Arjen Poutsma
Senior Staff Engineer
Arjen is an experienced software engineer with talent and passion for designing simple, yet powerful programming interfaces.
For nearly 20 years, he was a key contributor to the Spring Framework, where he played a vital role in conceiving and developing features such as @Controller, functional web endpoints, and Spring’s suite of HTTP clients—including RestTemplate, WebClient, and RestClient.
Today, Arjen leverages his deep expertise to help organizations improve the design, development and growth of their APIs, and help navigate the open-source ecosystem. He also specializes in reducing code complexity, offering pragmatic guidance to teams aiming for more maintainable and efficient software.
Upcoming conference sessions featuring Arjen Poutsma
A Long Spring: 19 Years of Living with Your Past Mistakes
How do you evolve a framework over nearly two decades without losing the trust of millions of developers? In this talk, I will reflect on 19 years of working on Spring, the Java application framework—from the early days of XML configuration, through the rise of annotations, to the advent of functional programming.
I will share the lessons that come not just from designing APIs and writing code, but from practicing open source stewardship over time. That includes how to innovate under constraints, how to evolve APIs responsibly, how to serve a growing community, and why empathy and restraint are essentials skills when it comes to maintaining open source.
This talk is for anyone willing to learn from my past mistakes, so they can make entirely new ones.
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