Usually in these situations I switch the junior developer to the back end which often increases velocity by 20%. Then let one of the senior devs take a brief va

Usually in these situations I switch the junior developer to the back end which often increases velocity by 20%. Then let one of the senior devs take a brief vacation since they can be having issues at home. Usually by the time they are back, everything flows smoothly, velocity doubles and clients are pleased. I believe this approach can be tweaked to work even when the back end is done in .NET.