Founding Full Stack Staff Engineer - Frontier Cyber Security
First seen by Alion on Nov 11, 2026.
Hiring for Lean SuperIntelligence — via Flexiple, the recruiting partner on this role.
ABOUT US
Lean SuperIntelligence (LSI) is an AI lab building self-improving cybersecurity foundation models for enterprises. LSI publicly announced LSI-Offense-1 and LSI-Defense-1 on October 9, 2026, alongside the closing of its initial pre-seed financing.
LSI-Offense-1 discovers, exploits and validates vulnerabilities; LSI-Defense-1 detects, investigates and responds to threats. The models improve through an offense-defense feedback loop inside LSI Cyber World Models, simulated enterprise environments that turn attack and defense outcomes into training signals.
The models are designed for enterprise-controlled deployment, including on-premises and air-gapped environments, with customization on private enterprise data. Access is currently limited to selected design partners.
Founded by Chandra Khatri, LSI brings together foundation-model builders and security researchers. Its announced backers include investors and angels with AI and security leadership experience at OpenAI, CrowdStrike, SentinelOne, Zscaler, Commvault and Gruve AI. These affiliations do not imply corporate investment by those organizations.
Learn more: LSI website | Launch announcement | Financing and model news.
ABOUT THE ROLE
We are hiring a Founding Full Stack Staff Engineer to build the product surface of our frontier security platform, from data model and services through to the interfaces security teams work in every day.
You will own features end to end: backend services, agent-facing APIs, and the front end where findings, exploit evidence, and remediation workflows are reviewed and acted on. This is a senior individual-contributor role with broad architectural ownership and a direct line to design partners.
RESPONSIBILITIES
Own features end to end across data model, backend services, APIs, front end, telemetry, and rollout.
Build the interfaces security teams work in daily: finding triage, exploit evidence review, remediation and retest tracking, agent run inspection, and reporting.
Design backend services and APIs for scanning, agent execution, evidence storage, and integrations with code hosts, CI/CD, ticketing systems, and cloud accounts.
Build product surfaces on top of LLMs and autonomous agents, including streaming output, long-running task state, human approval steps, partial results, and graceful failure.
Turn AppSec workflows into product: finding deduplication, severity and reachability context, ownership routing, SLA tracking, and verification that fixes actually close the vulnerability.
Design schemas and pipelines for findings, agent trajectories, evidence artifacts, and audit trails.
Build multi-tenant foundations including authentication, authorization, RBAC, org and project scoping, audit logging, secrets handling, and tenant isolation.
Make agent behavior legible in the interface: what the agent did, what it proved, what it could not, and where a human needs to decide.
Own performance, reliability, latency, and cost across the stack, including inference and tool-execution cost surfaced to the user.
Set engineering standards for code review, testing, CI/CD, observability, incident response, and secure-by-default patterns, and treat our own attack surface as a first-class concern.
Prototype quickly with design partners, put working software in front of practitioners early, and decide what is ready to ship.
Partner with security researchers, agent-harness engineers, and product to move research capability into product without losing rigor.
QUALIFICATIONS
At least five years building and shipping production software, with meaningful time spent on cybersecurity products.
Strong full-stack ability: modern TypeScript and React on the front end, plus backend work in Go, Python, TypeScript, Java, or Rust.
Hands-on experience building application-security products, or closely adjacent ones such as code security, vulnerability management, attack-surface management, DevSecOps, offensive-security tooling, or SOC platforms.
Working security knowledge across common vulnerability classes, authentication and authorization, and secure design, with the ability to reason about the attack surface of what you build.
Experience designing APIs, data models, and asynchronous or long-running workflows.
Front-end craft on data-dense technical interfaces, including state management, streaming and real-time updates, and performance under large result sets.
Experience with cloud infrastructure, containers, CI/CD, and production operations.
Ability to scope ambiguous problems, make architectural decisions, and raise the bar for other engineers through code and review rather than process.
Clear technical writing and comfort working directly with security practitioners and design partners.
We value demonstrated ability over formal credentials, certifications, or a fixed number of years of experience.
PREFERRED QUALIFICATIONS
Experience building products on LLMs or agents, including tool use, streaming, evaluations, prompt and model versioning, and latency and cost tradeoffs.
Product experience in autonomous pentesting, code security, SAST/DAST/SCA, vulnerability management, CTEM, EDR/XDR, or SOC automation.
Personal offensive-security depth such as CVEs, bug-bounty findings, advanced CTF performance, or published research.
Experience integrating with GitHub or GitLab, CI systems, Jira or ServiceNow, SIEM and EDR platforms, or cloud provider APIs.
Experience meeting enterprise requirements such as SSO, SAML, SCIM, audit logging, VPC or on-premise deployment, and air-gapped installs.
Experience with real-time systems, websockets, job queues, or event-driven architectures.
Design sensibility and the ability to own the user experience for technical workflows without a dedicated designer.
Understanding of AI and agent security risks including prompt injection, tool poisoning or misuse, excessive permissions, untrusted content, and sandbox boundaries.
Open-source contributions, technical writing, or prior founding-engineer and early-stage experience.
Interview Preparation
Round 1 - https://docs.google.com/document/d/1wqWTTuXbRs7nRuT0chTlJJEutpDaJjRqClfGUIwS2d8/editusp=sharing
Round 2 - https://docs.google.com/document/d/1goGVQ3nomLj43Zwy9qpOYFrBEUuA5BfyWMJFUYHgHhw/editusp=sharing
Originally posted on: 8 Oct 2026