What we learned from load testing Shopware at scale

Vincenzo Russo's blog post details a comprehensive load testing project on Shopware's PaaS infrastructure to evaluate its performance under real-world e-commerce conditions, using realistic conversion rates, bot traffic, and ERP-driven API imports. The tests spanned seven infrastructure plans, revealing that while Shopware scales predictably with increased resources, performance is heavily dependent on efficient code, caching strategies, and configuration. Shopware handled increased traffic well when infrastructure was adequately tuned, but API activity emerged as a significant cost driver due to its impact on backend load and cache invalidations. The research emphasized that most performance bottlenecks stemmed from code, cache, and configuration issues rather than the platform itself, with caching strategies being critical for maintaining consistent response times. The testing utilized Grafana K6 for simulating traffic and monitored key metrics like p95 Time to First Byte, demonstrating the importance of realistic testing scenarios that mirror genuine storefront behavior.