Why avoid virtual calls in hot loops?
PICTURE THIS: DJANGO MVT
Simple meaning
Indirect calls hinder inlining.
WHY — Performance instead of guessing?
Why interviewers care about Performance:
on Performance.
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:
- 1Define it
Indirect calls hinder inlining.
- 2CRTP or final helpers
can help when profiling shows cost.
- 3Most apps are fine
with virtuals.
- 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
Indirect calls hinder inlining. CRTP or final helpers can help when profiling shows cost.