Learn how to implement instant replays / killcams via this detailed article by Vorixo.
Topics
Lazy loading the Ability System Component (GAS) in Multiplayer games
Rewinding a networked game
Unreal Engine - The magic of Network Managers (Networking optimization)
The Unreal Engine Game Framework: From init main() to BeginPlay
Unreal Engine Multiplayer Tips and Tricks
Unreal Engine Network Compendium
How to make tools in Unreal Engine
Making UIs With C++ in Unreal Engine