This content originally appeared on DEV Community and was authored by Aaron K Saunders
In this video, I show my real workflow for turning a rough idea into clear, client-ready documentation—using AI.
I take a simple church visitor intake example (QR code → form → database → emails/postcards) and use T3Chat (GPT-5 Reasoning) to generate:
- A high-level Product Requirements Document (PRD)
- An Entity Relationship Diagram (ERD) with Mermaid syntax
- Database tables and fields you can drop into a spreadsheet
- Flow and swimlane diagrams you can paste into Mermaid Live Editor This approach helps with client discovery, statements of work (SOW), estimates, and aligning technical and non-technical stakeholders—without needing super-detailed prompts.
The Video
What you’ll learn:
- The exact prompt structure I use to get PRD, ERD, tables, and diagrams
- How to paste Mermaid output into Mermaid Live Editor for instant visuals
- How to validate requirements with teams/clients using generated docs
- Tips for exporting tables to spreadsheets for easier reviews
In the context of system design, a swimlane diagram is a powerful tool for visualizing the interactions and responsibilities between different components within a system element like microservices, APIs, databases and external system.
Resources mentioned:
- Full document output
- Mermaid Live Editor: https://mermaid.live
- Alternative AI tools to try: ChatGPT, Gemini, Claude
If you want the exact prompt I used, grab it in the link above. Drop your questions and share what AI tools you’re using for requirements and docs—I’ll feature some in a future video.
The Prompt
i need to create a solution for mu church group to capture information from guests and have a way for them to scan a QR code that launches a web app for them to enter information for us to add them to a system. the system needs the ability to export the list so i can then create welcome post cards to send to them. if they provided and email address that we could send an email if they opted in.
create a product requirement document, create an ERD, create a table with field name, and appropriate description for the tables in the database, create a flow diagram to display application flow, create a swim diagram to show flow from technical perspective
The Diagram
This content originally appeared on DEV Community and was authored by Aaron K Saunders