This article explains constructing an ETL pipeline in TypeScript for fetching weather data from OpenWeatherMap API and COVID-19 statistics from GitHub, transforming them, and loading into a PostgreSQL database using Prisma.
TypeScript provides static typing and async/await for clearer API interactions and error handling, minimizing runtime errors from external data inconsistencies compared to dynamically typed languages like Python.
The project setup involves configuring a Node.js project with TypeScript, installing necessary libraries for HTTP requests, scheduling, CSV parsing, and database interactions using npm.
The extraction phase fetches data from APIs and CSV, ensuring type-safe results through interfaces and runtime validations, leveraging TypeScript's async/await model for consistent and readable asynchronous code.
Data transformation ensures a coherent schema before database loading, utilizing TypeScript interfaces and runtime validations to catch API data changes early in the process.
Loading data into PostgreSQL with Prisma involves defining database schema, generating Prisma client, and executing type-safe database operations for secure data insertion.
Testing the ETL pipeline involves setting up a PostgreSQL instance, configuring environment variables, running migrations, and orchestrating the ETL process to verify correct data loading and retrieval.
Automating the ETL pipeline with TypeScript entails using node-cron to schedule task execution periodically, integrating extraction, transformation, and loading steps into a scheduled job for automated data processing.
TypeScript's benefits over Python for ETL pipelines include static type checking, streamlined data transformation, consistent development environment, and cleaner async/await model, resulting in a more maintainable and reliable pipeline.
The article serves as a proof of concept for utilizing TypeScript in ETL pipelines, offering a unified stack and reduced debugging overhead compared to Python-based workflows.