Pros
Some teams/departments have great technology - RBWM Digital, GBM, etc. Some managers are understanding, and easily give WFH. Most colleagues are supportive and approachable, same goes for most managers. Leave system (25-30 privilege and 10 sick, 10 consecutive mandatory) is one of best in industry.
Cons
Low focus on tech (bank-first, tech-company-later approach). Little to no focus on agile and devops. If you begin to work well, you'll get burdened with the work of entire projects on your own. Cumbersome approach for approvals for anything tech-related - ranging from a a few days to a few weeks. Senior management have categorically stated that they will never let go of 'heritage' tech like mainframes - which means most tech of HSBC will be stuck in the 60s. Few aspects like strict dress code, bad cafeteria food and bad seating management on floors needs to be improved quickly.