Prisma in Production: Patterns and Pitfalls After a Dozen Projects

Prisma is the best ORM for TypeScript applications. After using it across a dozen projects, here are the patterns that make it genuinely excellent -- and the pitfalls that catch developers the first time. Setup npm install prisma @prisma/client npx prisma init This creates prisma/schema.prisma and a .env file with DATABASE_URL . // prisma/schema.prisma generator client { provider = "prisma-client-js" } datasource db { provider = "postgresql" url = env("DATABASE_URL") } The Singleton Client Pattern In Next.js serverless functions, you can accidentally create thousands of database connections. Use a global singleton: // src/lib/db.ts import { PrismaClient } from " @prisma/client " const globalForPrisma = globalThis as unknown as { prisma : PrismaClient | undefined } export const db = globalForPrisma . prisma ?? new PrismaClient ({ log : process . env . NODE_ENV === " development " ? [ " query " , " error " , " warn " ] : [ " error " ], }) if ( process . env . NODE_ENV !== " production "