Requirements, Conceptual Design, and Technical Design: No-Fluff Guide

1. Requirements Gathering (Elicitation)

• Don't code before you know what to build.
• Ask probing questions, not just what's stated. (e.g., "No kitchen?" "Room sizes?" "External constraints?")
• Clarify ambiguities and missing info.
• House Example:
  • "Do you want a kitchen?"
  • "How big should the gym be?"
  • "Any building codes?"
• Software Example:
  • "What does 'search for courses' mean?"
  • "What filters?"
  • "What's a 'relevant' course?"

2. Conceptual Design

• Sketch the big pieces and their responsibilities, ignore implementation.
• Components = major parts (house: kitchen, gym; software: search page, course, input field).
• Connections = how components interact (living room connects to kitchen; search page connects to input field, results page).
• Responsibilities = what each part does (kitchen: meal prep; search page: search courses).
• Use mockups (hand-drawn or digital) to visualize.
• Don't specify tech details (no wiring, no database schema yet).

Example (Course Search):

graph TD
  A[Search Page] --> B[Input Field]
  A --> C[Search Button]
  A --> D[Results Page]
  D --> E[Course]

3. Technical Design

• Break down each component into smaller, implementable parts.
• Add technical details: how will each responsibility be fulfilled?
• House: Gym needs reinforced floor → design beams/columns.
• Software: Search page needs to query a course database → define API, data flow, error handling.
• Use technical diagrams (UML, flowcharts, etc.) to specify structure and behavior.
• Identify and resolve conflicts (e.g., gym floor reinforcement vs. open basement).

Example (Course Search, Technical):

// SearchPage.tsx
const handleSearch = async (keyword: string) => {
  const results = await fetch(`/api/courses?query=${encodeURIComponent(keyword)}`).then(res =>
    res.json()
  )
  setResults(results)
}

graph TD
  User -->|enters keyword| InputField
  InputField -->|triggers| SearchButton
  SearchButton -->|calls| APIServer
  APIServer -->|queries| CourseDatabase
  CourseDatabase -->|returns| APIServer
  APIServer -->|returns| ResultsPage

4. Iteration & Feedback

• Constantly check with stakeholders (client, users) to validate both conceptual and technical designs.
• Be ready to revise requirements and designs as new info or constraints emerge.

Actionable Takeaways

• Never skip requirements. Ask "what's missing?" and "what if?" questions.
• Draw conceptual mockups before any code or tech diagrams.
• Only after the conceptual design is clear, break it down into technical details.
• Use diagrams and sketches to communicate, not just text.
• Iterate: requirements ↔ conceptual design ↔ technical design, until all are solid.

Contrarian/Speculative

• For small projects, you can sometimes merge conceptual and technical design, but always do some requirements elicitation.
• For rapid prototyping, use "just enough" design, but document assumptions so you can refactor later.

Summary: You wanted a direct, code-level, and example-driven explanation of the importance and process of requirements gathering, conceptual design, and technical design, using both the house and course search website analogies, with actionable steps and no high-level fluff.