Why Serverless for SaaS?
When building a SaaS product, your infrastructure costs should scale with your revenue — not against it. AWS serverless architecture gives you exactly that: you pay per request, scale to zero when idle, and never manage a server.
At Zyron Technologies, every SaaS product we build starts with a serverless-first mindset. Here's the stack we use and why.
The Core Stack
AWS Lambda + API Gateway
Lambda is the backbone. Each API route maps to a Lambda function — isolated, independently deployable, and infinitely scalable.
// A simple Lambda handler in TypeScript
export const handler = async (event: APIGatewayProxyEvent) => {
const body = JSON.parse(event.body ?? "{}");
return {
statusCode: 200,
body: JSON.stringify({ message: "Hello from Lambda" }),
};
};
DynamoDB for the Database
Single-table design with DynamoDB gives you predictable latency at any scale. The key is getting your access patterns right before you design your table.
AWS CDK for Infrastructure
We write all infrastructure as TypeScript code using AWS CDK. No clicking in the console, no drift, full version control.
const api = new aws_apigateway.RestApi(this, "Api", {
restApiName: "zyron-saas-api",
defaultCorsPreflightOptions: { allowOrigins: ["*"] },
});
Multi-Tenancy Patterns
For SaaS, multi-tenancy is non-negotiable. We use tenant ID as a partition key prefix in DynamoDB:
PK: TENANT#acme SK: USER#john
PK: TENANT#acme SK: SUBSCRIPTION#pro
This keeps tenant data isolated without separate databases per tenant.
Cost at Scale
A SaaS product on this stack with 10,000 active users typically costs under $50/month in AWS infrastructure. Compare that to EC2 or ECS running 24/7.
When NOT to Use Serverless
Serverless isn't always the answer. Avoid it for:
- Long-running jobs (>15 minutes) — use ECS Fargate instead
- Websockets with high connection counts — use API Gateway WebSocket APIs carefully
- Heavy CPU workloads — Lambda cold starts hurt here
Getting Started
If you're building a SaaS product and want AWS serverless done right, book a free call with our team. We've shipped 50+ serverless projects and can help you avoid the common pitfalls.