Even when developers are following secure design principles and secure coding guidelines, mistakes are made. It is therefore recommended to perform automated code vulnerability scanning using a range of tools. The reports from these tools provide guidance on where vulnerabilities are most likely to exist.
This automated tool approach should be complemented with human expert code inspections to separate the true vulnerabilities from the false-positives, and also look for false-negatives the tools may have missed such as data encryption weaknesses bespoke to your applications and the context of their usage.
Security experts can then advise on remedial actions to apply and reinforce appropriate security controls, thereby preventing vulnerabilities from being exploited by threat agents.
The outcome should be an increased level of confidence that security risks are being identified and managed, rather than ignored or improperly handled.