I've been in similar position as you, so i feel for you.
I've worked in the USA and Canada for several companies in the past, and also went through several visa procedures (partially). My suggestions is to start an LLC in the UK and contract yourself out to one or multiple (startup) companies. That's what I did. Not only does that evade a lot of visa headache's, and makes it way easier for companies to recruit your services. It also turns you into an entrepreneur, which is a more productive way to live your life ihmo. Who knows you might be hiring people yourself soon.
You have to fly back and forth atleast once every 3 (or 6?) months. But if you're smart you have your client pay for that. (much cheaper then navigating visa-applications)
The only thing to watch out for at the customs is if they ask you what your doing here is that your here for either "sales meetings" or "training of people". Don't say your just working here. and always have a recent, written letter from one of your client-companies on you, inviting you to come help em out with trainings or other interim-solution providing. I've avoided any immigration problems like this for years. Worst thing: they will have you explain it, and then they realize its a grey area and they cant really give you any problems for it.
Not sure if that's good advice. Committing immigration fraud and lying to border officials can get you in serious trouble (18 U.S.C. § 1001). Not only you, but also the company that's paying for your services. It's only a matter of time until a CBP officer starts asking questions about those month-long sales meetings and training sessions.
You have to fly back and forth atleast once every 3 (or 6?) months. But if you're smart you have your client pay for that. (much cheaper then navigating visa-applications) The only thing to watch out for at the customs is if they ask you what your doing here is that your here for either "sales meetings" or "training of people". Don't say your just working here. and always have a recent, written letter from one of your client-companies on you, inviting you to come help em out with trainings or other interim-solution providing. I've avoided any immigration problems like this for years. Worst thing: they will have you explain it, and then they realize its a grey area and they cant really give you any problems for it.