The First 90 Days: 3 Mistakes to Avoid as a New Consulting Analyst

Landing a job at McKinsey, BCG, or Bain feels like reaching the summit of a mountain. But within weeks of starting, many new analysts realize they've actually just reached base camp. The real climb—building a successful consulting career—is just beginning.

The first ninety days are make-or-break for new consultants. During this period, you'll form the professional relationships, work habits, and reputation that will define your entire tenure at the firm. The analysts who excel during this window set themselves up for fast-track promotions and choice project assignments. Those who stumble often spend years trying to recover.

After observing hundreds of new consultant journeys across top firms, three critical mistakes emerge as the primary reasons promising analysts struggle. The good news? Each of these mistakes is completely avoidable with the right awareness and approach.

Mistake #1: Trying to Prove You're the Smartest Person in the Room

This mistake stems from a fundamental misunderstanding of what made you successful in school versus what makes you successful in consulting. In academic settings, being the smartest often meant having the right answer first, demonstrating superior analytical ability, and outperforming peers on individual tasks. These instincts, while valuable, can be counterproductive in your early consulting career.

New analysts who fall into this trap constantly volunteer for the most complex analysis, jump into conversations with solutions before fully understanding the problem, and subtly compete with teammates rather than collaborating. They might interrupt senior team members to correct minor points, spend excessive time perfecting analyses to showcase their technical skills, or dismiss ideas from others too quickly.

The problem with this approach becomes clear when you understand how consulting teams actually function. Success depends on trust, collaboration, and making the entire team more effective—not individual brilliance. Senior consultants and partners are evaluating your judgment, not just your analytical horsepower. They want to know: Can you be trusted with client relationships? Do you make the team's work better? Will you represent the firm well in high-stakes situations?

When you focus on proving your intelligence rather than adding team value, you signal poor judgment and limited emotional intelligence. Partners notice when new analysts seem more interested in showcasing their skills than solving client problems. This perception, once formed, is difficult to change.

Instead, channel your intelligence toward understanding what your team actually needs. Ask thoughtful questions that demonstrate you're thinking strategically about the engagement. Volunteer for tasks that may be less glamorous but are critical to project success. When you do contribute insights, frame them as building on others' ideas rather than replacing them. For example, instead of saying "Actually, I think the real issue is..." try "Building on what Sarah mentioned about market dynamics, I wonder if we should also consider..."

Remember that your job in the first ninety days is to become someone your teammates want to work with again. Technical skills got you hired, but interpersonal effectiveness will determine your career trajectory. The analysts who thrive are those who make their senior colleagues think, "I want this person on my next project."

Mistake #2: Staying in Your Analytical Comfort Zone

Consulting interviews focus heavily on analytical problem-solving, which leads many new analysts to believe that technical analysis is their primary value proposition. This mindset causes them to gravitate exclusively toward quantitative tasks like building financial models, conducting market research, or creating detailed process maps while avoiding anything that feels subjective or ambiguous.

This approach severely limits your development and value to the team. While analytical skills are important, they represent only one facet of consulting work. Client relationships, strategic thinking, project management, and communication are equally critical—and often more differentiating at senior levels.

New analysts who stay in their analytical comfort zone miss crucial learning opportunities. They volunteer only for spreadsheet work while avoiding client meetings, stakeholder interviews, or presentation development. They focus on perfecting their models while neglecting to understand how their analysis fits into the broader project narrative. They become known as "the numbers person" rather than developing into well-rounded business advisors.

The career implications of this mistake become apparent within months. These analysts often receive feedback that they need to develop their "business judgment" or "client skills" without understanding how to make this transition. They may excel at technical work but struggle to get promoted because they haven't demonstrated the broader skill set required at senior levels.

Breaking out of this comfort zone requires intentional effort and some courage. Volunteer for tasks that stretch your abilities, even if you're not certain you'll excel immediately. Ask to join client calls as an observer, even if you're not presenting. Offer to help with slide development, proposal writing, or stakeholder management. Request feedback not just on your analytical work, but on your communication, project management, and strategic thinking.

Seek diverse experiences within your first few projects. If you're naturally strong with numbers, volunteer to conduct stakeholder interviews. If you're comfortable with research, ask to help develop client-facing presentations. Each new challenge builds capabilities that will serve you throughout your career.

Most importantly, reframe your relationship with uncertainty and ambiguity. In school, problems typically had clear parameters and correct answers. In consulting, you'll often work with incomplete information, conflicting stakeholder perspectives, and situations where multiple approaches could be valid. Learning to navigate this ambiguity with confidence is one of the most valuable skills you can develop.

Mistake #3: Focusing on Tasks Instead of Relationships

New analysts often approach their role like an individual contributor position, focusing intensely on executing their specific assignments while paying little attention to the broader team dynamics and relationships. This task-focused mindset misses the fundamental reality that consulting is a relationship business at every level.

These analysts complete their work efficiently and accurately but operate in isolation. They attend meetings but don't contribute to team building. They deliver what's asked but don't anticipate what's needed. They interact professionally with colleagues but don't invest in getting to know them as people. They view their role as executing tasks rather than being a valuable team member.

This approach limits your effectiveness and career prospects in multiple ways. Without strong relationships, you don't get access to informal information that helps you understand project context and client dynamics. You miss opportunities to learn from senior colleagues who could become mentors. You don't get considered for stretch assignments or interesting projects because partners don't think of you as someone they want to develop.

Building effective relationships requires intentional investment beyond just doing good work. Take time to understand your colleagues' backgrounds, interests, and career goals. Offer help proactively when you see teammates struggling with deadlines or complex problems. Participate in team social activities, even when you're tired after long work days. Show genuine interest in your projects beyond just your specific deliverables.

Develop relationships with people across experience levels, not just those senior to you. Your analyst peers will become your future collaborators and potentially your future clients. Building strong relationships with this cohort creates a network that supports your entire career. Similarly, be generous with your time and knowledge when new analysts join after you.

Pay special attention to administrative staff, who often have significant influence over scheduling, resources, and project logistics. Building positive relationships with these team members can make your work life much easier and demonstrates the kind of judgment that senior colleagues notice and value.

Understand that relationship building isn't about being social for its own sake—it's about becoming the kind of colleague that others actively want to work with. When partners are staffing new projects, they consider not just who can do the work, but who will make the team more effective and enjoyable to work with.

The Strategic Mindset: Thinking Beyond Your First Assignment

Avoiding these three mistakes requires adopting a strategic mindset about your career development from day one. Instead of thinking only about your current task or current project, consider how each experience contributes to your long-term success at the firm.

This means viewing every interaction as an opportunity to build your reputation and relationships. When you receive feedback, don't just fix the immediate issue—understand what it signals about areas for your development. When you complete assignments, reflect on what you learned that you can apply to future work. When you meet new colleagues, think about how you can add value to their work over time.

Develop the habit of thinking one level above your current role. If you're an analyst, try to understand the associate perspective on your project. What challenges are they facing? How can you make their job easier? This kind of strategic thinking signals maturity and leadership potential that partners notice and value.

Seek feedback proactively and regularly, not just during formal review periods. After completing significant deliverables, ask your project manager or senior colleague for specific feedback on both your work quality and your approach. Most importantly, demonstrate that you act on the feedback you receive by making visible changes to your approach.

Building the Foundation for Long-Term Success

Your first ninety days establish patterns that will define your entire consulting career. The work habits, relationship skills, and professional reputation you develop during this period create momentum that either accelerates or constrains your future opportunities.

Successful new analysts understand that excellence in consulting requires much more than analytical ability. It demands emotional intelligence, strategic thinking, relationship building, and the ability to add value in ambiguous situations. These skills can't be developed overnight, but the foundation must be laid immediately.

Remember that everyone expects new analysts to have a learning curve on technical skills and firm processes. What distinguishes the future stars is their approach to learning, their investment in relationships, and their ability to think beyond their immediate responsibilities. Partners are looking for analysts who demonstrate the judgment and interpersonal skills that predict success at senior levels.

The consulting firms that recruited you made a significant investment in your potential. They've provided you with an extraordinary platform for learning and growth. Your job in the first ninety days is to prove that their investment was wise by demonstrating not just that you can do the work, but that you can grow into the kind of consultant who drives the firm's future success.

Your Action Plan for the First 90 Days

Start each week by identifying one relationship-building goal alongside your task-oriented objectives. This might mean having coffee with a colleague from a different practice area, volunteering to help a teammate with their presentation, or asking a senior consultant about their career path.

Actively seek diverse experiences within your early projects. If you've been focused on quantitative analysis, volunteer for stakeholder interviews. If you've been doing research, ask to help with client presentation development. Each new challenge builds the broad skill set that consulting demands.

Establish regular check-ins with your project managers and mentors. Don't wait for formal feedback cycles—proactively ask for input on your performance and development areas. Most importantly, demonstrate that you're acting on the guidance you receive.

Document your learning and experiences during these first months. Keep track of the projects you work on, the skills you develop, and the relationships you build. This foundation will serve you well in future performance reviews and career planning conversations.

The transition from student to consultant is significant, but it's also an incredible opportunity to accelerate your professional development in ways that few other careers offer. By avoiding these common mistakes and focusing on building the broad skill set that consulting demands, you can set yourself up for a successful and rewarding career trajectory.

Your first ninety days aren't just about surviving—they're about establishing yourself as the kind of consultant who will thrive in this demanding but rewarding profession. The investment you make in building relationships, developing diverse skills, and thinking strategically about your role will pay dividends throughout your entire career.