Intermediate profile page for Gerard Klijs

I've been doing Java and Kotlin for most of my career. Doing Clojure and Rust in my free time, and dabbled a bit with Node.js. I have experience with several types of API's. Using REST based on OpenAPI, GraphQL, and async API's based on Kafka in formats like Protobuf and Cloud Events. For BKES I used gRPC. I created and maintain a Rust library to use schema registry schema_registry_converter.

I've presented on using GraphQL with Apache Kafka at GraphQL Summit 2019. I also presented at Kafka Summit 2020 and Kafka Summit 2021, and some others. I'm trying to write more blogs, I've written some at There are also two blogs I wrote in cooperation with Confluent, using Rust with Kafka and using GraphQL with Kafka. There is also one about the background of the Rust library on the Open Web blog page.

You can find me on Twitter and LinkedIn. Currently I'm working for Open Web, as this is mostly a consultancy company, I work for several companies via them, currently for Mendix, a low code platform.

As you might have guessed frontend isn't my strong suit. I do plan to have something more fancy at some time in the future trough. Likely using Bulma just like for the pokequiz I once made.