When would you choose a Linked List over an Array?

Difficulty: 5/10

insertion/deletion performance, memory allocation, cache locality

Choosing a Linked List

I would choose a linked list only when its structural properties provide a real advantage over an array or array-backed collection. In modern systems, I would first evaluate workload characteristics because arrays generally have better cache locality and lower memory overhead.

1
Frequent insertion and deletion where node references are already available.
2
Workloads where contiguous memory allocation is undesirable or difficult.
3
Structures naturally represented through links between nodes.
4
Cases requiring stable node references under insertion or deletion, depending on the language and collection semantics.
5
Avoid linked lists when frequent random access is required.
6
Avoid them when memory locality and iteration performance are more important than cheap structural modification.

Scenario Questions

0-2 years experience

1We need a simple text editor buffer that supports inserting characters at the cursor. Would you choose a linked list or an array, and why?
2If you have a fixed‑size list of user IDs that never changes after initialization, which data structure would you pick and what’s the reasoning?
3What happens to the time complexity of inserting an element at the beginning of a linked list versus an array?

Follow-up Questions

How would you mitigate memory fragmentation in a long‑running linked list?
What role does cache locality play in the performance difference between the two?
Is there a hybrid structure that gives you the best of both worlds?