Importance of NodeJS 22 & Python 3.13 Runtimes on AWS Lambda
I'm excited about the AWS “pre:Invent” 2024 announcements of NodeJS 22 & Python 3.13 runtimes being supported on AWS Lambda.
Not because of any language features these new versions introduce.
Instead my excitement is because of the timely introduction of these new runtime versions finally truly show the commitment from AWS to follow the latest long-term supported (LTS) language versions.
Here's some data about the history of NodeJS major releases, their Active LTS start dates, and the dates AWS Lambda started supporting each version:
| Version | Release | Active LTS | Lambda support | Days between LTS vs Lambda |
|---|---|---|---|---|
| 12 | 2019-04-23 | 2019-10-21 | 2019-11-18 | 28 |
| 14 | 2020-04-21 | 2020-10-27 | 2021-02-03 | 99 |
| 16 | 2021-04-20 | 2021-10-26 | 2022-05-12 | 198 |
| 18 | 2022-04-19 | 2022-10-25 | 2022-11-18 | 24 |
| 20 | 2023-04-18 | 2023-10-24 | 2023-11-15 | 22 |
| 22 | 2024-04-23 | 2024-10-29 | 2024-11-21 | 23 |
As you see, with NodeJS version 14 and especially with version 16, AWS was taking a long time to support the latest LTS version on Lambda. They probably had very good reasons for this, but many AWS Lambda users – myself included – felt frustrated. And even today many users have this assumption that it will take a lot of time for AWS to support the latest LTS versions.
I don't remember exactly, but I think during early 2023 I heard some unofficial communication that AWS wants to “commit” (in quotes, because the release schedule is always “subject to change”) to supporting the latest LTS versions and defining a speculative target launch month for each new upcoming LTS version.
Finally, on November 2023, after NodeJS 20 support for Lambda was announced, they updated the documentation to include "Future runtime launch dates" -section; And already back then it stated that for example NodeJS 22 and Python 3.13 should be supported in November 2024.
At the time of writing this, we are living that future: During this 2024 pre:Invent season, AWS did announce those new Lambda runtime versions. Additionally, they updated the documentation about the future runtime versions with new target dates, including NodeJS 24 (targeted for November 2025) and Python 3.14 (targeted for November 2025).
As a heavy user of NodeJS & AWS Lambda, I'm happy about this predictability: I can now plan my projects in such a way that I can follow the NodeJS release schedule and about one month after a new major NodeJS version has become Active LTS, I can start migrating my Lambda code into that new LTS version.
And for the AWS CDK users, there is already a support for this since v2.168.0:
runtime: lambda.Runtime.NODEJS_22_X,