Overthrow the hierarchy!

Identifying design patterns in C++ code

This is an easy practice question that asks you to recognise a classic design pattern from a code snippet. Questions of this type appear in technical interviews at quant firms and other software-heavy organisations as a quick check that you understand foundational object-oriented design principles.

The question tests whether you can read unfamiliar code, spot the structural or behavioural intent, and name the pattern correctly. Success requires familiarity with the Gang of Four catalogue of patterns: recognising how classes relate to each other, what responsibility each plays, and which problem the pattern solves. Interviewers often follow up by asking you to explain why this pattern was chosen and what trade-offs it involves.

• Creational, structural, and behavioural patterns
• Class hierarchies and inheritance relationships
• Encapsulation and abstraction in design
• Problem-solution matching in code architecture