Why Rein?

Rein was founded to solve one of cybersecurity's toughest challenges: understanding how AI agents and applications behave in real time.

Our technology helps AI and Application Security teams see risk as it really is. The result: faster, smarter security decisions based on what's actually happening inside your apps.

Backed by leading VCs, Rein is already trusted by companies across banking, energy, and SaaS.

The Role

We're looking for a driven, hands-on AI Security Engineer to help secure AI agents, applications, and the infrastructure around them. You'll combine application security, cloud security, and offensive testing to identify how AI-enabled systems can fail or be abused, then work with Engineering and Product to build practical defenses. This role suits someone who enjoys breaking down unfamiliar systems, writing code, and turning emerging AI risks into reliable security controls.

What You'll Do

- Threat-model AI agents and applications, including model, prompt, tool, data, identity, memory, retrieval, and third-party integration risks.
- Design and execute security testing for LLM and agentic systems, covering prompt injection, data leakage, unsafe tool use, excessive agency, authorization flaws, and abuse scenarios.
- Build prototypes, test harnesses, and automation in Python or a comparable language to evaluate AI behavior and reproduce security findings.
- Review application and cloud architectures, code, APIs, identity flows, and data pipelines; identify weaknesses and recommend secure design patterns.
- Develop guardrails, policy enforcement, detections,



and runtime controls that reduce risk without blocking useful AI behavior.
- Partner with Product and Engineering throughout the development lifecycle to define security requirements, validate mitigations, and support secure releases.
- Investigate security events involving AI systems and translate technical findings into clear, prioritized remediation guidance.
- Create reusable security guidance, technical documentation, and reference architectures for AI and application security teams.
- Track emerging AI attack techniques, research, and standards; test their practical relevance and incorporate useful findings into our product and practices.

What You Bring

- 3-5 years of experience in application security, product security, cloud security, security engineering, penetration testing, or a similar hands-on role.
- Strong software engineering or scripting capability, ideally in Python, with the ability to build tools, integrate APIs, and analyze complex application behavior.
- Strong knowledge of application security fundamentals, including authentication, authorization, API security, secrets management, common web vulnerabilities, and secure software design.
- Experience with at least one major cloud platform (AWS, Azure, or Google Cloud),



containerized environments, and cloud-native security controls.
- Practical familiarity with LLM applications, agent frameworks, RAG architectures, model APIs, and the security risks created by prompts, tools, memory, and untrusted data.
- Experience with threat modeling, security architecture reviews, code review, penetration testing, or adversarial testing, with clear and actionable reporting.
- Strong written and verbal English communication. Relevant security certifications, open-source work, research, or responsible disclosures are welcome, but practical capability matters more.

Who You Are

- Curious and adversarial - you naturally explore how systems can be misused, bypassed, or made to behave unexpectedly.
- A builder as well as a breaker - you can move from identifying a weakness to designing and validating a practical fix.
- Self-sufficient and highly motivated - you can navigate ambiguity, prioritize effectively, and own work without hand-holding.
- A strong communicator who translates novel technical risks into clear product impact and recommended action.
- Honest, direct, collaborative, and comfortable working in a fast-moving, early-stage environment.

What We Offer

- Competitive compensation, equity, and benefits.
- A remote role based in India, with close collaboration across a distributed team.
- Versatile PTO and a remote-friendly work environment.
- The opportunity to work closely with the company's leadership team and shape AI security technology in a high-growth startup.

📌 AI Security Engineer (India)
🏢 Rein Security
📍 India