Customer API Demo

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The project demonstrates a customer experience API with the resources which allows the following.

HTTP Method	Resource Function
GET	List All customer records
GET	Get record by first Name
POST	Create a new customer
PUT	Update a customer
DELETE	Deletes a customer

Use cases and commentary

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1. A consumer may periodically (every 5 minutes) consume the API to enable it (the consumer) to maintain a copy of the provider API's customers (the API represents the system of record)

   As part of this use case the API has to carry only last updated records from the provider to client . Loading of full records all the time for every 5 minutes will kill the memory and data over the network will be high. To avoid this we need to get the last updated range of records from a given time to current time . This is provided as a query parameter for the get all customer records call.

2. A mobile application used by customer service representatives that uses the API to retrieve and update the customers details

   The resource for getting the customer record by first name for retrieval and update is defined in RAML as part of this API. The retrieve record can be cached for lowering the latency with minimal cache expiration time . The resource will not be using any payload instead as per REST principle uri param with first name of the customer is used as the key. Also the since the API is meant for a mobile application the resource has to be secured with OAuth 2.0 implicit grant type . The current implementation submitted does not cover this security set up in proxy as this is ideally part of API manager policy

3. Simple extension of the API to support future resources such as orders and products

   Orders and Products resources are desinged as seperate raml file and included as part of the parent api.raml this allows to extend the resources independetly . RAML extension\overlay feature can also be leveraged for the same since the use case is limited to one category of resource extension core is not implemented

Implementation Design

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As part of the implementation , I have treated the API as an experince API . Based on the mulesoft API 3 tier design the experience API can interact with Process API which in turn can connect with System API or the experience API can directly interact with system API. For demonstration purpose the experience API is going to interact with customer backend service layer which connects with Derby database for all CRUD operation on the cutomer record.

Note: The experience API is not set with auto-discovery element to act like a proxy

Pre-requisites for Demo

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Download the customer experience API flow

https://s3-ap-southeast-2.amazonaws.com/mule-delbucket/exp-customer-api.zip

Download the customer backend service flow

https://s3-ap-southeast-2.amazonaws.com/mule-delbucket/CustomerBackendService.zip)

Download postman collection to test the service

https://s3-ap-southeast-2.amazonaws.com/mule-delbucket/CustomerExperienceAPI.postman_collection.json

Running the Demo

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1. Import the downloaded customer experience api and customer backend service in anypoint studio
2. Once imported right click the exp-customer-api project and select mule run with maven configuration
3. On the General tab select the customer-service project check box
4. click Apply
5. Click Run
6. Once both the application are deployed open the downloaded postman collection.
7. Click on the POST method to create your first cutomer record.