If you want a quick way to see some details of your running application say as calls to the file system you can use dtruss:

Using process name:

$ sudo dtruss -d -n 'node' > /tmp/process.txt 2>&1

Using process id (pid):

$ sudo dtruss -d -p 345234 > /tmp/process.txt 2>&1

The output looks similar to this:

36734/0x22974d:     53236 stat64("/Users/peperone/application-core/node_modules/gkeypath\0", 0x7FFEEFBFAE80, 0x0)		 = 0 0
36734/0x22974d:     53243 stat64("/Users/peperone/application-core/node_modules/gkeypath.js\0", 0x7FFEEFBFADB0, 0x0)		 = -1 Err#2
36734/0x22974d:     53247 stat64("/Users/peperone/application-core/node_modules/gkeypath.json\0", 0x7FFEEFBFADB0, 0x0)		 = -1 Err#2
36734/0x22974d:     53250 stat64("/Users/peperone/application-core/node_modules/gkeypath.node\0", 0x7FFEEFBFADB0, 0x0)		 = -1 Err#2
36734/0x22974d:     53253 stat64("/Users/peperone/application-core/node_modules/gkeypath.mjs\0", 0x7FFEEFBFADB0, 0x0)		 = -1 Err#2
36734/0x22974d:     53284 open("/Users/peperone/application-core/node_modules/gkeypath/package.json\0", 0x1000000, 0x0)		 = 36 0
36734/0x22974d:     53339 close_nocancel(0x24)		 = 0 0
36734/0x22974d:     53437 stat64("/Users/peperone/application-core/node_modules/gkeypath/src/keypath\0", 0x7FFEEFBFAD80, 0x0)		 = -1 Err#2
36734/0x22974d:     53445 stat64("/Users/peperone/application-core/node_modules/gkeypath/src/keypath.js\0", 0x7FFEEFBFAD10, 0x0)		 = 0 0
36734/0x22974d:     53482 lstat64("/Users/peperone/application-core/node_modules/gkeypath\0", 0x7FFEEFBFAB50, 0x0)		 = 0 0
36734/0x22974d:     53490 lstat64("/Users/peperone/application-core/node_modules/gkeypath/src\0", 0x7FFEEFBFAB50, 0x0)		 = 0 0
36734/0x22974d:     53498 lstat64("/Users/peperone/application-core/node_modules/gkeypath/src/keypath.js\0", 0x7FFEEFBFAB50, 0x0)		 = 0 0
36734/0x22974d:     53610 open("/Users/peperone/application-core/node_modules/gkeypath/src/keypath.js\0", 0x1000000, 0x1B6)		 = 36 0