Shameless plug: although not a secure development practice, but it's a security practice to scan your application regularly. For that you should run tools like

Shameless plug: although not a secure development practice, but it's a security practice to scan your application regularly. For that you should run tools like "brakeman" for ruby on rails, for example, but you should also run dynamic tests using a free service like https://gauntlet.io https://gauntlet.io -- and you should scan regularly because scans got updated and may find new bugs. That's a good practice.