There's various levels of interview, about four in total including an online assessment, telephone interview, an assessment centre day and finally a panel interview. Make sure to research the company a lot prior to all interview stages. Also brush up on your mathematics, spelling and grammar if you've neglected them as they will be tested during the assessment centre stage.

I applied through the employer's website, and then got phone screening interview, which lasts about 10 to 15 minutes and it was quite straight forward. Just asked a few basic questions. Then I was invited to assessment centre, which lasts around 4 hours.