AWS Serverless at Qest

Why AWS?

Customer-centric philosophy
Lead in cloud & serverless
Tooling & OSS

Serverless

no servers to manage
implicitly highly available & scalable
pay-per-request pricing model
logging & monitoring built-in

Pay-per-use pricing +
High-level tooling +
High-level services = Cloud-native Serverless

Multiple environments / versions no longer cost more
- sandbox environment for each developer
Velocity - focus on solutions, not server management
- production-grade prototypes
Custom tooling & services on top of existing ones
- cloud as a framework

Basic serverless application components

Messaging

Compute

Storage

Identity

DynamoDB

Lambda

SQS

SNS

Cognito

Integration

API Gateway

Cloudfront

Cognito UserPool

Secure identity provider
Deep integration with other services

Cognito IdentityPool

Enables user access to AWS resources for configured identity providers

AWS Lambda

Hosted piece of code, that handles events
- limited time of execution (15min)
Pricing in 100ms increments
- based on configured memory
Many event sources
Integration-specific return values

module.exports = async (event) => {
    return {
        statusCode: 200,
        body: "success",
    };
};

DynamoDB

Infinitely scalable key-value database
- at consistent latency
- ideal for customer-facing scenarios
Pay-per-request + storage
Many weird quirks and specifics
- read docs first
DynamoDB Streams
- serves as an integration point

SNS / SQS

SQS - fully-featured queue with unlimited throughput
- buffering
- offloading work
SNS - notification system with pub/sub semantics
- organized into Topics
- integration

Serverless application design

Organizing application into contexts - custom sources of events.

Microservice Service Context

Case Study

Abaku

Integrating Service Contexts

EventBridge
- Decoupling event sources / targets
AWS Step Functions
- workflow orchestration

EventBridge

Step Functions

Business use cases that cross contexts
- need to know the state even in case of a failure
Pay for state transitions
- and underlying resources

Qest Serverless Workshop

By Vít Habada