Breaking: Pylance Gets 10× Faster Indexing with Rust
Microsoft has released an experimental Rust-based parallel indexer for the Python extension in Visual Studio Code, claiming a 10× performance boost on large projects. The new indexer powers completions, auto-imports, and workspace symbol search by running out-of-process.
"In our testing, this indexer is on average 10× faster on large Python projects," said a Microsoft spokesperson. "That means faster completions after workspace open and a more responsive IntelliSense experience."
The update also introduces a opt-in feature to search Python symbols in installed packages, allowing developers to locate functions and classes from third‑party libraries without leaving the editor.
Experimental: Rust-Based Parallel Indexer
The indexer—the engine behind IntelliSense—has been re‑implemented in Rust and runs in a separate process. To enable it, go to Settings, search for "Parallel Indexing", and check Enable Parallel Indexing (Experimental) under Python › Analysis.
"python.analysis.enableParallelIndexing": trueAfter enabling, reload VS Code (Cmd/Ctrl+Shift+P → Reload Window) to ensure the new indexer starts cleanly. Microsoft notes that the impact is greatest on larger codebases; smaller projects may see little difference.
Search Symbols in Installed Packages
A new setting Python › Analysis: Include Venv In Workspace Symbols adds symbols from packages in your active virtual environment to Workspace Symbol search (Cmd/Ctrl+T). This lets you navigate into third‑party libraries directly from VS Code.
"For libraries without py.typed, only symbols exported via __init__.py or __all__ are included, keeping results focused," the spokesperson explained. To fine‑tune indexing depth per package, use the Python › Analysis: Package Index Depths setting.
Because indexing installed packages can affect performance, this feature is opt‑in by design. It gives richer code exploration when needed without changing the default experience.
Background
The Python extension for VS Code, maintained by Microsoft, is one of the most popular language tools on the platform. The March 2026 release continues a trend of performance improvements, following earlier work on Pylance’s language server.
Indexing speed has been a long‑standing pain point for developers working on large monorepos or data science projects. The Rust rewrite addresses this by leveraging a compiled language and out‑of‑process execution.
What This Means
For Python developers, this update promises significantly faster IntelliSense—especially on large projects where indexing could previously cause noticeable delays. The experimental nature means users can test the speed gains early while providing feedback.
The symbol search in packages reduces context switching; developers no longer need to open separate documentation or file explorers for third‑party libraries. This could streamline workflows in data science, web development, and backend engineering.
Both features are controlled through individual settings, giving developers flexibility. Microsoft is actively seeking feedback via GitHub before making the parallel indexer the default.