It's not clear if you're asking about solo developer or "solo company" as it were. Anyway, typically if you're doing a startup the advice is to get a partner.

It's not clear if you're asking about solo developer or "solo company" as it were. Anyway, typically if you're doing a startup the advice is to get a partner. Then maybe you're not so solo anymore. If that's not possible, then expect to spend lotsa time on marketing instead of coding :)