HackerOne - HackerOne provides a platform designed to streamline vulnerability coordination and bug bounty program by enlisting hackers.
HackenProof - The world trusted Bug Bounty Platform for crypto projects
Bugcrowd - Harness the largest pool of curated and ranked security researchers to run the most efficient bug bounty and penetration tests
Cybrary - Free courses in cyber security
YesWeHack - Global Bug Bounty & Vulnerability Management Platform
CYREX - Web security vulnerability assessment & penetration testing