Description

Full-stack currency exchange application that allows users to convert amounts between different currencies. The application includes both frontend and backend components, with a focus on implementing caching for performance optimization.

Backend

• Nest.js
• Redis

Frontend

• Vite/Vue.js 3
• Tailwind CSS

Overview

Backend

Input validation is done via app.useGlobalPipes(new ValidationPipe()). That allows to use Dtos like convert-currency.dto.tsConvertCurrencyDto. Currency exchange rates are taken from Open Exchange Rates API (vendor API). They cache responses hourly. So TTL for internal cache is a diff between next hour and time of initial request. During start of the app available currencies are requested from vendor API and put into cache in tasks.service.ts. Conversion result is rounded to a least second decimal point.

Frontend

Conversion result is updated reactively on currency swap, amount change and on click of Convert button. From UX perspective button is not needed, but it was a feature requirement, so it's present.

Running the app

# start service
$ sh fillK.sh && docker-compose up --build

# closing service
$ docker-compose down

Application should be available by http://localhost:8080