Continuing our exploration of how vulnerabilities are identified, this episode focuses on external and community-driven methods, including penetration testing, bug bounty programs, responsible disclosure, and open-source intelligence (OSINT). Penetration testing simulates real-world attack scenarios—often with limited knowledge—to uncover exploitable weaknesses that automated scanners might miss, making it one of the most effective and insightful forms of testing. Bug bounty programs harness the collective power of ethical hackers by rewarding the discovery of flaws, while responsible disclosure ensures vendors are notified before vulnerabilities are made public. We also cover dark web monitoring and participation in threat-sharing organizations, which help organizations identify risks discovered or discussed outside their internal walls. These approaches expand visibility beyond the perimeter, offering insight into what attackers may already know or be actively targeting. Together, they form a broader, more strategic approach to staying one step ahead of compromise.