There were couple of video calls with the manager and other SSE. Then a C4 design test. Finally a long interview with another manager and two other engineers. Though the while process took over 4 weeks. Final interview including lengthy technical questions and then they ran through all the benefits and expectations for the role.
After the final interview, had to wait for at least 6 working days to be told that they offered it to someone close to Manchester as maybe they want them to come into the office in Manchester.
I think if the location was a factor, then the SSE role should not be advertised for London. I requested feedback and none so far.