How To Build Your Domain Gateway With OpenAPI
An introduction to the domain gateway pattern and a practical tutorial for building one in Kotlin using OpenAPI code generation.
Blog
Essays, debugging notes, and engineering write-ups on Kotlin, backend systems, architecture, and the tradeoffs behind reliable software.
How to Use OpenAPI to Build a Robust RESTful API
How to adopt a spec-first approach with OpenAPI to design and generate a robust, well-typed REST API using Spring Boot, Kotlin, and Gradle.
Create a Custom Spring Boot App Banner
A fun walkthrough of how to replace the default Spring Boot startup banner with custom text and ASCII art to give your application a personal touch.
How does HashMap work in Java?
A deep dive into the internal mechanics of Java's HashMap, covering the equals/hashCode contract, bucket distribution, and the binary tree optimization introduced in Java 8.
How to Break Your HashMap in Less Than a Minute
A cautionary demonstration of how using mutable objects as HashMap keys silently corrupts lookups, and the simple rule that prevents it.
