Types of firm: MBB, Big Four and boutiques

Before you send your first application, you need to understand the types of consulting that exist and the real differences between firms — not the ones that appear on their corporate pages, but the ones you feel day to day. Not all consulting firms are the same. They don't all do the same type of work, they don't pay the same, they don't offer the same career prospects, and they don't have the same internal culture. And the firm you choose is going to define your experience over the next few years in a way many candidates don't anticipate. This guide compares the different tiers of consulting firms — from MBB to specialized boutiques — from the perspective of someone who has worked for over 8 years inside one of the three big names and has collaborated professionally with people from all categories.

Tier 1 — MBB: McKinsey, BCG and Bain

McKinsey, BCG, and Bain are the three most prestigious strategy consulting firms in the world. They're grouped under the acronym MBB because they share a level of excellence that sets them apart from the rest in multiple dimensions: talent, knowledge, accumulated experience, brand, quality of work, standards, and level of clients. They're among the few consulting firms that by default sponsor your MBA — a benefit that says a lot about the investment they make in their people.

But MBB isn't a monolithic bloc. Each firm has its own culture, and that matters more than most candidates think. Bain stands out for an exceptionally close, friendly, and trusting internal culture — there's a phrase that sums it up: "a Bainie never lets another Bainie fail." It's an environment where collaboration isn't a slogan, it's the real way of working. McKinsey has a very structured and powerful organization, an efficient machine where relationships of trust between professionals are solid and productivity is a reference in the sector. BCG has a more formal profile, though with a strong reputation for innovation and independent thinking.

What type of person fits better in each one? The honest answer is that the differences are more subtle than the rankings suggest. My recommendation to every candidate is always the same: choose the place that you liked the most and where you got better feelings during the process. Consulting work at MBB is very complex — many hours, a huge level of demand, surrounded by brilliant people who evaluate you every six months to make sure you're up to the level. The least you can do is be able to enjoy the work in a place and environment where you want to be.

As for career, type of projects, promotion pace, and salary, the differences between the three MBBs are minimal. What really changes is the culture, the type of relationships you build, and how it feels day to day. And that you can only evaluate by talking to people from each firm through networking.

Tier 2 — Core Firms: Strategy&, Oliver Wyman, Roland Berger, Kearney and LEK

Tier 2 consulting firms are strategy consultants with an excellent reputation, high-level projects, and a very powerful professional exit. Receiving an offer from any of them is an enormous professional success, whether it's in the United States, Spain, or Mexico.

Of all of them, Kearney and LEK are the ones perceived as closest to MBB in quality of projects and professional career. Kearney has a strong presence in operations and supply chain, with relevant offices in Spanish-speaking markets. LEK stands out for its work with private equity funds and strategic due diligences.

Strategy& (part of PwC) has an interesting position: it was born as Booz & Company, a pure strategy consulting firm, and maintains that strategic DNA within the PwC ecosystem. Oliver Wyman is heavily specialized in financial services and has a more quantitative profile. Roland Berger is the reference outside the Anglo-Saxon consulting world in Europe, with strong presence in Germany, Spain, and parts of LATAM.

Each one has its sectoral and geographical strengths. Don't automatically rule them out for not being MBB — in many cases, the type of work you do and the experience you gain is comparable, and the professional exit is excellent.

Tier 3 — Big Four in strategy consulting: Deloitte, EY, PwC and KPMG

The Big Four — Deloitte, EY-Parthenon, PwC (Strategy&), and KPMG — are enormous companies with strategy consulting practices that have grown significantly in recent years. Deloitte Strategy & Analytics and EY-Parthenon in particular have made aggressive hires of ex-MBB talent to raise their strategy practice.

The question candidates ask most is: is Big Four strategy consulting comparable to MBB? The answer, based on direct experience working with ex-Big Four consultants, is that it's not as comparable. At the operations consulting level, Big Four firms are very good. But at the level of pure strategy consulting, the level is not the same.

After working on projects alongside ex-Big Four consultants, the difference is noticeable. It's not a matter of individual people — there are brilliant people everywhere — but of the ecosystem. The reason is structural: consulting is a business of people and talent. When that talent is enhanced with accumulated expertise from thousands of previous cases and with access to first-rate experts who make the difference, the result is a different product. If the talent isn't as potent, or if there aren't as many previous cases to reference, or if there aren't as many experts making the difference, it becomes difficult to be at the same level.

That said, Big Four firms offer real advantages: greater stability, larger offices in more cities, a wider range of services, and in many cases, more accessible entry than MBB. For a candidate who prioritizes stability over maximum prestige, or who wants to specialize in a sector where the Big Four has a strong practice, they can be a very valid option.

What's important to be clear about: no Big Four firm pays the same as an MBB, at least not in the major markets of the world. If salary is a decisive factor in your choice, research the concrete figures for your market before making a decision.

Tier 4 — Specialized boutiques: when they're the best option

Strategy consulting boutiques are smaller firms, often specialized in a specific sector or type of work. There are boutiques for private equity, healthcare, technology, restructuring. And in some cases, the quality of work you do and the experience you gain is exceptional.

The question "MBB or boutique?" doesn't have a universal answer. It depends on what excites you. Consulting work is very hard — many hours, high demand, constant pressure. Do what makes you happy. Working at a boutique of something you're passionate about is an incredible experience with enormous professional development potential.

Where boutiques don't compete with MBB is in brand and breadth of post-consulting opportunities. An ex-McKinsey or ex-Bain has access to a universe of opportunities after consulting — corporates, private equity, startups — that's difficult to replicate from a boutique. But if your plan is to specialize in a sector and grow within it, a specialized boutique can give you a depth of experience that MBB doesn't always offer.

MBB offices in Spain and LATAM: what to expect

MBB offices in Spain (Madrid and Barcelona) and LATAM (São Paulo, Mexico City, Bogotá, Buenos Aires, Santiago) are smaller than those in New York, London, or Munich. They hire fewer people, but they also receive fewer applications — the ratio of competition is similar.

As for the type of work, smaller offices tend to be more focused on the sectors where partners have expertise, with more diverse cases appearing only occasionally. If you're looking for real diversity, big offices are a better option — they have more specialized teams, more active clients, and more rotation between projects from different industries.

Salary differences exist between geographies, adjusted to local cost of living, but career progression within the firm follows the same global structure. A consultant in Madrid has the same promotion opportunities and international transfer options as one in Chicago.

To understand the specific selection process of each firm and office, check out our guide to the consulting recruitment process.

Myths and realities about consulting firms

There are a number of myths circulating among candidates that are worth debunking with real data:

"McKinsey only hires from INSEAD and Harvard" — False. There are McKinsey consultants from an enormous variety of universities and programs. Target universities make access easier, but they're not the only way.

"You work less at Bain than at McKinsey" — It depends on the office, the project, and the time. There are Bain offices where you work more than in some McKinsey offices, and vice versa. Generalizing doesn't make sense.

"Big Four pay the same as MBB" — Not true in the main markets of the world. The salary difference is significant, especially in the first years and at the bonus level.

"It's impossible to enter MBB from LATAM or Spain" — Absolutely false. Spain and LATAM offices hire each cycle. Maybe they're smaller offices and they hire fewer people, but the number of people who apply is also smaller. The process and level of difficulty are the same.

If you have specific questions about a particular firm or market, you can write to us through the contact section.

About independent rankings: according to the Vault Consulting 50 (2026), the industry ranking based on surveys of ~10,000 real consultants, Bain leads as the best firm to work for in North America and EMEA, and McKinsey tops the prestige ranking (8,906/10, followed by Bain with 8,882 and BCG with 8,854). BCG stands out especially in satisfaction, benefits, and work-life balance. McKinsey has not participated formally in the ranking for three years. Beyond the numbers, what matters: the difference between the three MBBs is minimal — what separates them from the rest of the sector is enormous.

Frequently asked questions about types of consulting firms

What's the real difference between MBB and Big Four strategy consulting?

The fundamental difference is in talent, accumulation of expertise, and level of clients. MBB works with CEOs and boards of the world's largest companies on their most critical decisions. Big Four has growing strategy practices, but their core is still audit, tax, and operations consulting. For the candidate, this translates into different projects, different career pace, and different post-consulting opportunities.

How do I choose between McKinsey, BCG, and Bain if I have the option?

My advice is to choose the firm where you felt best during the process: the one that gave you the best feelings, where you connected with people, where you imagine working the next years. The differences in salary, projects, and career between the three are minimal — what changes is the day-to-day culture.

Is it worth applying to a Tier 2 firm if my goal is MBB?

Yes. Tier 2 firms are excellent in themselves. Plus, experience at a firm like Kearney, LEK, or Oliver Wyman can be a springboard to MBB later, especially after an MBA. Don't see them as a "consolation prize" — they're spectacular firms with great professional development.

Are boutiques a good option if I don't get into MBB?

It depends on your motivation. If you're passionate about a specific sector and the boutique is a leader in it, it might be a better option than MBB for you. If what you're looking for is the brand and breadth of post-consulting opportunities, MBB or Tier 2 will be more appropriate.

What firms have the most presence in Spain and LATAM?

The three MBBs have offices in Madrid, São Paulo, and Mexico City. BCG and McKinsey are also in Barcelona and Bogotá. Of Tier 2, Roland Berger and Kearney have strong presence in Spanish-speaking markets. Of Big Four, all have massive presence in Spain and LATAM, with variable-sized strategy consulting practices.

Knowing the firms before applying is not a luxury — it's part of the preparation work. The candidate who can explain why they want to work at that specific firm, in that specific office, has a huge advantage over someone who simply "wants to get into consulting." This shows in the resume, in the cover letter, and in the interview. Knowing the firms is the step before choosing where to apply. The next step is understanding how the selection process actually works at each one. Crack The Interview Process covers exactly that — from the perspective of someone who participated in that process from inside for over 8 years at Bain. Available at nextepmbb.com/resources. And for a global view of the entire process, check out our complete preparation guide for consulting.