Dataform is an open-source CLI tool and core library for defining, compiling, and executing SQL-based data transformations on Google BigQuery. It provides a declarative DSL (SQLX files, YAML configs, JavaScript API) to model tables, views, incremental tables, operations, assertions, declarations, notebooks, and property graphs. The system compiles user definitions into a protobuf-based compiled graph, then executes BigQuery jobs with support for incremental strategies, schema changes, and data quality assertions. It also emits OpenLineage lineage events to Google Cloud's Data Lineage API for governance. The architecture is a CLI application with a core compilation engine, a BigQuery adapter, and a Just-in-Time (JiT) compilation mode for dynamic SQL generation. Key entry points include the CLI commands (`dataform compile`, `dataform run`, `dataform init`, etc.) and the programmatic API from `@dataform/core`. The data flow is: user writes definitions → compilation produces a graph → execution runs BigQuery jobs → lineage events are emitted. External dependencies include Google Cloud BigQuery, protobufjs, yargs, and various Node.js libraries. The codebase is well-structured with clear separation between CLI, core, common utilities, and testing infrastructure. It demonstrates strong engineering practices such as protobuf-based data contracts, sandboxed JavaScript execution via VmRunner, and a comprehensive test suite including integration tests against real BigQuery. However, it carries some technical debt from legacy API compatibility and a complex Bazel build system.