How to Build Serverless Functions
Create and deploy serverless functions for APIs, webhooks, and background processing.
What You'll Learn
This beginner-level guide walks you through how to build serverless functions step by step. Estimated time: 8 min.
Step 1: Choose your platform
Select Vercel Edge Functions, AWS Lambda, or Cloudflare Workers based on your hosting and use case.
Step 2: Write your first function
Create a serverless function that handles HTTP requests, processes data, and returns responses.
Step 3: Add database connectivity
Connect to databases using connection pooling to handle the stateless nature of serverless functions.
Step 4: Handle cold starts
Minimize cold start impact with smaller bundles, provisioned concurrency, or edge runtime deployment.
Step 5: Monitor and debug
Set up logging, error tracking, and performance monitoring for your serverless functions.
Frequently Asked Questions
When should I use serverless?▾
Serverless is ideal for APIs, webhooks, cron jobs, and event processing. Use containers for long-running processes or WebSocket connections.
How do I handle database connections?▾
Use connection pooling (PgBouncer, Prisma Accelerate) since serverless functions create new connections per invocation.
What about cold starts?▾
Edge Functions have near-zero cold starts. Lambda cold starts are 100-500ms. Keep bundles small and use provisioned concurrency for latency-sensitive endpoints.