C++ interview practice for quant developers
Answer C++ questions out loud the way a trading firm’s deep dive asks them: what a construct costs, when it is undefined, and how you would measure it. Vera probes each answer once or twice, then moves on.
- 35 min
- Six at regular, five at lead
- At most one small hint
- Quant developer (C++)
How the round runs
- 01
The question
Vera asks one question, such as what a virtual call costs on a hot path, and lets you answer. Say how it works, then what it costs.
- 02
Probes for depth
One or two follow-ups on the same idea: why it works, what breaks if a condition fails, when you would not use it.
- 03
The next question
Once there is enough signal, Vera moves on. Vera does not teach during the round; the report says what was missing.
What the report scores
Each skill gets a score from 1 to 5 against the bar for your level, with the quotes it is based on and the time you said them. The report ends with one thing to fix next.
- Accuracy
- Depth
- Practical judgment
- Communication
At lead level, also: Breadth and connection.
How the real round works
At trading firms the C++ deep dive is a 45 to 60 minute conversation about what code costs on real hardware: object lifetime and copies, move semantics, templates against virtual calls, undefined behavior, memory ordering and cache effects. Often you read a snippet and say what it really does. The guides we read agree that reciting a rule is only the baseline; the signal is saying what a construct costs and how you would measure it.
How C++ interviews for quant developers work: structure, signals and common mistakesRegular and lead level
- Regular
- Accurate answers that explain how a construct works and what it costs, with a real example of when it matters.
- Lead
- Also breadth and connection: tie each answer to what it does to the system, such as tail latency, and to the team’s decisions.
Length: 35 minutes at either level.
See the feedback before you start
Full reports from the real report pipeline, for a fictional student and a scripted interview.
Questions
What does the C++ deep dive cover?
Data layout and the cost of a virtual call, move semantics and copy elision, undefined behavior, templates, memory ordering and atomics, false sharing, allocation on a hot path and tail latency. Some questions cover market structure, numerical methods and the systems around a trading engine.
Do I write code in this round?
The questions are asked and answered out loud. Writing code is the separate coding round of the quant track, with a performance and memory focus.
Will Vera tell me the right answer?
No. Vera probes for depth and gives at most one small hint in the round. The report afterwards shows what was strong and what to work on next.
Is there a sample report for this round?
The linked sample is a general example of the same format: a machine learning theory round, which runs the same way and is scored on the same skills.