Intro

Investalk is a chat app specialized for discussing a stock market in South Korea. Users could join a specific stock channel to share ideas, information, and so on. Also, it gets the latest stock data from the server that aggregates the data using web scrapping.

Responsibility

Mobile Client(Android / iOS)

I developed mobile apps using React Native. They wanted React Native to reduce the cost of the development. Also, they tried to use Sendbird SDK to build the chat feature.

Architecture

I used Redux and Redux-observable to manage the app's states and handle async processes such as a network API call.

Login

I implemented social logins(Facebook, Apple, and Kakao) and email signup.

Profile

I developed the page showing a user's profile such as avatar, user name, email, Etc.

Chat

I implemented chat features using Sendbird SDK. Most features that I implemented were below,

• CRUD a chat room
• Join/Leave a chat room
• Send an image in a chat room
• Send a text message
• Search a chat message
• Push notification for new message
• Show a badge of the number of unread messages
• Mark as read or unread message

Server

I designed the backend architecture and developed the server APIs. I used AWS RDS(Mysql) to manage the user data and the chat rooms synced with Sendbird account because using sequelize.js made the development easy instead of writing a sql query.

User management(Login, Signup)

I developed APIs for user management. I implemented the login/signup APIs using Passport.js. Additionally, I created several APIs for managing users in the administrator website, like banning a user account.

Chat room management

I developed APIs for managing chat rooms. I implemented an API to mark a chat room as a favorite list item in a specific user account.

Crawling data

There was a batch process to crawl the server's data analysis, Retrieval, and Transfer System(DART) from the institute website. Then, I implemented an API to read the crawled data from the database table.

Deployment

The client had already created an AWS account for the deployment. So I used AWS ECS and AWS Batch to deploy the application.