As a Security Engineer 3, you are a senior individual contributor who owns security outcomes end to end across one or more product areas. You operate with limited supervision, set the technical approach for your workstreams, and are a trusted second voice in design and architecture discussions. Beyond finding and fixing vulnerabilities, you drive security initiatives to closure across engineering teams, raise the bar on how we build securely, and mentor earlier-career engineers on the team. You will combine deep hands-on offensive and defensive skills with the judgment to prioritise what matters most for a platform operating at Meesho's scale.

What you will do :

- Security Architecture & Threat Modeling: Lead threat modeling and secure design reviews for complex, multi-service features, and partner with engineering to drive the resulting security requirements into production. Contribute security expertise to architecture discussions and help shape secure-by-default patterns that other teams adopt.

- Application & Offensive Security: Own and conduct advanced security assessments (VAPT) across web platforms, APIs, and mobile applications (iOS & Android), including the business-logic, authentication, authorization, and multi-tenancy classes of issues that automated tooling misses. Plan and run red team and purple team exercises and translate findings into durable architectural fixes, not just point remediations.

- Manual Code Review: Perform in-depth manual and automated source code reviews to identify security-critical bugs, and work with developers to eliminate whole classes of vulnerabilities at the framework or platform level.

- DevSecOps & Automation: Own the integration, tuning, and scaling of security tooling (SAST, DAST, SCA, secret scanning, container scanning) in CI/CD. Design and build custom security tooling and automation that scales security across engineering teams, and contribute to supply-chain and pipeline-hardening initiatives.

- Cloud Security: Drive security reviews and hardening of cloud-native workloads (AWS, Kubernetes/EKS, containers), covering identity and access, tenant isolation, network controls, and secrets management.

AI/LLM Security: Contribute to securing Meesho's AI-powered features and workflows, including threat modeling of LLM and RAG integrations, prompt-injection and data-leakage controls, tenant isolation for AI features, and secure patterns for AI in the SDLC.

- Vulnerability & Bug Bounty Management: Own vulnerability lifecycle and remediation tracking for your areas, and help run the self-managed bug bounty program including triage, researcher engagement, and driving fixes to closure.

- Security Metrics: Define and track security metrics (coverage, remediation SLAs, mean time to remediate) for your areas and use them to drive engineering behaviour and prioritisation.

- Security Partnership & Mentorship: Act as a security subject matter expert for developers through secure-coding guidance, code reviews, and consultations. Mentor SE1 and SE2 engineers, review their work, and help level up the team's technical depth.

- Security Culture & Compliance: Drive security culture initiatives (Security Champions, developer awareness, phishing simulations) and contribute to risk and compliance efforts such as ISO 27001 readiness, TPRM, and BCP/BIA.

What you will need :

- Experience: 5-7 years of hands-on experience in product security or application security, with a demonstrated track record of owning security workstreams end to end.

- Education: A Bachelor's or Master's degree in Computer Science, Information Security, or a related field is preferred.

Core Technical Depth :

- Proven ability to lead threat modeling sessions and drive findings into the SDLC across cross-functional teams.

- Strong proficiency performing security assessments on web applications and APIs, with deep command of the OWASP Top 10 (Web and API) and complex authentication, authorization, session management, and business-logic vulnerabilities.

- Hands-on manual source code review experience, with the ability to read and reason about code in languages such as Java, Node.js, Python, and React.

- Demonstrated experience with DevSecOps, integrating and tuning security tooling in CI/CD pipelines, and building custom security automation.

- Proficiency with cloud security on AWS or GCP, including their native security tooling, and working knowledge of Docker and Kubernetes security.

- Offensive Security: Demonstrated experience planning and executing red team or purple team exercises, and translating real-world attack paths into concrete defensive improvements.

- Mobile Security: Working knowledge of mobile application security assessments for Android and iOS, familiarity with the OWASP MASVS framework and mobile-specific vulnerabilities (insecure webview, insecure deeplink, insecure data storage, flawed cryptography), and exposure to tools such as Frida, Objection, Drozer, and MobSF.

General Skills & Acumen :

- Strong analytical and problem-solving skills, with sound judgment on risk prioritisation at scale.

- Excellent communication skills, with the ability to explain complex security issues to both technical and non-technical audiences and to influence engineering decisions without direct authority.

- Ability to mentor and uplevel earlier-career security engineers.

Bonus Points :

- Relevant certifications such as OSCP, OSWE, GWAPT, or CKS.

- Active participation in public or private bug bounty programs, published CVEs, or security research.

- Experience speaking at meetups or conferences.

- Exposure to AI/LLM security (prompt injection, RAG security, OWASP LLM Top 10) and software supply-

chain security.

- Exposure to India regulatory requirements such as the DPDP Act and CERT-In directions.