Iurii Uses: #Security

HTPBE? — Has This PDF Been Edited?

SaaS platform for PDF authenticity verification with a public REST API.

API key management for a public SaaS: hashing keys at rest, prefix + last-4 display, fail-closed validation, and revocation — plus the scoping, rotation, and

Gated B2B pricing in Next.js: per-account price lists, server-side access control so prices never leak to crawlers, and a deal-record data model where every

Webhook security past the signature: replay attacks, payload trust, DoS, IP allow-listing, and secret rotation — what verification does not protect.

Multi-tenant SaaS database design: shared schema with RLS, schema-per-tenant, and database-per-tenant — trade-offs, real pitfalls, and when to use each.

Vibe-coded codebase problems: duplicate auth flows, tests that assert nothing, unused dependencies, security shortcuts, schema drift — why they happen and how

JWT vs sessions vs OAuth for SaaS: token invalidation, mobile clients, refresh token rotation, and a decision matrix to pick the right auth pattern.

Agency codebase handover checklist: first 48 hours, security triage, architecture mapping, and how to write a takeover assessment. Practical guide.

Block scanner bots with Cloudflare WAF on the free plan. Exact rule for /.env, /wp-admin, /xmlrpc — with the starts_with gotcha and curl API deployment.

Migrate middleware.ts to proxy.ts in Next.js 16 without breaking auth.

Detect tampered PDFs using xref table analysis, metadata mismatches, orphaned objects, and font changes — 7 forensic markers explained with TypeScript code.