I'm a Security Analyst and I've worked for multiple startups in the past. I've been acknowledged and rewarded by Microsoft, Intel, SAP, Oracle, Seagate, Bugcrowd, Sony etc for reporting vulnerabilities.
I've 3 years of experience in the field of Cyber Security. I generally prefer to follow Whitebox Testing because it helps in finding the security vulnerabilities which may lie on the internal application level. I'll help you set up a strong firewall as well!