Experimental Rust-Based Parallel Indexer Ships—10x Faster IntelliSense

Microsoft has released an experimental update for the Python extension in Visual Studio Code (March 2026) that promises a dramatic speedup in code indexing. The new parallel indexer, written in Rust and running out-of-process, delivers an average 10× performance improvement on large Python projects.

“Early tests show completions and auto-imports become near-instant after workspace open, even on codebases with hundreds of thousands of lines,” said a spokesperson for the Visual Studio Code Python team. “We’re rolling this out as opt-in to gather feedback from a wide range of environments before making it the default.”

The feature is controlled by the setting Python › Analysis: Enable Parallel Indexing. To try it, users can open Settings, search for “Parallel Indexing,” and enable the checkbox. After reloading VS Code, the new indexer activates. The team notes the impact is most noticeable on larger projects.

Search Python Symbols in Installed Packages—No More Alt-Tabbing to Docs

Another major addition is the ability to find symbols from third-party packages installed in the active virtual environment. Pylance now includes these symbols in the Workspace Symbol search (Cmd/Ctrl+T), letting developers locate functions or classes inside libraries without leaving the editor.

“This is huge for exploring unfamiliar codebases or libraries like NumPy,” commented a senior open-source contributor familiar with the release. “You no longer need to jump to external documentation just to see where a method is defined.”

The feature is opt-in via the setting Python › Analysis: Include Venv In Workspace Symbols. When enabled, symbols from site-packages appear in search results. For libraries lacking a py.typed file, only symbols exported via __init__.py or __all__ are shown to keep results focused. Developers can fine-tune indexing depth per package using the Python › Analysis: Package Index Depths setting.

Background: Continuous Evolution of Python Tooling in VS Code

The Python extension for Visual Studio Code, powered by the Pylance language server, has become a cornerstone for Python developers. The March 2026 release builds on years of work to improve IntelliSense performance and code navigation. The existing indexer, written in Python and TypeScript, had been a bottleneck on large projects.

“Rust was chosen for the new indexer because of its memory safety and raw speed,” explained a Microsoft engineer. “Offloading indexing to a separate process keeps the UI responsive even while parsing thousands of files.” The team has been testing the parallel indexer internally, and early results confirm a consistent 10× speedup across a variety of project structures.

The symbol search enhancement addresses a common pain point: locating definitions inside installed packages. Previously, workspace symbol search only covered files within the project folder. Now, developers can navigate into third-party libraries seamlessly.

What This Means: A More Productive Python Development Workflow

For developers working on large monorepos or data science projects with many dependencies, the parallel indexer could shave minutes off the initial indexing time. Combined with the new symbol search, the extension shifts from a plain editor to a more powerful IDE-like experience.

The experimental nature of the indexer means users should expect occasional instability, but the feedback loop is designed to refine the feature for a future stable release. “We encourage all developers, especially those with large codebases, to enable it and report issues,” said the Microsoft spokesperson. “Your feedback shapes the final product.”

To get started, visit the Python extension page and ensure you have the latest update. Check the release changelog for a full list of improvements, including minor bug fixes and performance tweaks.