Lambda: Failed to create layer version: Unzipped size must be smaller than 262144000 bytes

I'd check that all the dependencies included in the zip file are required and if not exclude what can be removed. Like you can remove node_modules in NodeJs or venv in Python.

The alternative solutions depend on the use case, for instance how often is your Lambda invoked? if it's invoked once per day or such, you can eventually load the dependencies from S3 on start. You can also mount an EFS network share to your lambda [2]

A container image is a good solution for this and you can create an image up to 10Gb. The documentation describes the steps to follow to get started [2].

[1] https://aws.amazon.com/blogs/compute/using-amazon-efs-for-aws-lambda-in-your-serverless-applications/ [2] https://docs.aws.amazon.com/lambda/latest/dg/images-create.html