NestJS · Senior · Question 12 of 75

Why can `class-transformer` serialization become a bottleneck for large responses?

1It runs on a separate thread
✓Correct answer: It walks every object and applies decorators via reflection; for big lists, mapping to plain DTOs or using schema serializers is faster
3It sends each field in a separate packet

Explanation

Measure with realistic payloads. Pagination also limits the cost.

Further reading

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