Serverless AQI Prediction System: A Complete MLOps Practice from Feature Engineering to Automated Model Retraining

This project is an end-to-end serverless machine learning pipeline that predicts the Air Quality Index (AQI) for the next 3 days. It integrates GitHub Actions for automatic retraining, Hopsworks feature store, and a production-grade dashboard to address the lag issue in traditional AQI predictions, provide early forecasts for public health protection, and serve as an excellent case study for MLOps practices.

The Air Quality Index (AQI) affects daily decisions (e.g., outdoor activities, health protection), but traditional releases have lag issues. ML-based predictions can forecast several days in advance, but building a production-grade system faces challenges like multi-source data processing, feature engineering, and maintaining model timeliness. This project enables individual developers to deploy enterprise-level prediction services through serverless architecture and MLOps automation workflows.

AQI prediction requires integrating pollutant concentrations (PM2.5, PM10, NO2, ozone, sulfur dioxide, carbon monoxide, etc.) and meteorological data (temperature, humidity, wind speed, air pressure, etc.). The project implements hourly automated feature engineering, including data cleaning, missing value imputation, feature scaling, and time-series feature construction, to ensure the data input to the model is up-to-date and complete.

Air quality data has time-series characteristics; seasonal changes and pollution source variations can affect model performance. The project uses GitHub Actions to implement daily automatic retraining, learning from the latest data to avoid model aging and maintain prediction accuracy.

The project uses Hopsworks feature store to address core ML pain points: feature consistency (same logic for training/inference), feature reuse, feature lineage tracking, time travel (accessing feature states at any historical time point), decoupling training and inference, and improving system maintainability.

Serverless architecture offers three major benefits: cost optimization (billed by actual computing time, suitable for event-driven scenarios), automatic scaling (auto-scales when traffic surges), and simplified operations (no need to manage servers, focus on business logic).

The project provides an intuitive dashboard with real-time AQI values, next 3-day trends, pollutant breakdowns, and health advice prompts, transforming complex prediction results into user-friendly visualizations to support public health decisions.

This project is an excellent MLOps case study that demonstrates the transition from lab prototype to production system. Reusable practices include automation-first, feature as code, monitoring and observability (recommended), and progressive deployment. The architecture is general-purpose and can be extended to prediction scenarios like pollen concentration and UV index, making it an excellent reference for MLOps learners.