Do you know about TDD?
Wait, I’m not talking about Test-Driven Development (the one where you write tests before writing code). I mean Technical Design Documents.
You’ve probably heard of them in passing or maybe even written one. But do you really know how important they are? Let’s dive into what TDDs are, why they’re essential, and how they can save you hours of frustration (and debugging).
What Even is a Technical Design Document?
Think of a Technical Design Document (TDD) as the blueprint of your project.
It’s a detailed, written description of:
- What you’re building.
- Why you’re building it.
- How you’re going to build it.
Sounds boring? Maybe. But trust me it’s far from unnecessary.
A TDD gives your team a single source of truth
It’s like having a map before you start a road trip
- Everyone knows the destination.
- Everyone knows the route.
- Fewer detours, fewer fights, and no one asks, “Are we there yet?”
Why You Need a TDD (Even if You Think You Don’t)
Let me guess, you’re thinking:
Why waste time writing a TDD when I can just start coding? Here’s the thing: skipping a TDD is like jumping into a pool without checking if there’s water. Sure, you might be fine, but there’s a good chance you’ll regret it.
Here’s What Happens Without a TDD:
- Miscommunication: Your team isn’t aligned.
- Unnecessary work: You end up building things nobody asked for.
- Scope creep: The project grows into a monster you can’t tame.
And What Happens With a TDD?
- Everyone knows what’s being built.
- You avoid rework and save time.
- The project stays on track (and your sanity stays intact).
So, the question isn’t, “Why write a TDD?” it’s Why wouldn’t you?
When Do You Write a TDD?
The best time to write a TDD? Right at the start of the project.
Here’s what it focuses on:
- System design: What’s the architecture going to look like?
- Purpose: Why are we building this, and who benefits?
- Documentation: How can this guide the team through development?
Starting with a TDD feels like extra work upfront, but it pays off massively when your team has clear goals and direction.
5 Reasons Why TDD is a Game-Changer
Still not convinced? Let me hit you with five reasons why TDDs are worth the effort:
- Clarity: Forces you to deeply think through the solution.
- Communication: Keeps everyone on the same page.
- Focus: Helps prevent unnecessary features from creeping in.
- Quality: Encourages better planning, leading to better code.
- Time-saving: Reduces back-and-forth, rework, and debugging.
How to Write a TDD Example (Without Overthinking It):
A TDD doesn’t have to be complicated. Here’s a quick checklist to get you started:
✅ System Overview: What’s the high-level idea?
✅ Functional Requirements: What must the system do?
✅ Non-Functional Requirements: How should it perform (speed, scalability, etc.)?
✅ Architecture Diagram: A simple visual map of the system.
✅ Tech Stack: What tools and frameworks are we using?
✅ Testing Plan: How do we ensure everything works as expected?
You don’t need to write a novel; just make sure it’s clear enough for the team to understand and use.
Why Skipping TDD Feels Good (But Isn’t Worth It)
Skipping a TDD can feel great in the moment. You get to dive straight into coding no boring documentation, no wasted time, just raw problem-solving, right?
Wrong.
Here’s the reality:
- No TDD = confusion, delays, and frustration.
- No roadmap = wandering aimlessly.
- No clear plan = way more work later.
TDDs might feel like they’re slowing you down, but they’re actually doing the opposite.
The TDD Cheat Sheet
Let me leave you with a little cheat sheet for your next project:
- Start with a TDD, no matter how tempting it is to skip it.
- Keep it simple—focus on clarity over perfection.
- Treat it as your project’s lifeline—not just a formality.
Writing a TDD isn’t just about extra work or good documentation practices. It’s about setting your project up for success from day one.
So, next time you start a project, ask yourself:
Do I want to spend hours debugging later, or minutes planning now?
Your call.
Written by Hasan with 💚
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