That app idea in your head? The one with user accounts, a database, maybe payments? You've been putting it off because you don't know where to start—not just the coding, but the entire process.

The process matters more than the code. Once you understand the systematic approach, AI can help you implement each step.

The Tech Stack

Building web apps involves choosing from many technologies: programming languages (JavaScript, Python, PHP, Ruby), frameworks (Next.js, Django, Laravel, Ruby on Rails, Angular), and databases (PostgreSQL, MySQL, MongoDB). We're choosing the following stack because it's the most popular, has extensive learning resources, and is flexible enough to build almost any idea you can think of—from simple tools to complex SaaS applications.

AI Coding Setup Options

The right AI coding setup is your secret weapon. It turns hours of work into minutes—writing components, debugging errors, and navigating unfamiliar codebases becomes almost effortless. Here are our recommended setups:

The 5-Step Workflow

Now that you have your tools ready, here's the systematic process we'll follow. Each step builds on the previous one—skip nothing, and you'll have a production-ready app.

Key insight: Build one well-tested feature at a time. Deploy it. Move to the next.

Most people skip this and jump straight into coding. Big mistake.

Define Your MVP

Open ChatGPT or Claude and have a real conversation:

After brainstorming, get specific:

Example MVP Breakdown

Build later: Advanced analytics, social features, custom reminders, mobile apps. Ship the MVP first, then add these based on user feedback.

Document Your Data Model

AI will provide something like:

Prerequisites

Before building anything, you need a few essential tools. Node.js runs your development server and manages packages. Git tracks code changes and connects to GitHub for version control. Your AI coding tool (Cursor or VS Code with Claude Code) writes most of the code. The Supabase CLI lets you run a local database and manage migrations. Finally, you'll need a GitHub account to store your code and connect to deployment platforms like Vercel or Netlify.

Create Your Project

Let's scaffold a new Next.js application with all the modern defaults we need.

Install Dependencies

We'll install the Supabase client libraries for database and authentication. For UI components, we recommend Shadcn/ui—it gives you beautifully designed, accessible components that you own and can customize. Feel free to use another UI library if you prefer.

Set Up Git

Version control is essential. Initialize Git and connect to a remote repository to keep your code safe and enable collaboration.

Supabase: Three Environments

We recommend setting up three separate database environments from the start. This keeps your development experiments isolated from real user data and gives you a safe place to test changes before they go live.

Environment Variables

Environment files store sensitive configuration like API keys and database URLs. You'll have one file per environment. While we're starting with Supabase credentials, you'll add other variables here as your app grows (API keys, feature flags, etc.)—more on this later.

Create three files in your project root:

How to switch between environments

Local development (default):

• Next.js automatically uses .env.local when you run npm run dev
• Your app connects to your local Supabase instance

Testing with staging database locally:

• Temporarily rename .env.staging to .env.local
• Run npm run dev to test against your cloud staging database
• Rename back to .env.staging when done

Deploying to Vercel or Netlify:

• Copy your environment variables to your hosting provider's dashboard
• We'll cover the full deployment workflow later in this guide

Understanding Migrations

The workflow:

1. Develop locally with local Supabase
2. Create a migration file for schema changes
3. Push migrations to staging, test
4. Push migrations to production

Applying Migrations

Once you've created a migration file, you need to apply it to your databases.

Create Layout Structure

Every page in your app will share a common layout—navbar, footer, and content area. Let's create this foundation first so all future pages automatically inherit it.

Set Up Authentication

Supabase offers many authentication methods—OAuth providers (Google, GitHub, etc.), Magic Links, email/password, and more. To keep things simple, we recommend:

• Google Login — The most popular option. Users click one button and they're in. No passwords to manage.
• Magic Link (optional) — For users who prefer email. They enter their email, receive a link, click it, and they're logged in. No password needed.

Configure Supabase Auth

Create Auth Pages

With Google and Magic Link, you only need a simple login page—no separate signup or password reset flows to build. Users are automatically created in Supabase on their first login.

Protect Routes with Middleware

Next.js middleware runs before every request, making it the perfect place to check authentication. If a user tries to access a protected page without being logged in, they'll be redirected to the login page.

Test Authentication

Before moving on, verify that authentication works end-to-end. This is one of those things you want to get right early—debugging auth issues later is painful.

Git Workflow

Before diving into features, let's establish a Git workflow that works with our two Supabase environments (staging and production).

Branch Strategy

We use two long-lived branches, each connected to its own database:

main (production) ← dev (staging) ← feature branches
     ↓                  ↓
 Prod Supabase    Staging Supabase

• main — Production code, deployed with production Supabase
• dev — Staging code, deployed with staging Supabase
• Feature branches — Your work in progress, tested locally

For each feature:

1. Create a feature branch from dev
2. Build and test locally with local Supabase
3. Merge to dev and test on staging with cloud staging Supabase
4. When stable, merge dev to main for production release

Set Up Vercel or Netlify

Before building features, connect your repository to a hosting provider. You only need one project — it automatically handles staging vs production deployments.

How Environment Variables Work

Vercel and Netlify assign environment variables by deployment type, not branch name:

Configure Environment Variables

Add your Supabase credentials separately for Preview (staging) and Production:

In Vercel: Settings → Environment Variables → Add each variable and select which environments it applies to.

In Netlify: Site settings → Environment variables → Create variable with different values per deploy context.

The result:

• dev branch → Preview URL (your-app-git-dev.vercel.app) → staging Supabase
• main branch → Production URL (yourapp.com) → production Supabase

Same codebase, different configs, fully isolated.

The Feature Development Cycle

For every feature, follow this process:

Example: Building Habits CRUD

Let's walk through the cycle with our first real feature—the ability to create, read, update, and delete habits. This is the core of our app.

Step 1: Plan Feature & Data Model

Before writing code, get clear on what you're building. Spend 10-30 minutes thinking through the user experience and data requirements.

Feature scope:

• Users can create habits with a name and optional description
• Users see all their habits in a list
• Users can edit or delete any habit
• Each user only sees their own habits (data isolation)

Data model — habits table:

Step 2: Create Migration

Now translate your data model into a database migration. This creates the actual table in your database.

supabase migration new create_habits_table

Step 3: Create API Routes

With the database ready, create the API endpoints that your frontend will call. These handle all the business logic and database operations.

Step 4: Implement UI

Now build the user interface. This is where users actually interact with your feature—make it intuitive and responsive.

Step 5: Manual Testing

Before automating anything, click through the feature yourself. Find and fix obvious bugs now—it's faster than debugging failing tests later.

Step 6: Write Tests

Once everything works manually, write tests to lock in the behavior. Tests catch regressions when you add new features later.

One-Time Setup

Install the testing libraries (you only do this once per project):

npm install -D vitest @testing-library/react @testing-library/jest-dom jsdom
npm install -D @playwright/test
npx playwright install

Unit Tests

Unit tests verify individual pieces work correctly in isolation. They're fast and run without a browser.

Expected output: Test files in __tests__/ or *.test.ts files next to your API routes. Each test mocks Supabase responses and verifies your route handlers return correct data and status codes.

E2E Tests

E2E (end-to-end) tests simulate real users clicking through your app in an actual browser. They're slower but catch integration issues.

Expected output: Test files in e2e/ or tests/ folder. Playwright launches a real browser, navigates to your app, fills forms, clicks buttons, and asserts the UI updates correctly.

Running Tests

npm run test        # Unit tests (fast, no browser)
npx playwright test # E2E tests (launches browser)

Step 7: Deploy

Feature complete and tested locally? Time to ship it.

Merge to dev (deploys to staging):

# First, push migration to staging database
npx supabase link --project-ref <staging-ref> && npx supabase db push

# Then merge and push
git checkout dev && git merge feature/habits-crud && git push origin dev

Test on your staging URL. Once it works, promote to production:

Merge dev to main (deploys to production):

# First, push migration to production database
npx supabase link --project-ref <prod-ref> && npx supabase db push

# Then merge and push
git checkout main && git merge dev && git push origin main

You've built features, tested them on staging, and deployed to production. Now it's time to launch properly.

Custom Domain

Connect your own domain to make your app feel professional.

Pre-Launch Checklist

Before announcing to the world, verify these basics:

Monitoring

Once your app is live, you need visibility into errors and user behavior. These tools have free tiers for small apps.

Error tracking — Know when things break before your users tell you:

Analytics — Understand how users interact with your app:

Advanced Topics

Working Effectively with AI

AI Strengths vs Your Judgment

Project Rules Files

Most AI coding tools let you store project context in a rules file. This gives the AI knowledge about your stack, conventions, and patterns—so you don't have to repeat yourself in every prompt.

What to include in your rules file:

Effective Prompting

What You've Learned

You now understand:

• The complete workflow from idea to production
• How to use AI assistants effectively for each phase
• The importance of testing and systematic deployment
• Database migrations and version-controlled schemas
• Three-environment strategy (local, staging, production)
• Iterative feature development with proper validation

More importantly: You have a repeatable process. Every app follows this pattern.

Next Steps

Pick a project that matches your current skill level and build it end-to-end using this guide.

Last updated: December 2024

Resources

• Next.js Docs | Supabase Docs | Tailwind CSS
• Vitest | Playwright
• Cursor | Anthropic Prompt Engineering