- Start with SaaS Pegasus https://www.saaspegasus.com/
- Deploy to Heroku
- Get comfortable with "X-in-HTML" frameworks - Tailwind, HTMX, Alpine
- Deliver your mobile app as a PWA https://web.dev/what-are-pwas/
Not surprisingly, this is also the stack I'd recommend for a solo developer, though I will also sprinkle in React as it makes sense (not as an SPA / decoupled app, but instead embedded in Django as I describe in the JS guides).
Also, I'm pretty agnostic on CSS. Tailwind is nice but I'd use it with a UIkit (Pegasus uses https://daisyui.com/) or TailwindUI. I also think Bootstrap, Material and Bulma are totally fine options if you aren't interested in laying out everything with your own flexes and grids.
(Nowadays I'd replace Turbo/Stimulus -> HTMX/Alpine)
Special thanks to Cory for his excellent guides on Django + JS: https://www.saaspegasus.com/guides/