Learn S3 signed URLs from our free email-based course
Learn the basics of cloud-native file handling:
Why serverless needs a new way to distribute files
How to implement signed URLs on the backend and the frontend
How permissions work with signature-based downloads
Tamás Sallai
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Learn how to use CloudFront from our free email-based course
Learn the basics of CloudFront configuration and:
Take advantage of AWS's global distribution network
Use path-based routing to add an entry point to your cloud infrastructure
Utilize caching on the edge locations
Tamás Sallai
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Learn how to use async functions in Javascript from our free email-based course
Learn the basics of async/await and master asynchronous workflows in Javascript.
Learn:
How async functions work and how to use the await keyword
How to use the Promise constructor
How to implement proper error handling in an async environment
Tamás Sallai
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Learn the basics of serverless computing on AWS from our free email-based course
Learn the parts that are needed to make a serverless API on AWS:
Write a Lambda function and add IAM permissions to it
Add API Gateway for an HTTP endpoint
Use DynamoDB to store data
Tamás Sallai
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Join our mailing list
We write articles like this regularly. Let's keep in touch and:
Get coupons for our books and courses when they are available
Download our short ebook on AWS security basics
Get articles and content on a regular basis
AWS S3 Signed URLs Handbook free chapters
Thank you for your interest in the book! By signing up to the free chapters you'll receive 4 emails, each with a different part of the book.
The included chapters:
Introduction and use cases
The architecture of signed URLs
Backend implementation with Node.js
Least privilege with dedicated roles
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Javascript on AWS Lambda free chapters
Thank you for your interest in the book! By signing up to the free chapters you'll receive 4 emails, each with a different part of the book.
The included chapters:
Introduction and the Lambda execution model
Cold starts
Async programming model
Storing secrets in SSM Parameter Store
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
A Practical Guide to AWS IAM free chapters
Thank you for your interest in the book! By signing up to the free chapters you'll receive 4 emails, each with a different part of the book.
The included chapters:
Introduction and Access control basics
IAM users and roles
The Principal and the Resource fields in policies
Resource-based policies
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Asynchronous Programming Patterns in Javascript free chapters
Thank you for your interest in the book! By signing up to the free chapters you'll receive 4 emails, each with a different part of the book.
The included chapters:
Introduction
Getting started with async/await
Error propagation in Promise chains
The async disposer pattern
Getting an "already subscribed" error?
This also signs you up to our mailing list (Why is that?).
Javascript functions on AWS Lambda
Serverless computing allows scalability from zero to practically infinity. Inside AWS, Lambda is the key service to run functions.
But while the code is in a familiar language, the runtime environment, the connected services, and the best practices are all different than in server-based architectures.
Learn how to write Javascript functions for the AWS Lambda environment.
Want a sneak peek? Sign up for free chapters here:
It's a whole ecosystem
A Lambda function is just one piece of the serverless puzzle, as it needs other services to be useful. It can't even store its logs but sends them to a separate service inside AWS.
It gets its permissions via an IAM Role, puts its metrics and logs to CloudWatch and X-Ray, and integrates with API Gateway to provide an HTTP endpoint. S3 is the choice to store files, and for secret configuration values, you can use SSM Parameter Store.
A Lambda function integrates with these services in different ways and each of them brings complications to the mix. But a serverless success story depends on using the full ecosystem.
Lambda is a different environment than an EC2 instance
The serverless runtime environment is radically different than traditional, on-server, architectures. It brings the promise of infinite scalability, but also new problems to solve.
The problem of cold starts, the retrying model, the ephemeral local storage, and other properties of the Lambda model are all problems you need to be aware of to develop and deploy functions with success.
And it also affects how to write Javascript code to it, such as how best to initialize variables and how to use async/await.
Learn how to implement Javascript functions
This book has all the information to write Lambda functions in Javascript effectively. You'll learn:
How the Lambda runtime environment works
How to write and deploy Javascript functions
How to integrate the function with other services
Debugging Lambda
Add an HTTP API
...and more!
Screenshots
Table of contents
The Lambda execution model Serverless functions Limits The cost model At-least-once execution Caching in /tmp Cold start Memory
Setup Node versions The Lambda permission model How to define code Inline code File interpolation Adding packages with npm Handler argument
Programming model Async handler Async programming patterns Background tasks Input and output The event object The context object Output The AWS SDK Pagination Environment variables Timeout Cause of timeouts Mitigating timeouts AWS SDK timeouts Promise-based timeout handling
Debugging Logging X-Ray Custom segments
Other topics Storing secrets Using SSM Caching Cache time HTTP API OpenAPI backend Request parameters Special handlers Express backend
About the author
Tamás Sallai
Hey, I'm Tamás! I co-author the advancedweb.hu blog and if you're here there is a good chance you've already read some of my articles.
I'm a software developer focusing mostly on cloud computing and web technologies. I'm especially interested in how to handle edge cases to end up with dependable software.
One of my main focus is security and how each part affects the whole system. I'm an AWS-certified security specialist.
Tamás Sallai 
