With the explosion of consumer devices, designing flexible and device-independent optimized APIs has become increasingly challenging. This talk covers API design best practices and core principles for microservice and serverless architecture, demonstrates them using a custom PHP framework, and summarizes the lessons learnt. Additionally, the talk covers highly optimized API design using graphQL to address versioning issues and device resource constraints. Lastly, we cover key takeaways for implementing and migrating to these architectures.

1. 1 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Device Independent API Design
PRESENTED BY: AMRITA JAIN
DIRECTOR, DIGITAL TECHNOLOGIES, BEACHBODY, LLC.
MICROSERVICES+GRAPHQL+SERVERLESS

2. 2 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Agenda
Mission Statement
Milestone1: Microservices
Milestone2: GraphQL
Milestone3: Serverless
Key Takeaways
Q & A

3. 3 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Journey so far..
1990s and earlier 2000s 2014s 2017s
Monolithic
Tight coupling
Traditional SOA
Loosely coupled
Microservices
Decoupled
Serverless
Cheap decoupling

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Evolution of clients/consumption

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Evolution of APIs/ Role of APIs
https://www.blog.vba-market.com/2016/10/19/10-useful-real-world-api-examples/

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0
2
4
6
8
10
12
14
16
18
20
Monolithic BE+FE Microservices Serverless
Platforms Subscribers Team size
Journey I took at Beachbody
Evolution of API
architecture with the
growth in
1. Platforms (1 to 6)
2. Subscribers
(200K to > 1.5M)
3. Team size (1 to 20)
* Units in 100K
2014 2015 2016 2018

7. 7 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Design APIs that
scales with traffic, platforms, team size
and
minimizes cost in terms of dollars, personnel and latency.
Mission Statement

8. 8 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
“
”
Unix Philosophy
Write programs that
do one thing
and
do it well.
Write programs to
work together.
Peter H. Salus
Milestone:
Microservices

9. 9 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
•Independently managed, clearly defined
services.
•Each microservice owns its data-source.
•Better scaling, failover and recovery.
•Flexibility in choice of language and
deliverables.
Microservices: Benefits

10. 10 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
•Redundant code for common
functionality.
•Inconsistency in common behaviors.
•Harder for clients developers
•Service Discovery
•Data aggregation.
•Performance and bandwidth
constraints.
•Automation, CI/CD is non negotiable.
Microservices: Challenges

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Best practices: Get ahead of Heterogeneity
Convention over configuration
• Develop and adopt standards and
conventions
• Agree/Disagree but commit
• Reduce decision-making for common
trivial problems

12. 12 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Best practices: Get ahead of Heterogeneity
Custom MicroService Framework for PHP
• Enforces same code flow for all
MicroServices
• Consistent error handling and response
codes
• Circuit Breaker Failover Handling
• Provides utilities such as database, search
engine, cache wrappers
• Unifies security practices

13. 13 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Best practices: Service Discovery
API Gateway
• Route to proper microservice
• Rate Limiting
• Tracing + Debugging + Monitoring
• Caching + Invalidations
My address ?

14. 14 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Best Practice: Monitoring
System-level monitoring
◦ CPU, Memory, I/O etc.
◦ StatsD, Graphite
Application-level monitoring
◦ Exceptions, error logs
APM
◦ Performance Issues & Bottlenecks
Dashboards
◦ Graphana
Which service caused failure?

15. 15 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
“
”
Evolving
APIs
without
versions
one vertex
at a time
Lee Byron
Milestone:
GraphQL

16. 16 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Device specific data
• iTunes id, google account id etc.
• Device-specific features eg. showing
promo banner only on Android
• Device specific images
Response Parity

17. 17 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
{ "images": {
"badgeBoxArt": {},
"largeBoxArt": {},
"heroImageTablet": {},
"popularProgramMedium": {},
"devicesBannerImage": {},
"devicesStvBoxArt": {},
"devicesChromecast": {},
"devicesParallaxImage": {},
"devicesTabletHomepageLandscape1x": {},
"devicesTabletHomepageLandscape2x": {},
"devicesTabletProgramLandscape2x": {},
"devicesTabletProgramPortrait2x": {},
"devicesGlobalImage": {}
}}
Response Parity : Example

18. 18 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Performance tradeoffs
• Clients that can parallelize prefer many calls
smalls
• Other clients prefer minimal data in one call.
Bandwidth constraints
• Prefers minimal data in one go.
• Offline downloads, support batch
Performance and Bandwidth

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• Always have to support all versions until
all users have upgraded their apps.
• Tedious & Expensive
• Developer Time (∝ O(versions))
• Error Prone (∝ O(versions))
• Testing time (∝ O(versions ×
platforms x
platformVersion))
API versioning

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GraphQL: In Action

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GraphQL: In Action

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ü Root node and think of data as graph.
ü Implement Graphql schema.
ü Define Query types: field on the query is processed
ü Map the underlying API/Data
ü Data manipulation can be done via resolvers
ü Need help?
ü Slack
ü User Groups
Implementation Tips

23. 23 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Implementation Tips
Ref: https://github.com/webonyx/graphql-php/blob/master/examples/00-hello-world/graphql.php
curl http://localhost:8080 -d
'{"query": "query { echo(message: "Hello World") }" }'

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Implementation Tips
Ref: https://github.com/webonyx/graphql-php/blob/master/examples/00-hello-world/graphql.php
curl http://localhost:8080 -d
'{"query": "query { echo(message: "Hello World") }" }'
{"data": {"echo": "You said Hello World" }}

25. 25 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Best practices: Start Small
Incremental Adoption
• Start with one client
• Start with APIs with more content-
based data
Image ref:https://www.youtube.com/watch?v=WQLzZf34FJ8

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Best practices: KISS Principle
Thin Interface
• No extra business logic, framework
stuff.
• Depth and amount limiting
• Query cost analysis and checks.
1 Request

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Adding an extra layer and keeping it updated.
Workarounds:
• Apollo Graphql libs
• Dynamic schema based on Swagger:
https://github.com/amritajain/swagger-graphene
• Start here: https://github.com/chentsulin/awesome-graphql
Caveat: Extra Layer

28. 28 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
“
”
Perfection
is achieved not when
there is nothing
more to add,
but
when there is
nothing left
to take away
Antoine de Saint-Exupery
Milestone:
Serverless

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Serverless Benefits
No Servers to
provision or
manage
Only pay what
you use for
Standardization
and ease of
deployments
Event driven
Scaling, built-in
availability and
fault tolerance

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• Auto-scaling Websites and APIs
• Serving up static content
• Image and Video Manipulation
• Event streaming
• ETLs, Time-based batched jobs
• 30 serverless architectures in 30 minutes
Serverless: In Action

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Serverless: Sample yaml file

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Serverless: Sample yaml file
serverless deploy --accountID <AWS::AccountId>
--stage <dev|qa|prod>
--deploymentBucket <bucketName>

33. 33 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Serverless: Sample yaml file

34. 34 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Serverless: Sample yaml file
serverless deploy --accountID <AWS::AccountId>
--stage <dev|qa|prod>
--deploymentBucket <bucketName>

35. 35 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
• Avoid fat/monolithic functions
• Optimize for language of choice
• Cloud agnostic frameworks
• Logging: Log-levels, capture device names, OS versions, and types in request
headers
• Store all environment variables separately and keep them encrypted.
Best Practices

36. 36 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
• Cold starts
• Invariable Demand
• Local setups: 3rd-party libs that can help
Common Pitfalls

37. 37 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
“
”
Nothing good
comes easy
because
nothing easy
does any good.
Unknown
Best Practices
& Learnings

38. 38 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
• Follow microservice principle: One microservice, One repo, One datasource.
• Clear lines of ownership
• Core framework: injected via composer
• Git Flow
• Dev prod parity
Learning: Codebase

39. 39 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Learning: Development Processes
Integrated into CI process
• Unittests
• Integrated with Travis
• Integration tests
• All microservice collections include
Postman tests
• Used by devs to for quick validation.
• Used by clients for parallel implementation

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• Swagger
• Provide swagger documentation for every API
• Baked into the framework
• Lucidcharts
• Sequence/Architecture diagrams in Lucidcharts.
• Confluence Documentation
• Must for handoff and demo.
Learning: Development Processes

41. 41 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
§ Setup patterns and standards on Day1.
§ Things change: what may seem right today might not be tomorrow, be ready
to evolve.
§ Think of APIs as a product and make it a complete package.
Key Takeaways

42. 42 DEVICE INDEPENDENT API DESIGN BY AMRITA JAIN
Thank you!
@amritajain973
https://joind.in/talk/a578f
Currently @ Twitch!