Yes, APM program is very supportive with mentors and advice
As a large company promotion schedules are very transparent. You start as P30 and can see from day 1 the competencies of P40 (for promotion) as well as P30 (for achieving strong performance reviews/promotions). These are all categorised clearly and you review twice a year with your direct manager. You are also able to participate in professional development opportunities outside of your direct role (i.e I was involved in AI sessions with other designers).