The SIG SWE / Quant-Dev Coding + Systems interview is stage 7 of 7 in the SIG interview process, after the Onsite / Superday. Format: Phone + onsite · C++ / algorithms / system design. The engineering funnel.
Preparing for this round? Practice the 19 questions mapped to the SIG SWE / Quant-Dev Coding + Systems, with worked solutions. A free account saves your progress.
What the SWE / Quant-Dev Coding + Systems tests
After the CodeSignal test, a C++ phone screen centred on building a standard container from scratch (growth policy, memory management, exception safety, ownership), then an onsite covering pointers, polymorphism and virtual functions, an order-book system design (price-level matching and the data structures behind it) and live C++ debugging.
QuantVault maps 19 practice problems to this round. By topic, the biggest groups are coding (19); by difficulty, 5 easy, 10 medium and 4 hard. 19 of them were reported by candidates who interviewed at SIG, most recently in Jun 2026.
Who takes this round: Software Engineer / Quant Strategy Developer candidates. See the full SIG process and who takes each round.
How to prepare for the SWE / Quant-Dev Coding + Systems
- Be able to implement a vector end-to-end. Growth policy, allocation/deallocation, exception safety, and move semantics — this is the signature SIG dev question.
- Know the trade-book design. Price-level matching with the right data structure (sorted map vs heaps) and the trade-offs.
- C++ internals come up live: virtual dispatch/vtables, smart pointers, RAII, struct padding.
Final-week checklist
- Bayes tables + geometric-probability + coin-pattern classics, reflexive
- 5-dice mahjong reroll EV; bold-betting Markov; frog no-3-consecutive DP
- Market-making spread game + AKQ / Acey-Deucy poker EV
- Take-home (3 days): counterparty analysis, defend EDA, present it on-site
- SWE: implement std::vector + trade-book system design (C++)
Further reading: How quant superdays work · C++ and low-latency interview questions · Behavioral questions at trading firms · Market-making game interview guide.
Question types in this round
The 1 largest question types in the SIG SWE / Quant-Dev Coding + Systems practice set; across them the most common sub-topics are arrays, data structures, string algorithms, complexity analysis, hash maps, sorting and searching. The questions themselves, with worked solutions, are in the round practice.
Coding19 in this round
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Frequently asked questions
What is the SIG SWE / Quant-Dev Coding + Systems interview?
It is stage 7 of 7 in the SIG interview process, after the Onsite / Superday. Format: Phone + onsite · C++ / algorithms / system design. The engineering funnel.
What questions come up in the SIG SWE / Quant-Dev Coding + Systems interview?
The practice set QuantVault maps to this round centers on coding.
How should I prepare for the SIG SWE / Quant-Dev Coding + Systems interview?
Be able to implement a vector end-to-end. Growth policy, allocation/deallocation, exception safety, and move semantics — this is the signature SIG dev question. Know the trade-book design. Price-level matching with the right data structure (sorted map vs heaps) and the trade-offs.
What comes after the SWE / Quant-Dev Coding + Systems?
Nothing: it is the last of the 7 stages QuantVault maps for SIG.
Practice the SIG SWE / Quant-Dev Coding + Systems round
Work the 19 mapped practice problems with progress tracking, then move to the next stage of the SIG funnel.