OWASP Top 10 awareness is table stakes. Mature teams design abuse cases, automate verification, and rehearse incident response before regulators or customers force the conversation.
Shift-Left That Works
SAST in CI, dependency scanning on every PR, secret scanning in git hooks, and threat modeling for new integrations. Block merges on critical findings — with escape hatches documented, not informal.
Modern Authentication
OAuth 2.0 + PKCE for public clients, short-lived JWTs with rotation, hardware-backed keys for admin roles, and RBAC that defaults deny. Session fixation and CSRF remain relevant in 2026 — do not skip them because APIs are trendy.
Data Protection
TLS 1.3 everywhere, encryption at rest, field-level encryption for PII, audit trails for compliance, and key rotation automation. KVKK and GDPR are constraints on architecture, not legal footnotes.
Incident Readiness
Runbooks, on-call rotations, backup restore drills, and postmortems without blame. Security is a property of the system you operate — not a checkbox before launch.