Volodymyr Z.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

I’m an eWPTX-certified Cybersecurity Consultant with a Bachelor’s degree in Cybersecurity and over 10 years of hands-on experience in application security, helping organisations identify vulnerabilities across web applications, mobile apps, APIs, cloud environments, and IoT/embedded systems. I help companies identify real vulnerabilities in their systems and understand how they can be exploited, not just theoretically, but in practice. My focus is on manual, attacker-driven testing aligned with OWASP Top 10 and beyond, with clear, actionable outcomes for your team. I’ve worked with SaaS platforms, multi-tenant systems, and applications handling sensitive data, including projects aligned with HIPAA and FDA requirements. What I can help you with: * Web and API penetration testing * Mobile application testing (iOS, Android) * Network penetration testing * Cloud and backend security assessments * IoT and embedded device penetration testing * Embedded systems security audits My approach: * Manual testing, not just automated scans * Focus on real attack paths and impact * Clear communication throughout the process What you get: * Professional report with severity (CVSS), evidence, and reproduction steps * Practical remediation guidance your developers can use * Executive summary for non-technical stakeholders Technologies and platforms I have experience with (including, but not limited to): * Frontend: React, Next.js, TypeScript, Tailwind CSS * Backend: Node.js, Express, FastAPI, Laravel (PHP) * Databases: PostgreSQL, Supabase, Firebase, MongoDB * Cloud & BaaS: AWS, Supabase, Firebase, Vercel, Cloudflare * APIs: REST, GraphQL, PostgREST * Auth & Security: JWT, OAuth, RBAC, Row Level Security (RLS) * Payments: Stripe (Checkout, webhooks, subscriptions) * Mobile: Android, iOS (dynamic analysis with Frida, Objection) * Embedded & IoT: Microcontrollers, device logic analysis, firmware interaction * DevOps & Infra: Docker, CI/CD pipelines, GitHub Actions * AI integrations: RAG-based systems, prompt injection testing, data leakage analysis I’m easy to work with, responsive, and focused on delivering results that actually improve your security.