Increment versions in smaller upgrades. Make sure you can run unit tests, end to end tests, and QA on each new version. Also, make sure to read the NodeJS change log to know what APIs change and how they may affect your app. You’ll need to do searches across you codebase to find affected areas.

As you patch this code, ensure your CI process also gets updated since you’ll need to download a new version of Node on your staging/production servers. Tests these as well.

If possible, make a clone of your production database and create a mock production environment. Run requests against this environment. This will give you the best feedback as to whether crashes may occur.

Ensure you can deploy to production in a way that can easily be rolled back. Also, you’ll want to have the right monitoring / logging in place to know when a request crashes your app and how you can reproduce it.