Depends on where you live, and what non-programming experience/expertise you bring with. Expert-level knowledge is just a small piece of the puzzle. In London,

Depends on where you live, and what non-programming experience/expertise you bring with. Expert-level knowledge is just a small piece of the puzzle. In London, I've recently seen senior engineer salaries range from about £60k at the lower end to about £120k at the upper end. Which is such a wide range as to be totally unhelpful. I'd say it shouldn't be hard to find a range of jobs to apply for at around £85k, which seems to be the most common ballpark figure.