How to measure performance, pin-point bottlenecks and compare solutions in Unreal. Use console commands: stat fps, stat unitgraph, stat SceneRendering, stat gpu. Record profiling data as a graph.
Get project files: https://techartaid.com/products/
All parts playlist: https://www.youtube.com/playlist?list=PLF8ktr3i-U4A7vuQ6TXPr3f-bhmy6xM3S

Thanks to early reviewers: Mikołaj Fabjański and Ch Hope.

Links and sources:
[1] "Optimizing and Profiling Games With Unreal Engine 4": http://vincentloignon.com/blog/optimizing-and-profiling-games-with-unreal-engine-4/
[2] "UE4 - Overview of Static Mesh Optimization Options": http://www.casualdistractiongames.com/single-post/2017/01/07/UE4---Overview-of-Static-Mesh-Optimization-Options
[3] UE4 docs on GPU profiling: https://docs.unrealengine.com/latest/INT/Engine/Performance/GPU/
[4] Stat commands' output explained (for UE3): http://www.hourences.com/tutorials-ue3-performance-profiling-introduction/

Learn how to use Intel's external GPU profiler with Unreal Engine 4. Track performance bottlenecks down to a single heavy mesh or light.
Get project files: https://techartaid.com/products/
All parts playlist: https://www.youtube.com/playlist?list=PLF8ktr3i-U4A7vuQ6TXPr3f-bhmy6xM3S

Links and sources:
[1] "Intel Graphics Performance Analyzers": https://software.intel.com/en-us/gpa
[2] "Unreal Engine 4 Optimization Tutorial": https://software.intel.com/en-us/articles/unreal-engine-4-optimization-tutorial-part-1
[3] RenderDoc, open-source graphics debugger: https://renderdoc.org/
[4] AMD GPU PerfStudio: http://gpuopen.com/archive/gpu-perfstudio/