Awesome profiling

General utilites

https://ebpf.io/: Revolutionary sandboxed kernel profiling technology that makes it easier to build various profiling utilities. Tons of options here in Python https://github.com/iovisor/bcc
Dtrace: Available on Solaris (includes Mac but not Ubuntu) with notable highlights prstat and mpstat. prstat is not available on Ubuntu but can be replicated with htop and ps
collectl: Full system level profiling including CPU, disk, memory and network
perf: CPU level performance counters
gprof: sampling and instrumentation aware profiling
google perf tools
Heaptrack: a heap memory profiler for linux
jemalloc: another heap memory profiler
ETW: Event tracing for windows
Mac OS instruments: Mac OS instruments for profiling based on top of Dtrace
Renderdoc: Multi platform graphics debugger for OpenGL and Vulkan
Windows Perf Analyzer: If htop could plot lines, windows only but recently added support for android
htop: Visualize utilization as bar charts or line charts, issue commands to processes

JProfiler: Java profiler for cpu, multithreading, graphical call stack visualizer
Java visual VM: Bundled with JDK

Pytorch profiler: Visual profiles of computations and data loading for PyTorch models, requires changes to code

Flame Graphs: flame graphs vs flame charts, off cpu profiling, icicle charts and more
Sampling vs Tracing: sampling based profilers are easier to use since they don't require any code change while instrumentation based profilers require code changes but are generally more informative
C++ performance tools: reddit post with tons of links

pyreverse: Get python classes and then visualize with graphviz
pdb: Use step in functionality or line by line to understand how your code works
IntelliJ UML Class diagrams