Project Planning - PRDs and Requirements

development project-planning prd requirements


Why Planning Matters

Even for solo projects, writing down what you’re building before you build it prevents scope creep, wasted effort, and the classic “I’ll just figure it out as I go” spiral. A lightweight planning document forces you to think through the problem, define what success looks like, and set boundaries on what’s in and out of scope.

The bigger the project, the more this pays off — but even a 30-minute planning session for a weekend project saves hours of rework.


Common Planning Documents

DocumentPurposeWhen to Use
PRD (Product Requirements Document)Defines what to build and why — the problem, goals, users, and success criteriaStarting a new product or major feature
RFC (Request for Comments)Proposes a technical approach and invites feedback before committingArchitectural decisions, new patterns, breaking changes
Design Doc / Technical SpecDetails how to build it — system design, data models, API contractsComplex features requiring upfront architecture
User StoriesCaptures requirements from the user’s perspectiveBreaking features into implementable chunks
Acceptance CriteriaDefines when a story or feature is “done”Attached to each user story or task

How They Relate

Idea / Problem
    │
    ▼
  PRD  ──────────  "What are we building and why?"
    │
    ▼
  RFC / Design Doc  "How should we build it?"
    │
    ▼
  User Stories  ───  "What does the user need to do?"
    │
    ▼
  Acceptance Criteria  "How do we know it's done?"

Anatomy of a PRD

A PRD doesn’t need to be a 20-page corporate document. At its core, it answers these questions:

SectionWhat It Covers
Problem StatementWhat problem are we solving? Who has this problem?
GoalsWhat does success look like? (measurable if possible)
Non-GoalsWhat are we explicitly not doing? (prevents scope creep)
User StoriesKey user workflows this feature enables
RequirementsFunctional (what it does) and non-functional (performance, security)
Success MetricsHow we’ll measure if this worked
Scope & TimelineWhat’s in v1 vs. later, rough milestones
Open QuestionsUnresolved decisions that need answers

Example: Minimal PRD Template

# PRD: [Feature/Project Name]
 
## Problem
[1-3 sentences describing the problem]
 
## Goals
- [Goal 1]
- [Goal 2]
 
## Non-Goals
- [What we're NOT doing]
 
## User Stories
- As a [user type], I want [action] so that [benefit]
 
## Requirements
### Must Have
- [Requirement]
 
### Nice to Have
- [Requirement]
 
## Success Metrics
- [How we measure success]
 
## Open Questions
- [Unresolved decisions]

Writing Effective User Stories

User stories follow a simple format:

As a [type of user], I want [goal/action], so that [reason/benefit].

Examples

StoryWhy It Works
As a new user, I want to sign up with my email so that I can access the platformClear actor, action, and motivation
As an admin, I want to export logs to CSV so that I can audit activity offlineSpecific and testable
As a developer, I want CLI output in JSON format so that I can pipe it to other toolsTechnical but user-focused

Tips

  • Keep stories small enough to complete in one sprint (1-2 weeks)
  • Each story should be independently valuable — not just “part 1 of 5”
  • Attach acceptance criteria to each story: specific conditions that must be true for it to be considered done

Acceptance Criteria Example

Story: As a user, I want to reset my password via email.

Acceptance Criteria:

  • User receives reset email within 60 seconds
  • Reset link expires after 24 hours
  • Password must meet complexity requirements
  • User is logged in automatically after reset

Discovery Process

The typical flow from idea to implementation:

1. IDENTIFY     Spot a problem or opportunity
       │
2. RESEARCH     Understand users, constraints, existing solutions
       │
3. DEFINE       Write the PRD — scope, goals, non-goals
       │
4. DESIGN       Technical spec / RFC — how to build it
       │
5. VALIDATE     Review with stakeholders, poke holes
       │
6. BUILD        Break into stories, start sprints
       │
7. MEASURE      Check against success metrics, iterate

Key principle: Steps 1-5 are cheap. Building the wrong thing is expensive. Invest time in discovery to build the right thing.


Applying to Solo / LLM Projects

You don’t need a full corporate PRD process for personal projects, but a lightweight version pays off significantly — especially when working with LLMs.

Why It Matters Even More with LLMs

  • LLMs work better with clear context. A PRD gives the AI the same “big picture” you have in your head.
  • Scope control. Without written boundaries, it’s easy to let the AI keep adding features you never planned for.
  • Session continuity. When you start a new chat, you can paste the PRD and the AI picks up where you left off.

Lightweight Solo Workflow

  1. Write a mini-PRD (even just the problem, goals, and non-goals — 10 minutes)
  2. Iterate with the LLM — ask it to poke holes in your requirements before writing code
  3. Break into user stories — use them as individual prompts/tasks
  4. Keep a living doc — update the PRD as the project evolves

Template: Solo Project PRD

# Project: [Name]
 
## Problem
[What am I solving?]
 
## Goals (v1)
- [Keep it to 3-5 goals max]
 
## Non-Goals
- [What I'm NOT building yet]
 
## Key Features
- [ ] Feature 1
- [ ] Feature 2
 
## Tech Stack
- [Language, framework, key tools]
 
## Open Questions
- [Decisions I haven't made yet]

Put this in your project repo (as PRD.md or in a docs/ folder) and reference it at the start of LLM sessions.