In this talk, we will look at how to reduce backend complexity by using a service from AWS called AWS AppSync. AWS AppSync is a fully managed GraphQL service that hooks into other AWS resources easily. We will also talk about how to deploy AWS AppSync using the AWS AppSync Serverless Framework Components. Full video will be hosted on the Serverless Guru Training Site, training.serverlessguru.com.

1. A talk on
AWS
AppSync
Reducing backend
complexity

2. Serverless Guru
Founder & CEO at Serverless Guru
Senior Cloud Developer at Mode2
Application Engineer at Nike
Innovation Engineering
Department
History:

3. What is AWS?
“Amazon Web Services is a subsidiary of Amazon that provides
on-demand cloud computing platforms to individuals, companies,
and governments, on a metered pay-as-you-go basis.”
- Wikipedia
Serverless Guru

4. What is AWS API Gateway?
AWS API Gateway is a fully managed REST API service that
allows you to easily create API endpoints that connect directly to
AWS Lambda functions.
Serverless Guru

5. Serverless Guru

6. REST APIs with AWS API Gateway
● Easy to set up & start
● Less automation required
● Solved thousands of times
● Lots of tutorials
● No built-in documentation
● Porting Swagger and connecting
to AWS Lambda functions is a
nightmare
Pros Cons
Serverless Guru

7. What is AWS AppSync?
“A fully managed serverless GraphQL service for real-time data
queries, synchronization, communications, and offline
programming features.”
- Tara Walker, Technical Evangelist
Serverless Guru

8. What is GraphQL?
“GraphQL is a responsive data query language and server-side
runtime for querying data sources that allow for real-time data
retrieval and dynamic query execution.”
- Tara Walker, Technical Evangelist
Serverless Guru

9. What is a GraphQL Schema?
“GraphQL works at the application layer and provides a type
system for defining schemas. These schemas serve as
specifications to define how operations should be performed on
the data and how the data should be structured when retrieved.”
- Tara Walker, Technical Evangelist
Serverless Guru

10. GraphQL APIs with AWS AppSync
● Built-in Documentation
● Connect to other AWS resources
easily
● Create VTL files to write directly to
AWS DynamoDB without a
Lambda function in between
● AppSync suggests best practices
● Support for subscribers for real-
time communication
● Hard to do more advanced things
● More difficult to quickly create a
POC
● VTL files are a nightmare
● *Automation is much more
involved
Pros Cons
Serverless Guru

11. Serverless Guru

12. AWS AppSync Key Concepts
● GraphQL schema is attached to AWS AppSync
● Resolvers are linked to Data Sources and GraphQL data types
● Data Sources like databases, AWS Lambda, HTTP endpoints are
connected to resolvers
● VTL (Velocity Templating Language) files can remove the need for
AppSync to be connected directly an AWS Lambda function
Serverless Guru

13. ChatQL Example
Source: AppSync, product pageServerless Guru

14. Deploy AppSync
Serverless Guru

16. Serverless Guru Source: Serverless Framework
AWS Lambda (serverless.yml)

17. Serverless Guru Source: Serverless Framework
GraphQL Schema (schema.graphql)

18. Serverless Guru Source: Serverless Framework
AppSync API (serverless.yml)

19. Serverless Guru Source: Serverless Framework
AppSync Data Sources (serverless.yml)

20. Serverless Guru Source: Serverless Framework
AppSync Mapping Templates (serverless.yml)

21. A basic example of
how you would
make a request to
your AWS AppSync
API
Source:
Serverless Framework

22. CRUD APIs Without Code
Serverless Guru

23. VTL Mapping Templates (the magic)
● Leveraging VTL files we can remove A LOT of API code
● *All CRUD functionality can be replaced with VTL files
● AWS has their own VTL specific packages to allow the developer to
do for loops, set variables, stringify objects, etc. all inside a static file
Serverless Guru

24. Serverless Guru
VTL Mapping Template
NO LAMBDA
FUNCTION
REQUIRED

25. “C” in CRUD
Serverless Guru

26. Serverless Guru Source: AppSync Docs
{
"version" : "2017-02-28",
"operation" : "PutItem",
"key" : {
"id" : { "S" : "${context.arguments.id}" }
},
"attributeValues" : {
"author": { "S" : "${context.arguments.author}" }
}
}
Create Request

27. “R” in CRUD
Serverless Guru

28. Serverless Guru Source: AppSync Docs
{
"version" : "2017-02-28",
"operation" : "GetItem",
"key" : {
"id" : { "S" : "${context.arguments.id}" }
}
}
GET by ID Request

29. Serverless Guru Source: AppSync Docs
{
"version" : "2017-02-28",
"operation" : "Scan"
}
GET ALL Basic Request

30. Serverless Guru Source: AppSync Docs
{
"version" : "2017-02-28",
"operation" : "Scan"
#if( ${context.arguments.count} )
,"limit": ${context.arguments.count}
#end
#if( ${context.arguments.nextToken} )
,"nextToken":
"${context.arguments.nextToken}"
#end
}
GET ALL Advanced

31. “U” in CRUD
Serverless Guru

32. Serverless Guru Source: AppSync Docs
{
"version" : "2017-02-28",
"operation" : "UpdateItem",
"key" : {
"id" : { "S" : "${context.arguments.id}" }
},
"update" : {
"expression" : "ADD tags :tags",
"expressionValues" : {
":tags" : { "SS": ["${context.arguments.tag}"]
}
}
}
Update Request

33. “D” in CRUD
Serverless Guru

34. Serverless Guru Source: AppSync Docs
{
"version" : "2017-02-28",
"operation" : "DeleteItem",
"key": {
"id": { "S" : "${context.arguments.id}"}
}
}
DELETE Request

35. API Response
Serverless Guru

36. Serverless Guru Source: AppSync Docs
$utils.toJson($context.result)
Generic Response

37. Interested in learning more?
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38. YouTube
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40. Training Site
Serverless Guru

41. training.serverlessguru.com

42. Medium Publication
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43. medium.com/serverlessguru

44. Podcast
Serverless Guru

45. talkingserverless.io

46. Thank you!

47. Serverless Guru
Q & A
ryanjonesirl
ryanjonesirl