I applied in January and the process took around for 4 months.
The application process consisted of the online application with an upload of your CV. This was followed by online numerical and competency tests. After this, I was invited to a telephone interview which was done by an external company but had good knowledge of Santander.
Following this was the assessment centre where we had to do a Group Exercise, Solo presentation and competency interview with 2 employees at the company. The assessment centre was in Narborough, Leicester. They got back to me within 2 days of the assessment centre.