I've done IBM's final round twice as a candidate (different eras) and I know a few managers there from my network. Here's what the IBM onsite or final loop looks like now.
Format: Most senior and staff SWE roles run a 'virtual panel' these days. Four to five rounds on the same day or split across two days, depending on team. Typical breakdown: One coding / technical round One system design round Two to three behavioral rounds Sometimes a 'manager fit' conversation with the hiring manager
The behavioral rounds are not a formality. IBM has gone deep on what they call 'Essential Behaviors' and the interviewers are often trained to score them systematically. STAR format is expected. Vague answers that don't have a concrete situation, a concrete action, and a measurable result tend to score poorly.
The behavioral questions I've heard repeatedly: Tell me about a time you had to influence stakeholders without direct authority. Describe a situation where you had to deliver bad news to a client or leadership. Tell me about a time you made a decision with incomplete information. Give me an example of when you drove change in your organization.
All of these skew enterprise: stakeholder management, ambiguity tolerance, client-facing judgment. If your background is purely startup or consumer product, translate your experience into language that resonates with someone who sells software to Fortune 500 clients.
Timing and pacing: IBM debrief cycles can take a while. I've heard of candidates waiting 2+ weeks post-final round before hearing back. That's not necessarily a bad sign, their internal processes involve multiple approvals especially for band 7+. Ping your recruiter after 10 business days if you've heard nothing.
One thing that trips people up: IBM wants evidence of collaboration. Lone-wolf accomplishment stories consistently score lower than stories where you pulled in the right people and built something together.