How to avoid going crazy
when composing
serverless applications?
Rafał Gołubowicz

Rafał Gołubowicz
- Senior Node.js Developer in The Software House
- Experience with plenty of Backend and Frontend
technologies
- fan of cloud solutions (AWS Certification soon ^^)
- enthusiast of new technologies and simple,
unconventional solutions
- speaker, trainer, mentor
- loves travels, robotics, good books, ukulele and
whisky

Serverless? What's all that noise about?
Serverless architecture is a way to
build and run applications and
services without having to manage
infrastructure. Application still runs
on servers, but all the server
management is done by provider.
You no longer have to provision,
scale, and maintain servers to run
your applications, databases, and
storage systems.
Source: https://www.ebcgroup.co.uk/news-insights/on-premises-vs-cloud

How it works?
1. The developers write a function.
2. The developers define an event. (ex. HTTP - GET
method)
3. The developers can define authorizers. (ex. JWT)
4. The event gets triggered.
5. The server authenticates API request (if added).
6. The function gets executed.
7. The result gets sent to the user.

Why should we use it?
- reduced costs - no need to run 24/7 server,
charge only for the time the function was
running.
- great scalability
- easier to introduce new features
- quick deployment
- less effort for infrastructure maintenance

Serverless - use cases
● processing images,
● triggering actions based on various events,
● backend API,
● asynchronous jobs,
● scheduled tasks,
● notifications,
● advanced business workflows

AWS (Amazon Web Services) is a cloud service provider
that offers various computing services that are
accessible over the public internet.
AWS manage and maintain hardware and infrastructure,
saving organizations and individuals the cost and
complexity of purchasing and running resources on site.
These resources may be accessed for free or on a
pay-per-use basis.
Presentation is based on the AWS solutions.
AWS Serverless

Sample business
process

I want to increase my
credit limit!

Clients ask to increase
credit limit
Increase credit line process
1 2
Bank reviews client
income and history
● Fill out the application form ● Verify the application
● Determine the creditworthiness
● Check credit history
● Increase the credit limit
● Send decision to the client
3
Client got a decision
● Receive a decision

Do we need an
architecture diagram?

YES.

Architecture diagram advantages
● makes it easy to discuss architecture by the team,
● better understanding system for anyone involved in the project
(including non-technicals),
● helps developers while creating,
● easier to onboard new developers.

AWS Console

AWS Console
- set up other services,
- set up IAM policies,
- set up VPC,
- test functions on the AWS console.
- And… remove everything manually (if needed) :-)

Serverless
framework

Serverless Framework
Serverless Framework is open source software that
builds, compiles, and packages code for serverless
deployment, and then deploys the package to the cloud.
Serverless Framework helps with development by
emulating the Lambda environment. Thanks to many
external plugins, it could emulate plenty of serverless
services (like AWS Step Functions, AWS API Gateway,
etc..). Developer is able to test the each part of
application before deploying it to the cloud.

Infrastructure as Code
Infrastructure as Code (IAC) is a way to manage
services and networks using code instead of
manual work. This means that instead of setting
up everything by clicking on AWS Console, you
can write the code that describes how the
system should be set up and then use tools to
automatically configure the system based on
that definition. This makes it faster and easier to
set up and manage computer systems, and also
makes it easier to work together as a team.

Serverless framework configuration - header

Serverless framework configuration - provider

Serverless framework configuration - Lambda functions

Serverless framework configuration - Step Function

Serverless framework configuration - workflow definition

Serverless framework
deployment

sls deploy —stage=dev

sls deploy function -f verifyApplication

Composing Serverless Framework services

Serverless Framework
And it’s just a chunk of
possibilities with serverless
framework offers….

AWS SAM
+
App Composer

AWS Serverless Application Model

AWS App Composer is a new low-code tool for
visually designing and building serverless
applications. It was announced at the re:Invent
conference in December 2022. The service
provides developers with a visual canvas and a
simple drag and drop interface to create
serverless architecture, connect resources and
design the functions.
AWS Application Composer

AWS Application Composer - build infrastructure

AWS Application Composer - generated CF

AWS Application Composer - issues
● lack of AWS services
● duplication of sections in CloudFormation
● missing important configuration
● making mess in local project
● for the rest of issues check out my latest post on TSH.io/blog

AWS Console Serverless Framework AWS App Composer + AWS SAM
- only AWS
- development by managing resources in the
dashboard
- doesn’t support TS
- visual designers for SFN; process can be
made by drag and drop; no need to know
CloudFormation
- needs to remove everything manually
- supports multi providers
- regular development, most of features can be
tested locally
- supports TS
- a little familiarity with AWS CloudFormation or
AWS resources (to know properties/settings)
- 1 command to deploy or remove everything
- used by many companies;
- only AWS
- regular development, most of features can be
tested locally
- supports TS
- visual designer, can be connected with local
environment; no need to know CloudFormation
- 1 command to deploy or remove everything
- AWS App Composer is a preview feature

tsh.io
Thanks for your attention!
Rafał Gołubowicz
Senior Node.js Developer