Why do product teams often prefer composition over inheritance?
PICTURE THIS: DATA SPLIT
Fit on train, tune on val, report on test once.
Simple meaning
Inheritance couples you to a parent class and leaks implementation details into subclasses.
WHY — OOP instead of guessing?
Why interviewers care about OOP:
on OOP.
the situation, the default choice, and one exception - that reads as experience.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Inheritance couples you to
a parent class and leaks implementation details into subclasses.
- 2Composition lets you plug
in a helper object, which is easier to test and change.
- 3Prefer extends only for
a true is-a relationship, not just to reuse a few methods.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Inheritance couples you to a parent class and leaks implementation details into subclasses. Composition lets you plug in a helper object, which is easier to test and change.