
Vansh Devgan
Verified Expert in Engineering
Security Engineer and Developer
Delhi, India
Toptal member since October 19, 2022
Vansh is a seasoned security researcher and full-stack developer with 5+ years of experience uncovering critical vulnerabilities for top firms like Microsoft, Google, and NordVPN. He specializes in web, cloud, and AI/ML security, including red teaming and adversarial testing. With a strong background in scripting and automation, Vansh helps companies stay ahead of modern threats.
Portfolio
Experience
- Burp Suite - 5 years
- Kali Linux - 5 years
- Node.js - 5 years
- MERN Stack - 5 years
- Source Code Review - 5 years
- Penetration Testing - 5 years
- Web App Security - 5 years
- Python 3 - 5 years
Preferred Environment
Ubuntu Linux, Burp Suite, Metasploit, NMap, Kali Linux, Amazon Web Services (AWS), Security Testing, Kubernetes, Information Security, Vulnerability Scanning
The most amazing...
...vulnerability I've found is in the Microsoft Edge browser, for which I got rewarded with a bounty of $20,000.
Work Experience
Application Security Expert
Talvaro GMBH
- Collaborated with Talvaro to review their source code and assist in developing secure coding practices for their clients.
- Assisted Talvaro in identifying critical SQL injection vulnerabilities in their code, enabling them to remediate the issues before deploying the application to their client.
- Provided key recommendations to protect the website against injection attacks such as XSS, SSTI, and SQLi, and assisted in implementing measures to prevent server-side attacks like SSRF.
- Reviewed source code for internal tools that integrated ML inference results, identifying insecure input handling that could be exploited via indirect prompt injection or manipulated vector inputs.
- Delivered secure coding recommendations to mitigate risks stemming from integrating third-party ML libraries (e.g., insecure serialization or unsanitized output used in UI rendering).
Product Security Engineer
Carousell
- Conducted source code reviews to identify security vulnerabilities early in the development lifecycle using tools like Semgrep and SonarCloud.
- Performed internal penetration testing on web, mobile, and API applications to assess and enhance security posture.
- Developed automation scripts to monitor web application attack surfaces and integrated security solutions into CI/CD pipelines.
- Set up and managed Wazuh and Nessus for continuous security monitoring, automating bi-weekly scans.
- Led threat modeling exercises across multiple products, mapping attack surfaces and improving security resilience.
- Evaluated and secured cloud infrastructure, ensuring compliance with best practices and regulatory requirements.
- Implemented PII Detection checks to prevent sensitive data leakage through APIs.
- Delivered secure code training to development teams, reducing security risks during development.
- Performed architecture reviews and threat modeling for various applications, identifying potential vulnerabilities and recommending mitigations.
- Conducted secure code reviews for Carousell’s recommendation and fraud detection ML pipelines, identifying weak points in the ML lifecycle, including artifact storage, feature engineering logic, and model access control.
Senior Product Security Engineer
Crypto.com
- Collaborated with a crypto team to manage their bug bounty program, identified issues through penetration testing in their exchange apps and decentralized finance wallet, and conducted red teaming exercises.
- Conducted source code reviews for their applications, identifying numerous issues related to hard-coded credentials, insecure server-side calls, and more.
- Worked closely with their team on various red teaming activities, uncovering information disclosure issues related to PII data, and helped them implement strong controls to secure their infrastructure.
- Led red team simulations targeting LLM-based support agents and internal automation tools, discovering input-based prompt injections and recommending role-based access for LLM endpoints based on severity classification.
- Assisted engineering teams securely integrating LLMs into consumer-facing crypto wallet features by introducing output validation, rate-limiting, and audit logging for model responses.
Product Security Engineer | Threat Modeling Expert
Yahoo!
- Contributed to the company by manually reviewing source code for their applications, offering constructive feedback for continuous improvement across the codebase.
- Aided the company in performing threat modeling for diverse new features, collaborating with the product team to enhance comprehension and prioritize potential threats.
- Assisted in coordinating dynamic penetration testing and software composition analysis (SCA) for newly introduced features and products at Yahoo.
- Designed threat models for upcoming Yahoo AI products, evaluating exposure to AI-specific attack vectors such as data poisoning, training leakage, and unauthorized model access across AWS and GCP deployments.
- Reviewed the deployment architecture for fine-tuned LLMs used in content moderation and smart reply features, helping teams implement robust guardrails for user inputs and introduce monitoring to detect model drift or misuse.
Product Security Engineer
Novelship
- Integrated multiple payment gateways into a web application and performed security assessments.
- Performed multiple security operations on assets, including source code review and internal penetration testing.
- Searched for misconfigurations in AWS and other cloud applications as part of a cloud security assessment.
- Implemented and managed single sign-on (SSO) solutions (Okta) successfully, streamlining user access and enhancing security.
Product Security Engineer
CyberXplore Pvt
- Implemented secure solutions over AWS, integrating past, DAST, and hardcoded credentials checks over GitHub.
- Collaborated closely with a small team of developers to implement new features and improve the overall security of the product.
- Conducted audits of vulnerability assessment and penetration testing (VAPT) performed by several clients and helped them build a more robust security profile and team.
- Gained significant experience detecting and fixing identity and single sign-on (SSO) issues, including those with Okta. I partnered with multiple companies to establish robust SSO solutions, enhancing their infrastructure security.
Synack Red Teamer
Synack
- Reported numerous critical vulnerabilities to clients to help secure their infrastructures.
- Assisted in verifying multiple patches for bug fixes.
- Contributed to missions to support some standard security tests requested by clients.
- Helped companies find misconfigurations in their Okta setup and helped them fix them for the proper security of their projects.
CTF Player and Bug Bounty Researcher
Self-employed
- Assisted multiple big clients, including Microsoft, Google, and Apple, to identify security issues in their web application assets, getting rewarded by them with massive bounties.
- Obtained top hacker badges at various companies on HackerOne, including NordVPN, Pluralsight, and Teachable.
- Participated in, conducted, and won many capture-the-flag (CTF) events and reached the top 15 of the national CTF event organized by Cisco SecCon CTF.
Penetration Tester
Plug&paid
- Identified multiple race condition vulnerabilities in their web application which led to financial loss to the company, and helped them with possible mitigation for the problem.
- Discovered an API leaking their AWS access key and secret key, giving an attacker complete control of their cloud infrastructure, and helped them migrate the issue, impacting their availability by 100%.
- Assisted their team with consulting on security features implementation to prevent race conditions and brute-force attacks on critical functionalities provided as a part of the web applications.
Penetration Tester
Renderforest
- Assisted as a product security engineer, helping them identify potential vulnerabilities in their web application APIs from a black-box perspective.
- Consulted their developer's team on how to write good fixes for vulnerabilities found and gave some insights about how to write secure code and always sanitize inputs.
- Helped integrate SAST and DAST into their CI/CD pipeline, working over AWS as a part of their DevSecOps.
Experience
Attack Surface Management Project
Subdomain Enumeration at Scale
Web Scraping For eCommerce Platform
Mass Vulnerability Reporting
Education
Bachelor's Degree in Computer Science
Lovely Professional University - Phagwara, India
Certifications
CREST Registered Penetration Tester (CRT)
CREST
CREST Practitioner Security Analyst (CPSA)
CREST
OffSec Certified Professional (OSCP)
OffSec
Certified Red Team Professional
Altered Security
CompTIA PenTest+
CompTIA
Skills
Libraries/APIs
Node.js, REST APIs, Google Maps, Stripe, Auth0 API, Facebook API, Facebook Ads API, Google API, React, Java Security, Gmail API, jQuery, Vue
Tools
Slack, SonarQube, AWS SDK, Checkmarx, Google Workspace, OWASP Zed Attack Proxy (ZAP), VPN, Nessus, Azure Web Application Firewall, Expo, AWS IAM, GCP Security, Metasploit, NMap, AWS ELB, Terraform, Grafana, Cisco Umbrella, Microsoft Intune, BigQuery, Loki, GitHub, Jenkins
Languages
Python 3, Python, CSS, HTML, PHP, Java, SAML, TypeScript, SQL, CSS3, HTML5, JavaScript, Bash, GraphQL, Sass, Go, Less
Frameworks
Next.js, ASP.NET, React Native, NestJS, OpenVAS, Express.js, Laravel, Jakarta Server Pages (JSP), Tailwind CSS, Cypress, Angular, .NET, ASM, Svelte
Paradigms
Penetration Testing, DevSecOps, Web Architecture, DDoS, Security Orchestration, Automation, and Response (SOAR), User Acceptance Testing (UAT), DevOps, Azure DevOps, Unit Testing, On-page SEO, Search Engine Optimization (SEO), Off-page SEO, UI Design, UX Design, HIPAA Compliance
Platforms
Windows, Burp Suite, Docker, Google Cloud Platform (GCP), Amazon Web Services (AWS), Azure, WordPress, Visual Studio Code (VS Code), Kubernetes, LAMP, Shopify, Duo, Webflow, WooCommerce, Google AppSheet, Ubuntu Linux, MacOS, Kali Linux, Heroku, Linux, Windows Server, Firebase, Ubuntu, Web, Mobile, Wazuh
Storage
PostgreSQL, MySQL, Azure Active Directory, Database Security, SQL Injection Protection, MongoDB, Docker Cloud, Amazon S3 (AWS S3), Azure Cloud Services, RDBMS, Google Cloud
Industry Expertise
Cybersecurity, Web Design
Other
MERN Stack, Ethical Hacking, Web Security, Web App Security, Application Security, IT Security, Security, ISO 27001, Security Testing, Certified Ethical Hacker (CEH), Risk Management, Software Architecture, Threat Modeling, Vulnerability Assessment, Authentication, Vulnerability Identification, APIs, SecOps, Compliance, Architecture, Security Management, Technical Writing, Security Policies & Procedures, Data Security, SOC 2, Mobile Security, System Administration, Dynamic Analysis, Cloudflare, Antivirus Software, Security Engineering, Computer Security, Security Audits, Gobuster, Rekono, SSL, HTTPS, Transport Layer Security (TLS), Managed Security Service Providers (MSSP), Information Security, Threat Intelligence, Documentation, GRC, Vulnerability Scanning, Red Teaming, Quality Assurance (QA), SAML-auth, Single Sign-on (SSO), Vulnerability Management, Shell Scripting, Web Scraping, Scraping, Data Scraping, Risk Analysis, Root-cause Analysis (RCA), Scalable Web Services, Concurrency, Encryption, Code Auditing, Kubernetes Security, Digital Forensics, Communication, Ajax, Web Hosting, Security Information and Event Management (SIEM), Audits, Information Security Management Systems (ISMS), Scanning, Calendars, PDF, Startups, OSCP, Bug Triage, Vulnerability Triage, Bug Bounty Program, Networking, CTO, Full-stack Development, Fractional CTO, Hacking, White-hat Security, White-hat Hacking, Writing & Editing, User Interface (UI), Offensive Security, IT Management, Active Directory (AD), Prometheus, Wiz Cloud Security Platform, Vulnerability Remediation, Accessibility, Performance, Wordfence Security, AI Trust, Risk and Security Management (AI TRiSM), DNS, GoDaddy, Email, Source Code Review, Employee Training, Secure Web Development, CompTIA, AWS DevOps, DevOps Engineer, Web Development, Dynamic Application Security Testing (DAST), Code Review, Consulting, Static Application Security Testing (SAST), Scripting, Risk Assessment, NIST, Containers, SSL Certificates, Data-level Security, General Data Protection Regulation (GDPR), Data Protection, Cloud Security, WAS, Security Architecture, Identity & Access Management (IAM), CI/CD Pipelines, SIEM, Intrusion Prevention Systems (IPS), Intrusion Detection Systems (IDS), JumpCloud, OAuth, Infrastructure as Code (IaC), IDS/IPS, Monitoring, OWASP, OWASP Top 10, CISO, Group Policy, Governance, IT Governance, Data Governance, Algorithms, Okta, Microsoft 365, PCI, Malware Removal, CAPTCHA, Fraud Prevention, Data Loss Prevention (DLP), Release Management, Network Engineering, IPsec, Technical SEO, Website Audits, AI Security, Artificial Intelligence (AI), App Infrastructure, Site Reliability Engineering (SRE), Data Privacy, Firewalls, Virtual Cloud Network (VCN), Firmware, Cisco, Adversarial Machine Learning, AI Risk Assessment, Large Language Model Operations (LLMOps), Machine Learning Operations (MLOps), Cyber Forensics, Customer Identity and Access Management (CIAM), Cybersecurity Maturity Model Certification (CMMC), Enterprise Cybersecurity, Cybersecurity Operations, Sprints, User Experience (UX), MDM, Cloud Infrastructure, AWS Secrets Manager, LDAP, IoT Security, Applications, Cloud, CISSP, CRTP, Laravel Forge, Business Continuity Planning (BCP), Product Security, Security Breach Consulting, Large Language Models (LLMs), Forensics, Front-end Development, Web Applications, Mobile App Security, Networks, Web & Mobile Applications, SOC 1, Autopsy, Cellebrite, EnCase
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