Writing on performance, systems architecture, and software engineering.https://marcocasanova.deven-UShttps://marcocasanova.dev/en/blog/react-virtual-dom-costhttps://marcocasanova.dev/en/blog/react-virtual-dom-costA practical look at where React spends time, why re-renders get expensive, and when optimisation is worth the complexity.Sun, 12 Apr 2026 00:00:00 GMTReactPerformanceFrontendm.casanova.dev@gmail.comhttps://marcocasanova.dev/en/blog/nodejs-event-loophttps://marcocasanova.dev/en/blog/nodejs-event-loopHow Node.js handles thousands of concurrent connections on a single thread, the phases callbacks actually run in, and the mistakes that stall the whole process.Fri, 20 Feb 2026 00:00:00 GMTNode.jsPerformanceBackendm.casanova.dev@gmail.comhttps://marcocasanova.dev/en/blog/web-security-fundamentalshttps://marcocasanova.dev/en/blog/web-security-fundamentalsThe vulnerability classes that actually cause breaches, why they survive code review, and the structural defences that make them hard to reintroduce.Sat, 08 Nov 2025 00:00:00 GMTSecurityBackendBest Practicesm.casanova.dev@gmail.com