There were two interviews, on separate occasions – initially, one with the line manager for the role, followed by a panel interview with two people from within the wider team.
The first interview was a straightforward run-through of the role, my background, combined with a proof-reading test and a couple of technical questions relating to the role. This was quite informal, on the whole.
After that, I received a phone call asking me to attend a second interview a couple of days later. This was a competency-based interview – with even the interviewers apologising for the highly structured nature of it. (Although to be fair, the logic behind it is that everyone gets asked the same questions, and the person in HR did provide a significant amount of information about how to prepare for it in advance of the interview).
Both of these lasted for about 45 minutes, in the office in Canary Wharf. Later on during the same day of the second interview, I was called by the recruiter offering me the job, and accepted.
The background checks for working at Barclays are pretty onerous, and require sending a lot of documents (exam certificates, proof of address, etc) to back up what you've said.
For example: a colleague was left very stressed when they were effectively accused of lying, after HR misunderstood the documentary evidence provided for an academic qualification. The line manager had to intervene to point out that it tallied with what had been stated on the CV. Not exactly a great introduction to the company.