Here’s a question: when was the last time you wrote down requirements before you started coding?
If you’re like most developers, the answer is “never” or “only when forced to by corporate process.” Requirements feel like busywork. They’re long, boring documents that get outdated the moment development starts. So we skip them and jump straight into code.
Then, three weeks later, someone asks: “Wait, are we supporting OAuth and email/password auth, or just one?” And you realize nobody actually decided. You were building based on vibes.
Here’s the truth: requirements don’t fail because they’re a bad idea—they fail because they’re written wrong. Traditional requirements documents are too detailed, take too long to write, and get ignored the moment the project shifts. What you need instead is a Technical Requirements Document (TRD): lightweight, specific, and actually used.
And here’s the best part: you can generate one in 20 minutes using ChatGPT.
What Is a TRD (And Why It Matters)
A Technical Requirements Document is a structured outline of what you’re building, who it’s for, and what success looks like. It’s not a 50-page waterfall spec with UML diagrams. It’s a clear, scannable document that answers these questions:
- What problem are we solving? (The “why”)
- Who is this for? (Users, stakeholders, personas)
- What are we building? (Core features and scope)
- What are we NOT building? (Explicit non-goals to prevent scope creep)
- Technical constraints? (Platform, performance, compliance, integrations)
- Success criteria? (Measurable outcomes, acceptance thresholds)
That’s it. No fluff, no filler. Just enough structure to keep everyone aligned without drowning in bureaucracy.
Why TRD-First Beats “Just Start Coding”
Prevents Scope Creep: When someone says “we should also add…” you check the TRD. If it’s not there, it’s a new project—not this one.
Aligns Teams: Product, design, and engineering read the same document. No more “I thought we were building X” surprises three weeks in.
Traces Decisions: Every backlog item references the TRD. Every feature maps to a requirement. When someone asks “why did we build this?” you point to section 3.2.
Speeds Up Onboarding: New team members read the TRD and understand the project in 15 minutes instead of osmosing context over three weeks.
Makes Planning Executable: You don’t plan by guessing. You extract work from requirements. Canvas → Plan → Backlog all derive from the TRD.
How to Generate a TRD Using ChatGPT
You don’t need to be a requirements engineer. You just need 20 minutes and a good ChatGPT prompt.
Step 1: Gather Context (5 minutes)
Before you talk to ChatGPT, jot down:
- The problem you’re solving (1-2 sentences)
- Who it’s for (users, customers, internal teams)
- Key features (bullet list, rough ideas)
- Constraints (tech stack, platform, timeline, compliance)
Example: “We need a real-time notification system for our SaaS app. Users should get instant alerts for mentions, comments, and critical events. Must be GDPR-compliant, work on web and mobile, and handle 10k concurrent users. We’re using Node.js + Postgres.”
Step 2: Use This ChatGPT Prompt (2 minutes)
You are a technical requirements specialist. Generate a Technical Requirements Document (TRD) based on the following project:
Problem: [Describe the problem]
Target Users: [Who is this for?]
Key Features: [Bullet list of core functionality]
Constraints: [Technical, regulatory, or business constraints]
The TRD should include:
1. Executive summary (2-3 sentences)
2. Problem statement
3. Target users and personas
4. Core functional requirements (numbered list)
5. Non-functional requirements (performance, security, compliance)
6. Explicit non-goals (what we're NOT building)
7. Success criteria (measurable outcomes)
8. Technical constraints and dependencies
9. Risks and assumptions
Format as markdown. Be specific but concise. Use SMART criteria for success metrics.
Paste your context into the prompt and hit enter.
Step 3: Refine the Output (10 minutes)
ChatGPT will generate a structured TRD. Now you refine it:
- Add specifics: Turn “must be fast” into “page load under 200ms”
- Trim fluff: Remove obvious statements like “system must be stable”
- Clarify non-goals: Explicitly state what you’re NOT doing (this prevents scope creep)
- Add technical details: If ChatGPT said “use a database,” specify Postgres + JSONB columns for flexible schema
Step 4: Review with Your Team (3 minutes)
Share the TRD in Slack/email. Ask:
- “Did we miss anything critical?”
- “Are the success criteria measurable?”
- “Do the non-goals make sense?”
Incorporate feedback. Now you have a shared source of truth that everyone approved.
A Real Example: User Authentication System
Let’s walk through a real TRD for a user authentication feature.
Prompt Input
Problem: Our app currently has no user authentication. Users can't save preferences, we can't personalize experiences, and we have no access control.
Target Users: SaaS customers (B2B) and internal admin users
Key Features:
- Email/password signup and login
- OAuth (Google, Microsoft)
- Role-based access control (admin, user, guest)
- Password reset via email
- Session management with JWT tokens
Constraints:
- Must be GDPR-compliant (EU users)
- Must integrate with existing Node.js/Express backend
- Must support 10k concurrent sessions
- Timeline: 3 weeks
ChatGPT Output (Condensed)
# TRD: User Authentication System
## 1. Executive Summary
Build a secure authentication system supporting email/password and OAuth (Google, Microsoft) with role-based access control. Must handle 10k concurrent sessions and comply with GDPR.
## 2. Problem Statement
The app lacks user authentication, preventing personalization, preference storage, and access control. This blocks key product features and creates security/compliance risks.
## 3. Target Users
- **Primary:** B2B SaaS customers (team members, admins)
- **Secondary:** Internal admin users managing customer accounts
## 4. Functional Requirements
4.1 Users can sign up via email/password with validation (email format, password strength)
4.2 Users can log in with email/password or OAuth (Google, Microsoft)
4.3 System assigns roles (admin, user, guest) with distinct permissions
4.4 Users can reset passwords via secure email challenge
4.5 Sessions managed via JWT tokens (expiry: 24 hours, refresh tokens: 30 days)
## 5. Non-Functional Requirements
5.1 **Security:** Passwords hashed with bcrypt (cost factor 12), tokens signed with RS256
5.2 **Performance:** Authentication requests complete in <300ms (p95)
5.3 **Scalability:** Support 10k concurrent sessions
5.4 **Compliance:** GDPR-compliant (consent, data portability, right to deletion)
## 6. Non-Goals (What We're NOT Building)
- Multi-factor authentication (2FA)—planned for Phase 2
- Social login beyond Google/Microsoft
- Single Sign-On (SSO) for enterprise—separate project
- Passwordless magic links
## 7. Success Criteria
- 95% of signup flows complete without errors
- OAuth login success rate >98%
- Zero unauthorized access incidents in first 30 days
- Pass GDPR audit checklist
## 8. Technical Constraints
- Node.js 18+ / Express backend
- Postgres 14+ for user storage
- Redis for session caching
- Must integrate with existing API routes (/api/v1/*)
## 9. Risks & Assumptions
- **Risk:** OAuth provider downtime affects login (Mitigation: Email/password fallback)
- **Assumption:** Users will accept 24-hour session expiry
- **Assumption:** Email delivery (password reset) succeeds within 2 minutes
How the TRD Flows Into Your Workflow
Once you have a TRD, everything else becomes mechanical:
TRD → Canvas
- Vision: “Build secure, GDPR-compliant auth that scales to 10k users”
- Goals: “95% signup success rate, <300ms auth latency”
- Stakeholders: “B2B customers, internal admins, security team”
- Questions: “Do users prefer OAuth or email/password?” (Add user research task)
TRD → Plan (Now/Next/Later)
- Now:
- Email/password signup (TRD 4.1)
- JWT token management (TRD 4.5)
- Next:
- OAuth integration (TRD 4.2)
- Password reset flow (TRD 4.4)
- Later:
- 2FA (explicitly in non-goals, Phase 2)
TRD → Backlog
Each requirement becomes a backlog item:
## AUTH-001: Email/Password Signup
- TRD Ref: Section 4.1
- Priority: High
- Effort: 3 days
- Acceptance Criteria:
- Email validation (RFC 5322 format)
- Password strength: min 12 chars, 1 uppercase, 1 number, 1 symbol
- bcrypt hashing (cost 12)
- Return JWT token on successful signup
- Error handling for duplicate emails
Every backlog item traces back to the TRD. No orphan features. No “we thought it’d be cool to add…” surprises.
Common Mistakes (And How to Avoid Them)
Mistake 1: Being Too Vague
Bad: “System must be fast” Good: “Authentication requests complete in <300ms at p95”
Always use specific, measurable criteria.
Mistake 2: Skipping Non-Goals
If you don’t explicitly say what you’re NOT building, people will assume it’s in scope. Write it down: “No 2FA in Phase 1. No magic links. No SSO.”
Mistake 3: Writing Once and Forgetting
Requirements evolve. When scope changes, update the TRD. When you add a large feature, reference it in the TRD. Keep it alive.
Mistake 4: Making It Too Long
If your TRD is over 5 pages, you’ve written a spec, not a requirements doc. Compress. Use bullet points. Link to external docs for details.
Why This Works
Traditional requirements fail because they’re disconnected from execution. You write a doc, file it away, and never look at it again. The TRD is different because it’s the source of truth that feeds everything else.
- Canvas derives vision from TRD
- Plan extracts features from TRD
- Backlog items reference TRD sections
- ADRs cite TRD constraints (“We chose Postgres per TRD 8.1”)
It’s not documentation for compliance—it’s the foundation of your workflow.
Try It Yourself
Pick a feature you’re about to build. Spend 20 minutes generating a TRD using the ChatGPT prompt above. Then:
- Share it with one teammate and ask: “Does this match your understanding?”
- Write one backlog item that references the TRD
- When someone suggests a new feature, check: “Is this in the TRD?”
That’s it. You’ll immediately see the difference between planning by vibes and planning with requirements.
Coming in Post 3: Canvas Thinking: Align Before You Build — Learn how six lightweight files prevent teams from building different visions of the same product, and why context alignment matters more than code quality.
Keywords: technical requirements document, TRD, requirements engineering, ChatGPT for planning, AI-assisted requirements, software project planning