AWS Lambda functions have a local temp directory. I have successfully used that in the past to store state. In my application, I had a central worker process

AWS Lambda functions have a local temp directory. I have successfully used that in the past to store state. In my application, I had a central worker process that would ingest state updates and would periodically serialize the data to a MySQL database file, adding indexes and so forth and then uploading a versioned file to S3. My Lambda workers would check for updates to the database, downloading the latest version to the local temp directory if there was not a local copy or if the local copy was out of date. Then the work of checking state was just a database query. You can tune timings etc to whatever your app can tolerate. In my case the problem was fairly easy since state updates only occurred centrally; I could publish and pull updates at my leisure. If I had needed distributed state updates I would have just made the change locally without bumping version, and then send a message (SNS or SQS) to the central state maintainer for commit and let the publication process handle versioning and distribution.