Summer Analyst

Initial Contact & Application
I applied online through William Blair's careers portal (williamblair.com/ibcareers). Within 48 hours of submitting, I received an automated email with a link to complete the Suited assessment — a personality/cognitive pre-screening tool. There's no real way to prep for it; it tests judgment and soft skills more than finance knowledge. I'd advise not overthinking it, just answer authentically. Make sure to check your spam folder since the link sometimes lands there.
Roughly two to three weeks after submitting, I received an email to schedule my first round interview. I had done some light networking beforehand — I'd connected with a couple of analysts on LinkedIn who were responsive and friendly, which I think helped signal genuine interest.
First Round Interview
A 30-minute Zoom with a second-year analyst (in some cases a VP or Director, depending on office). The format was roughly half behavioral, half technical.
Behavioral questions included the standard: tell me about yourself, why investment banking, why William Blair specifically, and something not on your resume. They go fairly deep on "why Blair" — you need a real answer about the independent partnership structure, culture of accountability, boutique deal exposure, or a specific group you're interested in. Vague answers don't fly here.
Technical questions included: walk me through a DCF, enterprise value vs. equity value, and most importantly — a paper LBO. The paper LBO is a defining feature of Blair's interview process and comes up at almost every stage. Know it cold. Be able to walk through entry/exit, debt paydown, IRR calculation, and key value drivers verbally and on paper without hesitation.
I got a superday invitation about two hours after the first round ended, which was a great sign.
Superday
Four back-to-back 30-minute interviews, all one-on-one. The interviewers were mostly MDs and Directors, with one Associate.
Round 1 (MD) — Behavioral + mini case study. Started with TMAY. Then they presented a brief business scenario and asked me to think through it — somewhat consulting-flavored but they tied it to M&A, asking about comparable transactions and what kind of buyer would be interested. Stay calm and structured.
Round 2 (MD) — Resume-based + markets. Heavy on "why Blair, why this office, why this group." Also asked about an industry I follow, a company I find interesting, what differentiates it competitively, and what the key risks are. Know a sector cold — ideally one relevant to Blair's coverage areas (healthcare, tech, industrials, consumer).
Round 3 (MD) — Pure behavioral. Be ready for situational/ethical questions like: "What would you do if you caught a mistake in a pitchbook the night before a client presentation?" They want to see judgment, teamwork instincts, and maturity under pressure.
Round 4 (Associate) — LBO focused. This is where they really stress-test technical depth. They gave me the paper LBO in parts, almost like a guided walkthrough, but pushed back on assumptions and asked about key drivers of IRR improvement (debt paydown, multiple expansion, EBITDA growth). Know your LBO levers inside and out.