Serverless Backend Patterns Cheat Sheet

Serverless backend patterns enable event-driven, scalable application architectures where cloud providers manage infrastructure, allowing developers to focus on business logic while paying only for actual compute time. These patterns—built primarily on AWS Lambda, Azure Functions, and Google Cloud Functions—provide automatic scaling, high availability, and reduced operational overhead for modern cloud-native applications. The key to successful serverless backends lies in understanding function invocation models, optimizing cold start performance, designing stateless workflows, managing dependencies and secrets, and implementing robust error handling with idempotent operations. Lambda's 2025 releases—including Durable Functions for checkpoint-based long-running executions, Managed Instances for EC2-backed steady-state workloads, and Tenant Isolation Mode for SaaS multi-tenancy—have significantly expanded what serverless can do, while the rise of AI agent patterns makes Lambda an increasingly central compute layer for agentic architectures.