# Lambda runtimes

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/aws-lambda-developer-guide.git)
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## Runtime modifications

* **Note**\
  Invocations may fail if the wrapper script does not successfully start the runtime process.

## Tutorial – Custom runtime

* **Note**\
  On Windows, some Bash CLI commands that you commonly use with Lambda (such as `zip`) are not supported by the operating system's built-in terminals. To get a Windows-integrated version of Ubuntu and Bash, [install the Windows Subsystem for Linux](https://docs.microsoft.com/en-us/windows/wsl/install-win10).
* **Note**\
  Runtimes have additional responsibilities, including error handling, and providing context information to the handler. For details, see [Building a custom runtime](https://github.com/kevinslin/aws-reference-notes/blob/main/services/aws_lambda/runtimes-custom.md#runtimes-custom-build).

## AVX2 vectorization

* **Note**\
  Lambda arm64 uses NEON SIMD architecture and does not support the x86 AVX2 extensions.