Solved: Quality of engineers is really going down

🚀 Executive Summary TL;DR: Junior engineers often misdiagnose network connectivity issues, mistaking firewall or security group restrictions for general ‘network problems.’ The core solution involves understanding the Principle of Least Privilege and implementing precise firewall rules, with senior engineers providing crucial mentorship on these fundamentals. 🎯 Key Takeaways The ‘Principle of Least Privilege’ dictates that systems should deny all traffic by default, requiring explicit allow rules via firewalls (e.g., iptables, AWS Security Groups). Most ‘network’ connectivity problems between applications and databases stem from misconfigured or missing firewall/security group rules, not inherent network failures. A quick diagnostic involves temporarily opening the target port to 0.0.0.0/0 to confirm firewall blockage, but this rule must be immediately reverted due to severe security risks. The correct, production-ready solution is to create specific firewall rules, ideally using Secur