Work In Progress

AWS Lambda + DynamoDB + Kotlin codebase containing real world examples (CRUD, auth, advanced patterns, etc) that adheres to the RealWorld spec and API.

Demo

This codebase was created to demonstrate a fully fledged fullstack application built with AWS Lambda + DynamoDB + Kotlin including CRUD operations, authentication, routing, pagination, and more.

We've gone to great lengths to adhere to the AWS Lambda + DynamoDB + Kotlin community styleguides & best practices.

For more information on how to this works with other frontends/backends, head over to the RealWorld repo.

Getting started

Prerequisite

Install Kotlin, Node.js, Serverless CLI
In angularjs-realworld-example-app, run npm install

Build and deploy backend

In the root directory of this project:

./gradlew build
sls deploy

Build and serve frontend

In angularjs-realworld-example-app:

npx gulp

How it works

Routes and their handlers are defined in serverless.yml.

For example, the following section means POST /users is handled by com.serverless.route.usersPost.Handler.

  users-post:
    handler: com.serverless.route.usersPost.Handler
    events:
      - http:
          path: users
          method: post
          cors: true

Design choices

Scrypt-based password hashing
Input validation
Data consistency with DynamoDB transactions

These tradeoffs were made for simpler code:

Hardcoded Scrypt secret. Downside: tokens can't be invalidated
Shared states (like DB and RNG) are singletons, no dependency injections used. Downside: lifecycles of shared states are not controllable. Potential memory leak. Unit-test-unfriendly
Usernames are not changeable
Usernames are case-sensitive
Performance bottleneck in global secondary indices with a single hash-key value, like ArticleTable.CreatedAt and TagTable.ArticleCount
Performance bottleneck in fan-in-based article feed aggregation

chrisxue815/realworld-aws-lambda-dynamodb-kotlin