I know that recruitment within TOCs is a hot topic and often a source of frustration for some.
I’m sure Northern, much like other TOCs received hundreds and hundreds of applications for each role. Each application will need to be reviewed and read by a member of the team.
And often there are multiple roles and vacancies being recruited for, all at different stages. I can imagine that they are often exceptionally busy and working hard to process all applications, manage their vacancies, organise assessments, psychometrics and medicals, onboarding new starters and communicating with any candidates in a talent pool/queries from applicants.
Unfortunately, it can take time and patience is a must in Railway Recruitment! There’s no harm if you’re worried in dropping their HR team an email to ask for an update - but don’t fret it can take up to 6 months I believe for some vacancies to be fully reviewed.
And in regards to the person you know being rejected fairly quickly - this was probably an initial review of applications based on things such as location to reject any candidates who don’t meet the safety critical requirements.