Most developers say:
“It is a faster array.”
That’s wrong — and will fail a senior interview.
❌ Bad answer
It is a faster array.
✅ Senior answer
Span<T> is a lightweight struct that provides safe access to contiguous memory without allocations. It can point to stack memory, arrays, or unmanaged memory, helping reduce allocations and improve performance.
int[] arr = {1, 2, 3, 4};
Span<int> slice = arr.AsSpan(1, 2);
// slice = {2, 3}Span avoids allocations → less GC → better performance in high-throughput systems like APIs and real-time processing.
❌ Trying to store Span in class fields
Span must stay on the stack → cannot be stored in heap objects.
❌ Overusing Span
Adds complexity when not needed.
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