Over the past two decades, CubeSats have emerged as a viable and competitive alternative for accessing space, compared to classical, monolithic satellite designs. Initially conceived as relatively affordable way for universities to access space, mainly for academic and research objectives, CubeSats have shown growing potential as versatile platforms for various purposes, such as Earth observation and in-orbit technology demonstration. Their relatively low cost and fast time of delivery have attracted the interest of not only universities, but also governmental agencies and commercial companies. Over time, it became clear that it was neither efficient nor effective to treat CubeSats as "scaled down" version of larger satellites: instead, tailored methodologies for satellite design and verification were developed, often preferring agile and less restrictive solutions over traditional document-heavy approaches.