If by "big consultancy" you mean working for one of the big 4 consulting firms this seems to me to be the worst possible combination for OP. I've worked with a ton of these types and my impression of them only seems to decline with each interaction. The "expertise" of big four consultants that I've met is largely around sounding good rather than honestly understanding technical solutions. The are optimized for delivering solutions rather than solving problems. So the work is going to be far more tedious and empty that working in big tech. The pay is also pretty bad for something that is supposed to be "high paying". I very valuable role at a startup or small company can easily get you more money with a lot more fun.