Is a follow the sun development model realistic for an early stage startup?

A pure follow the sun model, where work is handed off seamlessly between continents, is hard even for large companies. For early stage teams, it only makes sense if the work can be broken into clear, loosely coupled chunks and your process is already mature. If your discovery, design, and decision making are still chaotic, spreading the team across three regions will magnify confusion. A lighter version can work well: use one region for core product decisions and another region for well defined execution work such as implementation, testing, or operations. Aim for fewer, stronger collaboration links rather than constant handoffs between every time zone.