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From My HCare (Health Tracking) App(Health Tracking) to a Small Cloud Backend

I previously worked on an Android application called HCare. The idea was related to health tracking, including calorie-related information. It was mainly a mobile application project, but while learning AWS I started thinking about what would happen if I wanted to synchronize user data across devices.

Amit Rathod

I am trying to improve my skills

From local data to cloud data

A simple mobile application might initially look like:
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Android App
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Local Storage
A cloud-connected version could become:
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Android App
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HTTPS API
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AWS Backend
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Database
This introduces several AWS concepts.

One architecture I would explore

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Android App
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API Gateway
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Lambda
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DynamoDB
The application could send information such as:
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{
"userId": "user123",
"date": "2026-09-22",
"calories": 1800
}
The backend would validate the request and store it.

Why DynamoDB?

For this type of simple key-value/document data, DynamoDB is a service I want to learn more about.
A possible table could use:
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Partition key: userId
Sort key: date
That would allow the application to retrieve a user's records by date.

Where Lambda fits

Lambda would allow me to run backend code without maintaining a traditional server.
For example:
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POST /calories
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API Gateway
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Lambda
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DynamoDB
The Lambda function could:
  1. Validate the request
  2. Check the user identity
  3. Prepare the data
  4. Write it to DynamoDB
  5. Return a response

Authentication is important

Because this application deals with personal information, I would not make the API open to anyone.
One AWS service I would explore is Amazon Cognito for user authentication.
The possible flow could become:
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User
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Login
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Cognito
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Token
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API Gateway
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Lambda
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DynamoDB
I am still learning AWS security, so I would treat authentication and authorization as part of the project rather than something to add at the very end.

What I want to learn from this project

This project gives me a practical reason to learn:
  • API Gateway
  • Lambda
  • DynamoDB
  • Cognito
  • IAM
  • CloudWatch
I like this approach because I can take something I already built and gradually turn it into a cloud application instead of learning each AWS service in isolation.
I have not implemented the complete AWS architecture yet. This is the version I would like to build as I continue practicing.
# students# aws-lambda# aws-cloud-development-kit# amazon-dynamodb# beginner-projects
Any opinions in this article are those of the individual author and may not reflect the opinions of AWS.
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