When I started using AWS Lambda my team used the serverless framework to describe our AWS resources. This is easing things a lot compared to writing only plain CloudFormation templates. But still, there was a lot of CloudFormation to be written. This used to be nobody’s favourite task. Then CDK came to the rescue.

The general advantages of CDK

Writing CloudFormation sucks. It is highly repetitive, lengthy, and slow. Code completion is really limited and I just cannot manage to remember the syntax of those intrinsic functions.

So nobody needed to convince me when CDK came along. Finally, there is code completion, extraction of repetitive…


Pull request reviews are an essential tool to improve the quality of the software a team produces. In a team working with or towards continuous deployment it is the last human quality gate on the way to production. And not only that, when done right, pull request reviews are also a great tool for knowledge sharing in a team. So we better get this right. Unfortunately, this is easier said than done.

In this post we will look at some learnings about pull request reviews I collected in my daily work.

You are going too fast

The authors of “Accelerate” propose to measure the deployment…


This post will show how we can use the new native image trace agent to generate GraalVM native image configuration. The agent can track all usages of dynamic features and thus avoids manual configuration for these aspects.

In a previous article about Fighting cold startup issues for your Kotlin Lambda with GraalVM I have shown how we can speed up cold startup of AWS Lambda functions using GraalVM native images and custom AWS Lambda runtimes.

I played around with this a little bit more to see if the approach is also applicable in larger applications. …


In this post we will see how we can tackle high cold startup times for Kotlin functions on AWS Lambda using GraalVM and the AWS custom Lambda Runtimes. Although we use Kotlin here, the article also applies to plain Java.

Kotlin is an awesome language and gains more and more traction. Thus it does not surprise that developers and companies would also like to use this great language in a serverless scenario. AWS Lambda offers a Java11 runtime and it is possible to also run applications written in Kotlin there. …


Spring REST Docs is a great tool to produce documentation for your RESTful services that is accurate and readable. It offers support for AsciiDoc and Markdown. This is great for creating simple HTML-based API documentation that combines hand-written content with generated snippets.

At ePages we have been using Spring REST Docs from the start in our new ecommerce backend. We love its test-driven approach to document a REST API. It helps us to make sure that the documentation is always up-to date. New fields added to a resource are never left undocumented. Changed and removed fields will not leave the…

Mathias Dpunkt

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