ELTmallit

ELTmallit is an open-source collection of reusable templates and patterns for building ELT (Extract, Load, Transform) data pipelines. The project provides modular building blocks intended to speed development, improve consistency, and encourage best practices across data integration tasks. Templates cover common scenarios such as batch and streaming sources, data cleansing, schema evolution, and loading into popular data warehouses and data lakes.

The project emerged in the early 2020s from a community of data engineers and architects seeking to standardize ELT patterns. It is maintained by a lightweight governance model with core maintainers and contributor guidelines, and uses a versioned release process to track changes and compatibility.

ELTmallit comprises source connectors, transformation blocks, loading configurations, and metadata templates for lineage and testing. Each template is designed to be adapted to a user's environment and can be combined with a lightweight orchestration layer or run as part of existing pipelines. The project supports common scripting languages such as SQL and Python and targets cloud platforms including Snowflake, BigQuery, Redshift, and Databricks, while also offering on-premises options.

Contributions are accepted via a public repository with issue tracking and pull requests. Users are encouraged to adapt templates, document changes, and share best practices. The project is released under the Apache 2.0 license to encourage reuse and collaboration.

ELTmallit has been adopted by several midsize organizations and data teams seeking a starter kit for ELT pipelines. Proponents cite faster onboarding and better standardization; critics note that templates may require adaptation to complex environments. See also: data pipelines, ELT, data integration.