BMAD-METHOD/docs/learn-wds/module-06-platform-architec.../tutorial-06.md

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Tutorial 06: Platform Architecture

Let Idunn translate your product vision into technical architecture - you speak design, she speaks code


Overview

You've designed the experience. Now you need the technical foundation to make it real. But you're a designer, not a developer - how do you define databases, APIs, and system architecture?

You don't. Idunn does.

You just describe your product in design language. Idunn translates it into Platform PRD.

Time: 30-45 minutes
Prerequisites: Module 05 completed (Trigger Map ready)
What you'll create: Platform PRD & Architecture Document


What You'll Learn

  • What a Platform PRD is (and why it matters)
  • How to describe your product's technical needs without being technical
  • How Idunn helps you think through platform decisions
  • What questions she'll ask (so you're not surprised)

What is Platform PRD?

Platform PRD = The technical blueprint developers need to build your product.

It includes:

  • System Architecture: How the pieces fit together
  • Data Models: What information needs to be stored
  • APIs & Integrations: How systems talk to each other
  • Technical Requirements: Performance, security, scalability

Your superpower: You don't need to know how to write this. You just need to know what your product does.


Step 1: Understand Your Role (2 min)

Your job as designer:

  • Describe what users need to do
  • Explain what data they create/view/edit
  • Identify third-party services you want (payments, auth, analytics)
  • Share any technical constraints you know about

Idunn's job:

  • Ask clarifying questions about technical needs
  • Translate your product into architecture decisions
  • Document data models, APIs, system diagrams
  • Flag technical risks and recommend solutions

You bring product knowledge. She brings technical expertise.


What to Expect: The Conversation

Here's how a real session with Idunn looks:

Idunn's Opening

Hi! I'm Idunn, your technical architect agent.

I see you've completed your Product Brief and Trigger Map. 
Let's translate your product vision into technical architecture.

I'll ask questions about your product in design language. 
You answer naturally - no need for technical terms.

Ready? Let's start with the basics.

Example Questions Idunn Asks

About Your Product:

Idunn: "What's the core thing users create or manage in your product?"

You: "Users create weekly schedules for family dog care - walks, 
      feeding, vet appointments, etc."

Idunn: "Got it. Do these schedules need to be:
        - Private (only one family)?
        - Shared (multiple families can see each other's)?
        - Collaborative (family members edit together)?"

You: "Collaborative - all family members edit the same schedule."

Idunn: "Perfect. That tells me we need real-time sync and user permissions."

About Users & Authentication:

Idunn: "How do you envision users signing up?"

You: "Email and password should work. Google login would be nice too."

Idunn: "Great! Should users be able to:
        - Invite family members?
        - Have different roles (admin vs. regular member)?"

You: "Yes! The person who creates the schedule is the admin. 
      They can invite family and remove members if needed."

Idunn: "Understood. I'll design a role-based permission system."

About Data & Features:

Idunn: "You mentioned tasks like 'walks' and 'feeding'. 
        What information does each task need?"

You: "Task title, who's assigned, what time/date, and whether 
      it's done or not."

Idunn: "Should tasks repeat? Like 'walk dog every morning'?"

You: "Oh yes! That would be super helpful."

Idunn: "I'll add recurring task patterns. Should we notify 
        the assigned person before the task is due?"

You: "Definitely!"

Idunn: "I'll include a notification system in the architecture."

Built-in Guidance from Idunn

When you're unsure:

You: "I'm not sure if we need that..."

Idunn: "No problem! Let me explain the trade-offs:

       WITH real-time sync:
       ✅ Family sees changes instantly
       ✅ No confusion about who's doing what
       ❌ Slightly more complex to build
       ❌ Requires internet connection

       WITHOUT real-time sync:
       ✅ Simpler to build
       ✅ Can work offline
       ❌ Family might have outdated info
       ❌ Conflicts if two people edit at once

       For family coordination, real-time is usually worth it.
       What feels right for your users?"

When technical terms come up:

Idunn: "I'll use a REST API for communication between app and server."

You: "What's a REST API?"

Idunn: "Think of it as a waiter in a restaurant:
        - Your app (customer) asks for something
        - The API (waiter) takes the request to the server (kitchen)
        - The server prepares the response (food)
        - The API brings it back to your app

        You don't need to know how it works - just that it's 
        the standard way apps communicate with databases."

When prioritizing features:

Idunn: "Based on your Product Brief, I see you want:
        - Task scheduling (core)
        - Notifications (important)
        - Calendar sync (nice-to-have)
        - Vet appointment reminders (nice-to-have)

        For the Platform PRD, I'll design all of these.
        
        But I'll flag which are 'MVP' (must-have) vs. 
        'Phase 2' (add later) so developers know priorities.
        
        Does that split make sense?"

You: "Yes, but actually calendar sync is really important."

Idunn: "Got it - moving calendar sync to MVP. I'll update the 
        architecture to prioritize that integration."

What Idunn Creates While You Talk

As you answer, Idunn is:

  • ✍️ Documenting data models ("Task" entity with fields)
  • 🏗️ Sketching system architecture (app, API, database, notifications)
  • 🔐 Planning authentication flow (login, permissions, roles)
  • 🔗 Identifying integrations (Google Calendar, email notifications)
  • ⚠️ Flagging technical risks ("Real-time sync needs WebSocket support")

You'll see progress updates:

Idunn: "✅ Data model drafted - 3 main entities (User, Family, Task)
        ✅ Authentication flow designed - Social login + email
        🔄 Working on notification system architecture..."

Step 2: Activate Idunn (2 min)

@idunn

I'm ready to create the Platform PRD for [Your Product Name].

I have:
- Product Brief (done)
- Trigger Map (done)

Please help me define the technical architecture.

Idunn will respond and start asking questions about your product's technical needs.


Step 3: Answer Idunn's Questions (20-30 min)

Idunn will guide you through understanding your platform needs. She asks questions like:

About Data

  • "What information do users create?"
  • "What needs to be saved vs. temporary?"
  • "Do users share data with each other?"

Example answers (you don't need technical terms):

  • "Users create weekly schedules for dog care tasks"
  • "Schedules need to be saved permanently and shared with family"
  • "Each task has: title, assigned person, date, completion status"

About Authentication

  • "How do users log in?"
  • "Do you want social login (Google, Apple)?"
  • "Are there different user roles?"

Example answers:

  • "Email + password, plus Google login"
  • "Two roles: Admin (can assign tasks) and Family Member (can complete tasks)"

About Integrations

  • "Do you need notifications?"
  • "Payment processing?"
  • "Calendar sync?"

Example answers:

  • "Yes! Send reminders before tasks are due"
  • "No payments needed"
  • "Would be nice to sync with phone calendar"

About Performance & Scale

  • "How many users do you expect?"
  • "Any real-time features?"
  • "Mobile app or web?"

Idunn translates this into:

  • Database schemas
  • API specifications
  • System architecture diagrams
  • Technical requirements docs

Step 4: Review & Refine (10 min)

Idunn will show you the Platform PRD. Don't panic if it looks technical - you don't need to understand every detail.

What to check:

  • Does it capture all the features you designed?
  • Are the user roles correct?
  • Did she understand your data needs?
  • Are integrations you wanted included?

Ask questions like:

  • "Can you explain this part in design terms?"
  • "How does this support [specific feature]?"
  • "What if we want to add [feature] later?"

Idunn will clarify and update the PRD until it's right.


Step 5: Save Your Platform PRD (2 min)

Idunn will save the Platform PRD to your project:

/docs/3-platform-prd/
├── 01-platform-architecture.md
├── 02-data-models.md
├── 03-api-specifications.md
└── 04-technical-constraints.md

You now have everything developers need to understand the technical foundation.


Common Questions

Q: Do I need to learn technical terms?
A: No. Speak in design/product language. Idunn translates.

Q: What if I don't know the answer to her questions?
A: Say so! Idunn will explain the implications and suggest options.

Q: Can developers change the architecture later?
A: Yes. This is a starting point. Developers may refine it.

Q: Do I need to review APIs and database schemas?
A: Only if you want to. Focus on whether it supports your design.


What You've Accomplished

🎉 You just created a Platform PRD - something that usually requires technical architects!

You didn't need to:

  • Learn database design
  • Understand API protocols
  • Draw system architecture diagrams
  • Write technical specifications

You just:

  • Described your product in design terms
  • Answered Idunn's questions
  • Reviewed to ensure it supports your design

That's the WDS superpower: You focus on design. The agents handle the technical translation.


Next Steps

Ready to design the UX?
Module 08: Initialize Scenario

Want to skip Platform PRD for now?
You can come back to this after UX design if you prefer.


Pro Tip: Even if you're not building the platform yourself, having this PRD helps you communicate with developers and make informed design decisions. You'll know what's technically feasible without becoming a developer yourself.