Your front brake discs will be warped, usually it means new discs if it’s bad but can be machined sometimes, it might not be too bad if it’s fine under low load,
I had it on my old golf r and went ahead with new rotors
Hope that helps
Jamie.
If the discs only judder under heavy/high speed braking i doubt there warped as there would also judder under light braking as well.
It can be a uneven brake pad builded up on the disc face which i've had after driving around at low speed a lot,
I found that after braking very very hard from high speed seem to cure it for a short time.
After burning out a set off front ebc reds & boiling the brake fluid at Castle Combe a few years back it never warped the discs,likewise for another forum member who still has the same discs to this day.
Dell.