Today, AWS Lambda introduces public preview runtimes, a new way to try upcoming language versions on Lambda before their general availability (GA) release. Starting today, you can create and update Lambda functions using Node. 15, the first runtimes available as public previews. Previously, Lambda has always launched new runtimes as Generally Available (GA), giving you a production-ready experience from day one. But this means you couldn’t run your functions on Lambda using a pre-release language version, and we couldn’t hear your feedback while breaking changes were still possible.
Public preview runtimes change that. By putting pre-GA runtimes in your hands months earlier, we can listen to your feedback and address it before GA, while we still have the opportunity to make breaking changes to improve the runtime. Preview runtimes are available in all AWS commercial Regions , AWS GovCloud (US) Regions , and China Regions . They use the same runtime identifier as the eventual GA runtime, so your functions graduate automatically when the runtime reaches GA, with no action required. When Lambda launches a new runtime as GA, that means it is ready for use in production workloads from day one.
Historically, the Lambda team has validated new runtimes through internal testing and pre-release benchmarking. However, without real customer workloads running on the runtime, some issues only surface after the GA launch. And once the runtime is GA, the scope to address those issues is much reduced since we cannot risk breaking existing production workloads. Public preview runtimes address this by opening up a pre-GA feedback window. During this period, you can deploy functions using the upcoming runtime, and the Lambda team can act on what you find, including making potentially breaking changes if necessary.
In addition, because the upstream language is still in its pre-release phase, there’s also the opportunity that issues discovered during preview can be fixed in the runtime itself, not just worked around. This benefits everyone involved. You get a runtime that’s been tested against a broader range of real workloads before it reaches GA. Third-party partners, including observability providers, infrastructure-as-code tools, and deployment frameworks, get time to validate compatibility. And upstream language communities get a signal from a major cloud p