BCG does have commercial/sales roles, usually inside specific practice areas or in BCG X (their digital product arm). Applied to one of these about six weeks ago. Here's what I saw.
Title was something like 'Client Development Executive' which is essentially enterprise sales inside a professional services context. Different animal than a quota-carrying SaaS AE role, but the interview structure had a lot of overlap.
Phone screen: Standard recruiter call. They wanted to understand my enterprise sales background, average deal size, and specifically asked about selling into C-suite buyers. BCG's deals are big and the buyers are CEOs and Board members, so they're looking for someone who's comfortable in that room.
First round: Two interviewers. One asked about a complex multi-stakeholder deal I'd closed, specifically wanting to understand who the economic buyer was, who the internal champion was, and what the competitive dynamic looked like. Standard MEDDIC-style framing but they wouldn't call it that. The second interviewer ran a mini case: 'you're trying to grow BCG's footprint in financial services in a market where McKinsey dominates, what's your approach.' My instinct was to answer like a consulting problem, not a pure sales problem, and I think that was right.
Second round: Partner interview. Felt very exploratory. They asked what consulting firms could do better commercially and whether I'd seen any innovations in how professional services firms sell. Honest take: this round is mostly checking whether you can sit across from a senior partner and hold a conversation without flinching.
For AEs coming from SaaS: the big adjustment is that BCG's 'sales cycle' is measured in months or years and the deliverable is intangible expertise, not a software seat. The way you talk about pipeline management and relationship development needs to translate to that context.