Developing Production-Grade Features for Machine Learning Models

In the ever-evolving landscape of machine learning, feature management has emerged as a key pain point for ML Engineers at Airbnb. While they strive to create innovative models for various products, they often find themselves spending a significant amount of time dealing with infrastructure complexities instead of focusing solely on their models. Airbnb recognized the need for a solution that could streamline feature data management, provide real-time updates, and ensure consistency between training and production environments.

Enter Chronon, a powerful API designed by the Airbnb team to address these challenges head-on. Chronon empowers ML practitioners to define features and centralize data computation for model training and production inference, guaranteeing accuracy and consistency throughout the process.

Ingesting Data from Diverse Sources

Chronon can ingest data from various sources, including event streams, fact/dimension tables in the data warehouse, table snapshots, Change Data Streams, and more. Whether real-time event data or historical snapshots, Chronon handles it all seamlessly.

Transforming Data with Flexibility

With Chronon’s SQL-like transformations and time-based aggregations, ML practitioners have the freedom to process data with ease. Whether standard aggregation or sophisticated windowing techniques, Chronon’s Python API empowers users to perform complex computations while ensuring full flexibility and composability.

Online and Offline Results Generation

Chronon caters to both online and offline data generation requirements. Chronon has you covered for low-latency end-points serving feature data or Hive tables for training data. The “Accuracy” parameter allows users to decide the update frequency, making it suitable for a range of use cases, from real-time updates to daily refreshes.

Understanding Accuracy and Data Sources

Chronon’s unique approach to accuracy enables users to express the desired update frequency for derived data. Whether near real-time or daily intervals, Chronon’s “Temporal” or “Snapshot” accuracy models ensure that computations align with each use-case’s specific requirements.

Data sources are essential components in the Chronon ecosystem. It supports three primary data ingestion patterns:

  • Event data sources for timestamped activity
  • Entity data sources for attribute metadata related to business entities
  • Cumulative Event Sources for tracking historical changes in slowly changing dimensions

Computation Contexts and Types

Chronon operates in two distinct contexts: online and offline. Online computations serve applications with low latency, while offline computations are performed on warehouse datasets using batch jobs. All Chronon definitions fall into three categories: GroupBy for aggregation, Join for combining data from various GroupBy computations, and StagingQuery for custom Spark SQL computations.

Understanding Aggregations for Powerful Insights

Chronon’s GroupBy aggregations provide various extensions to traditional SQL group-by functionalities. Users can leverage Windows for time-bound aggregations, bucketing for additional granularity, and auto-unpack to handle nested data within an array. Additionally, time-based aggregations offer even more flexibility to create insightful features for ML models.

A Seamless Integration for Airbnb’s ML Practitioners

Chronon has proven to be a game-changer for Airbnb’s ML practitioners. Chronon enables users to generate thousands of features to power ML models effortlessly by simplifying feature engineering. This revolutionary solution has freed ML Engineers from the burden of manual pipeline implementation, allowing them to focus on building innovative models that cater to ever-changing user behaviors and product demands.

In conclusion, Chronon has become an indispensable tool in Airbnb’s machine-learning arsenal. Providing a comprehensive feature management solution has elevated the productivity and scalability of feature engineering, empowering ML practitioners to deliver cutting-edge models and enhance the Airbnb experience for millions of users.