Welcome to the first official technical post of our series, The Everyday Backend Engineer: Practical Design Patterns. We are kicking things off with a Creational Pattern that every backend developer uses (or should be using) to protect system resources and prevent server crashes: The Singleton Pattern.
Let’s break it down using a practical backend approach: the problem, the real-world analogy, and a clean Node.js solution.
Imagine you are building an Express.js API, and every time a user hits a route to fetch data, you spin up a brand new database connection inside the controller or service file:
// ❌ Bad Practice: Creating a new connection on every request
app.get('/users', async (req, res) => {
