Switching within MBB as consultant - how to prepare case interview given limited prep time?

Hi Anonymous!

Let me answer this in a very grounded way, based on what I actually see in practice.

I work with around 10-15 people every year who lateral between McKinsey, BCG, and Bain at consultant level. They approach me because I made that move myself, from BCG to McKinsey. So what I’m about to say isn’t theory or second-hand advice.

First, yes, the bar will be higher. There’s no way around that.

Bain will not look at you like a graduate anymore. They will look at you like someone who has already spent a year inside an MBB firm and should have absorbed a lot by now. Implicitly, they’re asking themselves one question the whole time: did this person actually grow during their first year, or did they just survive it.

This is also why most online advice doesn’t really help at this stage. Case books, YouTube content, and “do X more cases” logic are designed for people who have never been trained as consultants. 

At your stage, they do more harm than good because they reinforce an approach that is too mechanical and far too shallow. If you haven’t gone through an MBB to MBB switch yourself, a lot of the important nuances are invisible.

One important thing to internalize: the number of cases you’ve done in the past does not matter much. Sixty cases a while ago is not a strong signal. What matters is how you now approach an unfamiliar problem under pressure. Are you crisp in framing the problem. Are you clearly hypothesis driven. Do you make judgment calls instead of hiding behind exhaustive structures. Bain will push on this much harder with you than with a grad.

Another point that people consistently underestimate is how the interview feels different. You’ll likely be interrupted earlier, challenged more directly, and given less guidance. That’s not because the interviewer is tougher. It’s because they assume you should already know how to drive the case yourself.

Where I see a lot of laterals stumble, though, is not even the case. It’s the behavioral part.

Bain expects consultant level stories. Not polished graduate narratives. They want to hear about real ownership, real conflict, difficult tradeoffs, pressure situations, and mistakes that actually mattered. If you prepare behaviorals the way most grads do, you’ll sound “fine” but not credible at the level they expect. This is something people only really understand after going through an MBB to MBB process once.

Given your time constraint, I’d be very selective.

I would not try to do many cases. I would rebuild fundamentals properly and pressure test them hard. I would practice cases where you’re interrupted and challenged, because that’s much closer to the real experience. And I would spend serious time on behavioral stories, making sure they reflect how you’ve grown as a consultant in your first year, not just what you achieved.

The biggest mindset shift is this: this is no longer about proving you are smart or hardworking. Bain assumes that already. It’s about showing that your thinking has evolved.

If you treat this like a graduate interview with better polish, it can feel comfortable and still go wrong. If you treat it like a calibration of how you think and operate as a consultant, you’re much closer to what Bain is actually testing.

If you want, feel free to reach out. I’m happy to sanity check whether your preparation focus makes sense for a Bain lateral, or whether you’re about to focus on the wrong things.

Hope this helps, and good luck with the process.

Sidi

____________________

Dr. Sidi S. Koné

Hi there,

Given your limited time, the goal isn’t to relearn casing but to sharpen Bain-specific execution. Focus on being crisp and pragmatic: simple structures, fast prioritization, strong exhibit reading, and clear top-down synthesis. Bain cases reward decisiveness and business judgment more than complex frameworks.

With only weekends available, prioritize quality over volume. Do a small number of full Bain-style cases under time pressure and spend most of the time refining synthesis and recommendations. At this stage, practicing with a coach is one of the most efficient ways to quickly recall and reinforce the good habits and tips you’ve built from past practice, rather than trying to start from scratch. I can help with that if useful - feel free to reach out!

Best
Evelina

In your case, just work with a coach. 

You already have the baseline you need. 

You just need to refresh your memory as to how casing works and to resharpen / update your value proposition. 

Working with a coach is the best return for your time, esp since you can only practice on weekends, you have a paid full time job and don't want to waste time with generic feedback from peer practice.

Do reach out if you need help. I've worked in previous situations with cross-MBB transfers.

Best,
Cristian

hey there :)

yeah.. the bar will indeed be higher, but the focus shifts more toward clean structure, sharp prioritization, strong synthesis and Bain style communication rather than relearning basics. I would refresh cases end to end, practice top down structuring and conclusions, and do a small number of high quality cases with very honest feedback instead of many repetitions. With limited time, revisiting classic profitability, market entry and growth cases and really polishing your opening structure and final recommendation is the most effective approach. 

I would just use a qualified coach to be efficient. 

best,
Alessa :)

Hi there,

Given the limited time, I suggest you working with a Bain coach to quickly assess where you should focus on sharpening.

Treat it like you are in a problem solving session with slight more structure

First round : ps with an em

Final rounds: how you would ps with a partner 

This is a great career move, and you are spot-on: the expectation for a lateral hire from a peer firm is significantly elevated. You are not being evaluated as a fresh university grad, but as someone who should be immediately deployable and operating with executive maturity.

Here is the reality of the lateral switch: your case performance needs to demonstrate not just structure (which they assume you already have from 60+ cases), but integrated synthesis and a strong commercial instinct. Where BCG often prioritizes rigorous, detailed hypothesis testing, Bain—especially in the late rounds—is looking for the direct P&L impact. They want to see you quickly identify the high-value 80/20 leverage points and integrate the answer fluidly, rather than just ticking off framework boxes. The single biggest mistake experienced consultants make is over-structuring without reaching a decisive, commercially-focused conclusion.

Given your limited time, your prep must be surgical. Forget grinding 10 more cases. Your most effective use of weekend hours involves two things: First, run 3-5 full, realistic partner-style interviews with high-quality partners or peers (ideally ex-Bain). Focus intensely on the synthesis, recommendation, and answering the final "Why are you recommending this specific action over A or B?" question. Second, spend the vast majority of your time refining your Personal Experience Interview (PEI) and, critically, your transition narrative. You need a bulletproof, enthusiastic, and sophisticated answer for "Why Bain, specifically, right now, given you are already succeeding at BCG?" This part of the interview is often the primary filter for lateral candidates; they are vetting culture fit and commitment before evaluating your casing, which they believe is largely known.

Focus less on how to solve and more on the impact and executive presentation of your solution. That polish is the difference between passing and failing at this stage.

All the best!