Hardware
I'm moving to late model hardware. My workstation is a 09/2018 computer. When Intel/AMD get Spectre/Meltdown solved in hardware, I'll probably buy an even newer computer. I'll try to buy as many non-Chinese components as I can. You can get a computer assembled in the U.S. But you still get parts made in China. As soon as possible I'll buy or accept a router from Verizon that uses WPA3. I'll turn off UPnP (Universal Plug and Play) if I can. Monitor the line (passive/active taps) Put the router behind a cage/door with a security lock. Move to a more secure office environment.
Software CSS (Content Security Policy - my code was probably written before or as the levels were being thrashed out) check what's going into and coming out of Local Storage ...
Tools Kali Linux Metasploit Wireshark AIDE SELinux Security Now with Steve Gibson & Leo Laporte ... Microsoft's Enterprise Security subscription, whitelist the computer programs that can run on Windows using their signatures