What Do Consultants Do? A Day in the Life, Explained

Consultants produce one of two things: a recommendation or a capability.

A recommendation is a set of conclusions about what a company should do, typically delivered as a slide deck. "You should exit these two markets, double investment in this one, and restructure your supply chain by Q3 of next year." The client's job is to decide whether to follow it. The consultant's job is to make the recommendation so well-supported and clearly argued that the decision is easy. This is what most MBB engagements look like.

A capability is something the client can use after the engagement ends: a new operating model, a financial planning process, a trained internal team, a technology system. This is closer to what Big 4 and implementation-focused boutiques produce. The deliverable is not a deck. It is a change in how the organization works.

Both types of work require the same underlying skills: structuring a complex problem, gathering and analyzing the right information, and communicating clearly to people who are skeptical and busy. The differences in what MBB versus Big 4 firms actually produce are sharper than most candidates realize — the Big 4 vs MBB comparison walks through those distinctions in detail.

The day varies sharply by level, but the core rhythm is consistent across levels: client interaction in the morning, analysis and building in the afternoon, internal team coordination throughout.

A first-year analyst or associate spends most of their time in analysis: building financial models, synthesizing interview notes, pulling industry data, and turning raw information into exhibit-ready charts and tables. The first-year job is to produce accurate, clear analytical inputs that more senior team members turn into client-ready content. Expect to spend six to ten hours a day in spreadsheets and slide decks.

A manager or senior consultant owns a work stream: a defined piece of the engagement with their own analysis team, their own client contact, and their own section of the final deliverable. They divide their time between directing the analysis, presenting interim findings to the client, and synthesizing their work stream into the team's overall recommendation.

A partner manages the relationship. They are in the room with the CEO, running the steering committee, and making judgment calls about what the recommendation should be before the analysis is complete. Partners work from pattern recognition built over decades. They know what the answer is likely to be and they use the analysis to confirm or challenge it.

Practice this framework on a real case: the Amazon Whole Foods 2017 case on BoardroomIQ simulates a real engagement where every level of that team would have been working simultaneously on different parts of the problem.

The most cynical answer is that companies hire consultants to get cover for decisions they have already made. That happens. But it is not the main reason.

Companies hire consultants for four legitimate reasons. First, capacity: the internal strategy team has three people and the CEO needs a hundred slides in six weeks. Second, expertise: the company is entering a market where consultants have done this same analysis twelve times and the internal team has never done it once. Third, objectivity: the politics inside the company make it impossible for any internal person to tell the CFO that his division is underperforming. A third party can say it. Fourth, credibility: a board or investor audience takes a McKinsey-stamped recommendation more seriously than an internal memo, and the company knows it. Understanding what consultants earn at MBB makes it easier to understand why clients pay the fees they do — the bill rates are a direct function of the comp structure.

The best consultants understand which of the four reasons they were hired for and tailor their work accordingly. A project hired for objectivity needs different outputs than a project hired for capacity.

The skills the case interview tests are exactly the skills the job requires, which is why the interview format exists.

Structuring a problem: breaking an ambiguous question into a set of specific, answerable sub-questions. Analyzing with speed and accuracy: getting to the right number fast and understanding what it means. Communicating the answer: delivering a clear, confident recommendation to a skeptical senior audience. Adapting: changing your recommendation when new information changes the picture, without losing the client's trust.

The case interview is a compressed simulation of all four. That is why firms use it.

Read one consulting engagement write-up per week. McKinsey, BCG, and Bain publish case studies on their websites. Read one per week and ask yourself: what was the client's real problem, what did the team recommend, and how did they reach that conclusion? After ten case studies, you will understand consulting work better than most candidates who spent the same time reading case frameworks. The McKinsey vs BCG vs Bain comparison gives you a useful lens for understanding how each firm's work style shapes what their case studies tend to look like.

Interview a consultant about their last project. Ask one question: "Walk me through what your last project actually produced and who used it." The answer will teach you more about the job than any job description. It will also give you real material for "why consulting" answers.

Practice the "so what" discipline. After every analytical step in a case, ask "so what does this mean for the client?" out loud. If you cannot answer, you did the analysis but missed the consulting. That habit, built before your interviews, is what separates candidates who think like analysts from candidates who think like consultants.

The best way to practice what consultants do is under realistic pressure, with a case that fights back.