07. Integration & The Glue
by ai • January 7, 2026
Putting the Pieces Together
At this point, you have a Dining Room (Frontend), a Kitchen (Backend), a Pantry (Database), and a Cashier (Payments). Integration is the process of making sure they all talk to each other without errors.
1. The Full Stack Workflow
When a user signs up for your SaaS, a "chain reaction" happens:
The Frontend collects the email and password.
The API sends that data to the Backend.
The Backend checks if the email is already taken. If not, it "scrambles" the password (hashing) and saves it to the Database.
The Backend then tells Stripe to create a new customer record.
The Backend sends a "Success" message back to the Frontend.
The Frontend redirects the user to the "Welcome" dashboard.
This flow must be seamless. If one link breaks, the whole machine stops.
2. Environment Variables (The Secret Vault)
Your app needs "keys" to talk to other services (like Stripe or your Database). You must never put these keys directly in your code. Instead, you use Environment Variables (often stored in a .env file).
Think of these as a "Secret Vault."
Your code says, "Go get the Stripe Key from the vault."
This keeps your keys safe even if you share your code with others.
3. Types of Apps: One Logic, Many Screens
A true SaaS product often needs to live on more than just a website.
Web Apps: These run in the browser (like Chrome). They are the easiest to build and update.
Mobile Apps (iOS/Android): These are installed on a phone. You can use tools like React Native to use your existing JavaScript skills to build these.
Desktop Apps: These live on a computer (like Slack or Discord). Tools like Electron allow you to turn your web app into a desktop app.
The best part - if you build your Backend API correctly, all three versions (Web, Mobile, Desktop) can talk to the same kitchen and use the same pantry.
4. The "Glue" Tools (Zaper, Webhooks, Cron Jobs)
Sometimes you need your app to do things automatically:
Webhooks: As discussed, these let outside services (like Stripe) "call" your app when something happens.
Cron Jobs: These are "Scheduled Tasks." For example, every Monday at 9:00 AM, your server runs a script to send a "Weekly Summary" email to all users.
Next Lesson -> 08. AI & Future-Proofing