Ktor 3 vs Spring Boot 3 for Mobile Backends: Coroutine-Native vs Virtual Threads Under Real Production Load

--- title : " Ktor 3 vs Spring Boot 3: Choosing Your Kotlin Mobile Backend" published : true description : " Coroutine-native vs virtual threads compared under production load — cold starts, memory, concurrency patterns, and a decision framework for mobile backends." tags : kotlin, architecture, api, mobile canonical_url : https://blog.mvpfactory.co/ktor-3-vs-spring-boot-3-choosing-your-mobile-backend --- ## What We Are Building Today I want to walk you through a real decision I face on nearly every Kotlin mobile project: **Ktor 3 or Spring Boot 3 for the backend?** By the end of this article, you will have concrete benchmark data, working concurrency examples for both frameworks, and a decision framework you can pull into your next architecture review. This is not a "Framework X is better" post. It is a workshop on understanding what each framework actually gives you under production load so you pick the right one for your team. ## Prerequisites - Familiarity with Kotlin coroutines (