Writing less code with Serverless on AWS at AWS Community Day DACH 2021

Writing less code with Serverless on
Vadym Kazulkin, ip.labs, 21 October 2021

Contact
Vadym Kazulkin
ip.labs GmbH Bonn, Germany
Co-Organizer of the Java User Group Bonn
and Serverless Bonn Meetup
v.kazulkin@gmail.com
@VKazulkin
https://www.linkedin.com/in/vadymkazulk
in/
https://www.iplabs.de/

ip.labs
https://www.iplabs.de/

Agenda
• Challenges of the software development
• Serverless and its value proposition
• Dive deeper into “own less, build more” and
“lower technical debt” aspects
• Examples of AWS Serverless services and architectures for
writing less code
• How to be successful with Serverless

Let’s talk about the
challenges of the software
development in general
first

Cognitive Load –
the total amount of mental
effort being used in the working
memory
• Intrinsic
• Extraneous
• Germane

Cognitive Load
• Intrinsic
• How to write a Java class or use a framework
(Spring)
• Extraneous
• Germane

• Intrinsic
• Extraneous
• How to automate tests (unit, integration, end-to-end, web, desktop, mobile)
• How to build, package, deploy and run my application
• How to configure monitoring, alerting, auto-scaling, logging and tracing
• How to operate and maintain infrastructure
• How to build-in fault-tolerance and resiliency
• How to make the hardware, networking and application secure
• Germane
Cognitive Load

• Intrinsic
• Extraneous
• Germane
• Domain Knowledge (payment, e-commerce)
• Business processes and workflows
Cognitive Load

• Intrinsic ->
become fluent in it
• Extraneous ->
minimize amount of what we
implement/operate/support/own by ourselves
• Germane ->
minimize amount of what we have to implement
by ourselves
Cognitive Load

What our boss wants from us?
… that we are productive

Productivity
We are productive if we regularly ship products,
which are successfully used by our customers

What is holding us back from
being productive?
Technical Debt - reflects the implied cost
of additional rework caused by choosing an
easy (limited) solution now instead of using
a better approach that would take longer
”The Cost of Poor Quality Software in the US: A 2018 Report”
https://www.it-cisq.org/the-cost-of-poor-quality-software-in-the-us-a-2018-report/The-Cost-of-Poor-Quality-Software-in-the-US-2018-Report.pdf

Technical Debt
• Even a perfect solution can become the
technical debt over the time
• Version of programming language comes
out of support (Java 8, JS Frameworks)
• Security considerations forces us to
upgrade one of our dependencies (library
or web application server version)
• One of our dependencies (e.g. to open
source project) is discontinued

Think of what can happen to your software
over the entire life cycle of our product
Technical Debt

• is related to amount of code written
• is related to amount of dependencies used
• open source projects, programming
languages, databases, (web) application
servers
Technical Debt

Legacy Systems are systems that can’t
evolve
”The Cost of Poor Quality Software in the US: A 2018 Report”
https://www.it-cisq.org/the-cost-of-poor-quality-software-in-the-us-a-2018-report/The-Cost-of-Poor-Quality-Software-in-the-US-2018-Report.pdf
Legacy System

Evolutionary Architecture–
supports guided, incremental
change across multiple
dimensions
• Incremental change
• Appropriate architectural coupling
• Fitness functions
”Architectural Coupling” https://learning.oreilly.com/library/view/building-evolutionary-architectures/9781491986356/ch04.html

Evolutionary Architecture–
Fitness functions
• Source code metrics (such as measuring
cyclomatic complexity)
• Unit tests (% of coverage and % of success)
• Performance metrics(such as API latency or
throughput)
• Security (encryption at rest, e.g. checking that all S3
buckets have encryption enabled, or automatic key rotation
for all external APIs, with tools such as the AWS Secrets
Manager)
• ArchUnit, Sonar, CI/CD Tools
• CodeCommit,…CodeDeploy, Jenkins
Danilo Poccia „ Serverless + Evolutionary Architectures + Safe Deployments = Speed in the Right Direction”
https://blog.usejournal.com/serverless-evolutionary-architectures-safe-deployments-speed-in-the-right-direction-7b4b01e27254

The Value Proposition of
Serverless
But let’s talk about of Total Cost of Ownership of
the Serverless paradigm

TCO Full Picture
No Infrastructure
Operation and
Maintenance
Auto Scaling and
Fault Tolerance
Built in
Own less,
build more
Lower technical
debt
Faster Time to
Market
Forrest Brazeal „The Business Case For Serverless” https://www.trek10.com/blog/business-case-for-serverless
Focus on Business
Value and Innovation

Own less, build more
By heavily relying on the
managed Serverless services
you
• Can do more with the
same amount of people
• Can more easily evolve
your architecture
Lower technical debt
• Whatever code you write today is always
tomorrow’s technical debt © Paul
Johnston
• Less code means lower technical debt
• Less code means less code maintenance
• Time and effort required for maintaining
the solution over its whole lifecycle is by
far much more than for developing it
Jeff Atwood „The Best Code is No Code At All” https://blog.codinghorror.com/the-best-code-is-no-code-at-all/
Paul Johnston “Cloud 2.0: Code is no longer King — Serverless has dethroned it”
https://medium.com/@PaulDJohnston/cloud-2-0-code-is-no-longer-king-serverless-has-dethroned-it-c6dc955db9d5

Less Lambda functions means less:
• code to write, test, run and maintain
• CI/CD (deploy, rollback strategies) to maintain
• Infrastructure as a Code (IAM policies, permission) to write and test
• cold-start worries
• point of failures and retries
• security concerns
• worries about Lambda limits (e.g. concurrency settings per AWS account)
• spending on Lambda, CloudWatch and 3rd party SaaS on (AWS) (monthly) bill
Sheen Brisals “Don’t wait for Functionless. Write less Functions instead”
https://medium.com/lego-engineering/dont-wait-for-functionless-write-less-functions-instead-8f2c331cd651

• Write fewer Lambda functions
• use more direct service integrations in case the Lambda only calls the
Service itself
• Write less Infrastructure as a Code by using AWS Services/Frameworks
which provide meaningful abstractions
• AWS Amplify and Serverless Framework Components
How to write less code with
AWS Serverless services 2/2

Examples how to write less code with
AWS Serverless services
• API Gateway Service Integration
• HTTP APIs Storage-First Service
Integration
• Step Functions Service Integration
• Step Functions Workflow Studio
• EventBridge with Service Integrations
and API Destinations
• Event Bridge Filtering and Routing
Lambda Destinations
• NoSQL Workbench for DynamoDB
• Export DynamoDB Table Data to S3
• SNS message filtering and native
integration between SNS and
Kinesis Data Firehose
• Amplify Framework
• Serverless Cloud Preview

Sheen Brisals “Don’t wait for Functionless. Write less Functions instead”
https://medium.com/lego-engineering/dont-wait-for-functionless-write-less-functions-instead-8f2c331cd651
API Gateway Service Integration

API Gateway Service Integration with
Dynamo DB : Example ID generator 1/2
Sheen Brisals “Sequence Numbering in Serverless via API Gateway”
https://medium.com/lego-engineering/sequence-numbering-in-serverless-via-api-gateway-40e5f6c83e93
https://github.com/ToQoz/api-gateway-mapping-template

Sheen Brisals “Sequence Numbering in Serverless via API Gateway”
https://medium.com/lego-engineering/sequence-numbering-in-serverless-via-api-gateway-40e5f6c83e93
https://github.com/ToQoz/api-gateway-mapping-template
API Gateway Service Integration with
Dynamo DB : Example ID generator 2/2

Eric Johnson “https://aws.amazon.com/de/blogs/compute/building-storage-first-applications-with-http-apis-service-integrations/”
HTTP APIs Storage-First Service
Integration
• Event Bridge
• Kinesis Data Streams
• SQS
• AppConfig
• Step Functions

Using Service Integrations with EventBridge
“Amazon EventBridge” https://aws.amazon.com/eventbridge/

Using Service Integrations with
EventBridge /Put Targerts
“Amazon EventBridge Put Targets” https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_PutTargets.html

Using API Destinations with EventBridge
“Amazon EventBridge” https://aws.amazon.com/eventbridge/

Using API Destinations with EventBridge
“Using API destinations with Amazon EventBridge”
https://aws.amazon.com/de/blogs/compute/using-api-destinations-with-amazon-eventbridge/

EventBridge Filtering and Routing
“Reducing custom code by using advanced rules in Amazon EventBridge”
https://aws.amazon.com/de/blogs/compute/reducing-custom-code-by-using-advanced-rules-in-amazon-eventbridge/

SNS Message Filtering
https://aws.amazon.com/blogs/compute/simplify-pubsub-messaging-with-amazon-sns-message-filtering/

Native integration between SNS and
Kinesis Data Firehose
https://aws.amazon.com/de/blogs/compute/introducing-message-archiving-and-analytics-for-amazon-sns/

Step Functions Service Integration
“Service Integrations with AWS Step Functions” https://docs.aws.amazon.com/step-functions/latest/dg/concepts-service-integrations.html

AWS Step Functions Supports 200
AWS Services
https://aws.amazon.com/de/blogs/aws/now-aws-step-functions-supports-200-aws-services-to-enable-easier-workflow-automation/
arn:aws:states:::
aws-sdk:serviceName:apiAction.
<serviceIntegrationPattern>

Step Functions Workflow Studio – A Low-Code
Visual Tool for Building State Machines
“AWS Step Functions Workflow Studio”
https://aws.amazon.com/de/blogs/aws/new-aws-step-functions-workflow-studio-a-low-code-visual-tool-for-building-state-machines/

Lambda Destinations
“Introducing AWS Lambda Destinations” https://aws.amazon.com/de/blogs/compute/introducing-aws-lambda-destinations/
https://www.trek10.com/blog/lambda-destinations-what-we-learned-the-hard-way

NoSQL Workbench for DynamoDB
https://aws.amazon.com/dynamodb/nosql-workbench/
Data Modeling Data Visualization Operation Building

Export DynamoDB Table Data to S3
https://aws.amazon.com/de/blogs/aws/new-export-amazon-dynamodb-table-data-to-data-lake-amazon-s3/

Amplify
“Amazon Amplify” https://aws.amazon.com/amplify
Amplify supports :
• web frameworks including JavaScript, React, Angular, Vue, Next.js
• mobile platforms including Android, iOS, React Native, Ionic, Flutter

Amplify and Admin GUI
https://docs.amplify.aws/console/adminui/intro#access-outside-the-aws-management-console/

AWS Amplify managed CI/CD
https://towardsaws.com/step-by-step-guide-to-deploy-your-web-application-with-auto-ci-cd-pipeline-using-aws-amplify-a87712756c2

Serverless Cloud Preview
https://www.serverless.com/blog/introducing-serverless-cloud-public-preview

Common patterns
• Direct service integrations to reduce the amount of code written
• API Gateway, HTTP API, Step Functions, EventBridge, SNS,
Amplify
• Visual Studio/Tools to reduce the cognitive load
• Step Functions, Amplify, DynamoDB
• Automated CI/CD to focus on the business logic
• Amplify, SAM
• First steps in interpreting Infrastructure from Code
• Serverless Cloud

Using Serverless ecosystem will
with the right engineering practices in place will significantly reduce
• extraneous and germane cognitive load
• the amount of code written
• the amount of dependencies (no execution runtime and web application server to
take care of)

Reducing dependencies doesn’t mean that you own nothing (you still
own things, but in general less)
• Lambda language runtime version will be retired from time to time
• Node.js <10.x, Java 8 runtime migration to Amazon Corretto
• Aurora with PostgreSQL/MySQL compatibilities will force you to
upgrade database version behind
• Retiring PostgreSQL version 9.6
plan and execute upgrades continuously and iteratively
Word of caution about the
Serverless ecosystem

How to be successful with Serverless

How to measure success
Let’s focus on software delivery and operational performance
(how to do the things right)
• Provide the managers and executives metrics, that we’re on the right path
• See from the developer’s perspective how to achieve it and improve
It’s also important to the right thing!

How to measure success
See DORA State of DevOps 2018-2019 Reports

Software Delivery and
Operational Performance

Example: strategies to reduce
time to restore service

Blue-Green
deployment
“Win-Win Deployment Strategies for Modern Apps” https://rollbar.com/blog/deployment-strategies/
Canary
deployment

AWS Lambda Deployment
Best Practices:
• API Gateway Stage variables and
Lambda Aliases
• Lambda Alias Traffic Shifting
Chris Munns: “Testing and Deployment Best Practices for AWS Lambda-Based Applications”
https://www.youtube.com/watch?v=zJQDAsWm-5k&list=LLYgjRSI2oCzI9eooyFrWR7A&index=1

AWS Lambda Deployment
Best Practices
• AWS Lambda Alias Canary and Linear Traffic
Shifting & AWS SAM Safe Deployments
• CloudWatch Rollback Alarms & Lambda hooks
Chris Munns: “Testing and Deployment Best Practices for AWS Lambda-Based Applications”
https://www.youtube.com/watch?v=zJQDAsWm-5k&list=LLYgjRSI2oCzI9eooyFrWR7A&index=1

Think of different versions of business logic (Lambda) working correctly with
the persistent layer (S3, EFS, RDS, Serverless databases f.e. Aurora and
DynamoDB) behind
• Do not make not backward compatible changes in the file format on the
storage
• Do not make not backward compatible changes to the database structure
• Do not rename table columns
• Do not add new NOT NULL column into the database table
Word of caution about the Blue-Green
and Canary Serverless deployments

Wardley Maps
Simon Wardley https://www.slideshare.net/swardley/why-the-fuss-about-serverless-88107645
Co-evolution of practices
to become productive with
Serverless

Co-evolution of practices with
Serverless 1/2
• True DevOps
• Complete infrastructure automation
• Chaos Engineering
• FinDev responsibilities in the teams
Sheen Brisals “Why the ‘WHY’ matters more than the ‘WHAT’ in Serverless!”
https://medium.com/lego-engineering/why-the-why-matters-more-than-the-what-in-serverless-2ef56c397962
DevOps Topologies: https://web.devopstopologies.com/

• Each team or even developer can have its own
(AWS test) account per feature or service
• Only minimal local testing (quick functional tests)
• Adopt “testing in production”
Michael Bryzek “What do you know about testing in production?” https://www.youtube.com/watch?v=z-ATZTUgaAo
Co-evolution of practices with
Serverless 2/2

Writing less code with Serverless on AWS at AWS Community Day DACH 2021

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