SIG (Susquehanna International Group) Interview Experience

I recently interviewed with SIG (Susquehanna International Group), and if I had to summarize the experience in one sentence:

High intensity, fast-paced, and extremely focused on real-time thinking under pressure.

SIG interviews feel very different from typical big tech interviews. There’s no long warm-up or gentle guidance.
They jump straight into questions, keep pushing, and clearly want to see whether you can
stay structured and clear-headed while being pressured.

First Round: HR / Phone Screen (Filtering Round)

This round moves quickly. The questions aren’t tricky, but you’re not given much room to ramble.

Along with basic background questions, they ask judgment-based ones like:

Why trading / quant / SIG?
How do you view high-pressure, high-intensity work?
Have you made important decisions with limited time or information?

What matters here isn’t sounding impressive — it’s whether your answers are
clean, logical, and to the point.

Technical / Quant Interview (The Core Challenge)

This is where the real “SIG style” shows up.

The questions mainly fall into these buckets:

Probability & expectation problems (classic, but constantly tweaked)
Logic reasoning & mental math, often without letting you write much down
Light coding or pseudo-code, where thinking matters more than syntax

The biggest takeaway for me:

Interviewers aren’t rushing to hear the final answer — they’re watching how you think.

Making a small mistake isn’t fatal. But once your reasoning becomes messy — or you lose track
of what you’re doing — things go downhill very fast.

Many questions don’t even have a single “correct” final answer. Instead, they keep pushing:

What if the condition changes?
What if probabilities aren’t uniform?
Can you estimate this faster?

This chain of follow-ups is extremely SIG.

Behavioral Round (Team Fit Check)

SIG cares a lot about fit.

Behavioral questions are short, direct, and sharp, such as:

What’s the worst decision you’ve made?
Have you ever decided with incomplete information?
What if your judgment conflicts with the team’s?

They’re essentially checking one thing:
Can you think independently under pressure, while still listening to others?

Overall Impression

This is not something you can brute-force with LeetCode.

You might have seen similar problems before, but under that pace and pressure, the ability
to react instantly, decompose problems, and self-correct makes a massive difference.

Personally, once I got stuck on one part, I could feel the pressure stacking up rapidly —
it’s very easy to spiral if you lose structure.

Practical Advice for Future Candidates

If you’re someone who:

Does fine practicing alone
But panics when aggressively questioned
Struggles with mental math or probability under pressure

SIG interviews can be brutal.

After reflecting, I honestly think that
having someone help manage pace and nudge you back on track at key moments
could completely change the outcome.

A Side Note for Those Who Want to Be More Confident

For SIG / Jane Street / IMC-style trading firms, many candidates do some form of
real-time, pressure-based preparation.

Services like ProgramHelp focus on:

Simulating SIG-style aggressive follow-ups
Providing real-time voice prompts when probability logic goes off-track
Training structured thinking under stress

It’s not about thinking for you — it’s about
preventing a mental collapse during the most critical five minutes.
For interviews with extremely low tolerance for mistakes, this kind of preparation can make a real difference.