Hi @johannesweiss,
I was disappointed too... we all want to win 
the language challenge.
I added an enhancement request on the Swift-Sprinter repository Evaluate internal WARM performance of LambdaSwiftSprinterNioPlugin with HelloWorld 路 Issue #38 路 swift-sprinter/aws-lambda-swift-sprinter 路 GitHub .
I'll add consideration there to avoid noise on the forum. Happy if you can take a look to it and if you can give some suggestion on how to evaluate internal performances.
I added the code in the issue so it can be easy to follow.
Principal suspects we need to investigate more:
- In the Go example, the lambda doesn't pass the Data and Context buffer
- Some evaluation/instance of the Data/Context could be improved in Swift
- AsyncHTTPClient performance could be improved