I'd hesitate to "go solo" if what you'd like to do is Android + Spring Boot. Because it's a cold, cold world of a race to bottom out there. I have fiverrs doing apps for me for 5$/h and, contrary to what may be a common belief, they are not x10 worse than me. They are almost as good, and once they become fully on par they start asking 15-20$/h - which is insanely low. Only do that on top of some baseline employment that keeps you going.