Nothing reveals the shocking cost of building a custom smartphone OS

Ever wondered what it takes to build a custom operating system from scratch? In its latest collaboration with YouTuber MrWhoseTheBoss, Nothing takes a closer look at what it truly costs to build a new operating system from the ground up. The video, which aimed to create a custom OS for Arun Maini, breaks down every stage of the process, from planning to deployment, and reveals that developing a fully functional mobile OS would cost an eye-watering $40.47 million. As the video highlights, that figure is even higher than the estimated $26 million it would take to produce the hardware of a flagship phone, as shown in the duo’s earlier Dream Phone project.

The video makes it clear that building an OS goes far beyond coding a few apps or designing a slick interface. It begins with planning, a two-month phase during which senior teams outline requirements, budgets, and design goals. From core layouts to smaller visual touches like glowing notifications, every detail is mapped out here. Next comes platform development, a roughly six-month process that involves forking AOSP and building a customized baseline OS.

This is followed by testing, quality assurance and compliance, another six months dedicated to automated checks and internal user trials to ensure everything works securely and reliably. After that, the focus moves to hardware implementation, a three-month period where engineers install and fine-tune the software for specific devices. Finally, deployment and launch bring everything together, adding final polish, pre-installed apps, and the all-important day-one update before rollout.

Each stage carries a hefty price tag. Engineering and design alone make up over $34 million, with another few hundred thousand going toward cloud GPUs, user testing, and R&D tooling. Even essentials such as licenses, testing equipment, and quality assurance add up quickly. Include a 15% contingency for unexpected costs, and Nothing’s total estimate climbs beyond $40 million.

The video also explains why Nothing has opted for a full-fledged operating system project rather than a simple custom launcher. A launcher only changes what the user sees, such as icons, widgets, and layouts, but it doesn’t alter the system framework that manages performance and hardware. An OS, by contrast, defines how everything from memory to sensors and connectivity functions in unison. That’s why Nothing, despite its ambitions, builds its platform on AOSP (Android Open Source Project) instead of starting from scratch. As the company notes, creating a completely new OS, like HUAWEI did with HarmonyOS, could take four years or more and multiply the cost several times over.

The video’s takeaway is clear: hardware might get the spotlight, but software quietly dominates the budget. And when the total hits $40 million, it’s a reminder that innovation never comes cheap.