How do you manage a database connection efficiently across many requests in a serverless Next.js deployment?

In serverless environments, creating a new database connection on every single request can quickly exhaust the database's connection limit, so you typically use a connection pooler or reuse a single client instance across requests by attaching it to a global variable during development.

// lib/db.js
let db;
if (process.env.NODE_ENV === 'production') {
  db = new PrismaClient();
} else {
  if (!global.db) global.db = new PrismaClient();
  db = global.db;
}

export { db };