII is handled end-to-end
  • Documentation of every payment-related endpoint, including validation and error handling
  • Proof that documented data flows match the actual running codebase
  • Evidence that access control is implemented as described in security policies

What the team actually had: a handful of outdated Confluence pages, hand-drawn Lucidchart diagrams from six months ago, and no way to prove that current code matched current documentation. The diagrams showed an architecture that had already been refactored twice.

Their previous audit prep cycle had consumed three full weeks of engineering time — pulling developers off feature work to manually update diagrams, write endpoint descriptions, and cross-reference code with documentation. For a 12-person team, that was a significant cost.

The Approach

The team connected all three repositories to VizRepo: payment-service, user-service, and notification-service.

After the initial scan, VizRepo detected and generated:

  • 180 endpoints detected across all three services
  • 94 flowcharts and 86 sequence diagrams auto-generated from the code
  • 7-section AI documentation for each service — covering architecture overview, endpoint inventory, data models, authentication flows, error handling patterns, integration points, and deployment notes

The team enabled public documentation sharing so the auditor could access everything via a read-only link — no VizRepo account required. They also set up weekly scheduled scans to ensure documentation would stay current between audit cycles automatically.

What the Auditor Received

Instead of static screenshots and outdated wiki pages, the auditor received a live documentation link containing:

  • Payment endpoint flowcharts — for each endpoint (POST /payments/charge, POST /payments/refund, etc.), an auto-generated flowchart showing the exact code path including validation steps, error handling branches, and downstream service calls
  • Database schema ER diagrams showing how PII is stored and which services have access to which tables
  • User journey documentation — plain-English walkthroughs like “Customer makes a payment” with references to the specific endpoints and services involved at each step
  • Timestamps on every scan proving exactly when documentation was last generated — directly from the live codebase, not hand-drawn

The Result

Audit prep time
3 weeks2 days
Setting up VizRepo + reviewing output
Manual diagrams created
Zero
All diagrams generated from code
Quarterly review time
<1 hour
Re-run scan, share updated link

The auditor specifically called out the flowcharts as “the clearest data flow documentation we’ve seen from a company this size.”

Key Takeaway

Compliance documentation doesn’t have to be a project. If your docs are generated from your actual codebase, they’re always accurate, always current, and always audit-ready.

Ready to make your next audit effortless?