I dunno about in the UK but in the US it would be illegal for companies to discriminate against you based on your stammer, and I know personally I would not car

I dunno about in the UK but in the US it would be illegal for companies to discriminate against you based on your stammer, and I know personally I would not care. I would be fine doing the interview over text if that's more comfortable for you. Don't let them take advantage of you. Of course I would need to see your work to know if they actually are, but if you can write PHP/Ruby and JavaScript they probably are.