Simplify Logo
Replit

Replit

Cloud-based browser IDE with real-time collaboration

AI Agent Security Architect

Full-TimeUpdated on 9/16/2026
$230 - $350/wk
Senior
Foster City, CA, USA
Hybrid

About the job

Requirements
  • At least 6 years of experience in security engineering or security architecture, including at least 2 years dedicated to AI/ML security, large language model application security, or securing agentic frameworks.
  • Deep understanding of agentic architectures and protocols, including Model Context Protocol, LangChain, AutoGen, CrewAI, ReAct frameworks, and vector database technologies.
  • Hands-on expertise with indirect prompt injection, goal hijacking, tool parameter tampering, data poisoning, and context contamination.
  • Strong background applying OWASP Top 10 for LLMs and AI Agents, NIST AI Risk Management Framework, and MITRE ATLAS.
  • Proficiency in Python, Go, or TypeScript/JavaScript, with experience reviewing code and building functional security tooling or guardrails.
  • Experience authoring, maintaining, and evangelizing technical security architecture documentation.
  • Ability to communicate complex non-deterministic AI risks to technical engineers and executive stakeholders.
  • Experience contributing to an enterprise Cybersecurity Risk Register.
Responsibilities
  • Define the long-term vision and architectural patterns for securing autonomous agent workflows, Model Context Protocol integrations, multi-turn reasoning loops, and multi-agent coordination.
  • Architect and deploy dynamic input/output guardrail systems, semantic firewalls, and real-time intent verification filters to prevent goal hijacking, system prompt leaks, and indirect prompt injections.
  • Partner with Infrastructure and Application Security teams to design secure, short-lived, micro-isolated environments for agents to execute code, run shell commands, and interact safely with host operating systems.
  • Conduct specialized threat modeling against non-deterministic systems and lead automated and manual AI red-teaming initiatives covering retrieval-augmented generation context pipelines, vector stores, and tool-calling interfaces.
  • Architect fine-grained permission models and step-up Human-in-the-Loop authorization patterns for agents acting on behalf of users.
  • Design data isolation and poisoning prevention controls for vector databases, retrieval-augmented generation pipelines, and long-term conversation memories across multi-tenant workloads.
  • Define, document, and maintain authoritative secure design patterns and software development kits for teams building AI agent capabilities.
  • Identify, quantify, and document non-deterministic and agentic security risks for the Cybersecurity Risk Register.
  • Design tamper-evident logging and telemetry standards for agent reasoning chains, tool execution history, and context assembly to support incident response, forensics, and governance, risk, and compliance requirements.
  • Partner with governance, risk, and compliance teams to translate AI security controls into enterprise audit documentation and support Sales with complex enterprise security inquiries regarding AI safety.
Desired Qualifications
  • Experience designing runtime sandboxing and isolation technologies such as Firecracker, gVisor, Docker, or WebAssembly for dynamic code execution environments.

About the company

Replit is a cloud-based platform for software development and deployment that lets users write, run, and share code directly in a web browser, using an online editor and IDE with real-time collaboration and project management. It runs code in the browser or the cloud and provides tools for writing, executing, and debugging, along with AI-powered coding assistance across many programming languages. Everything operates in the browser with built-in collaboration and learning features, reducing local setup and enabling teams and learners to work together. Its goal is to make coding and deploying software easier and more accessible for students, freelancers, and enterprises through a shared browser-based platform.

Company Size

501-1,000

Company Stage

Series D

Total Funding

$872.2M

Headquarters

San Francisco, California

Founded

2016

Get referred to Replit

See people who can refer or advise you

Simplify Jobs

Simplify's Take

What believers are saying

  • Replit closed a $400 million round at a $9 billion valuation in March 2026.
  • Fortune reported Free Mode launched August 19, 2026, lowering token costs for subscribers.
  • Replit expanded to London in 2026 and signed PwC, EY, Mercedes-Benz, and Trustpilot.

What critics are saying

  • Replit's July 2025 agent deleted a production database, proving catastrophic trust failure.
  • Cursor, GitHub Copilot, and Lovable compress Replit's differentiation in 2026.
  • Another agent incident would freeze enterprise procurement and accelerate churn immediately.

What makes Replit unique

  • Replit pairs browser IDE, hosting, database, and AI agent in one workflow.
  • Agent 4 and Free Mode let non-engineers ship apps without local setup.
  • Google Cloud, Microsoft Fabric, and Azure integrations give enterprise deployment distribution.

Help us improve and share your feedback! Did you find this helpful?

Benefits

Competitive salary & equity

Your choice of new equipment & software

Health, dental, & vision insurance

Autonomy at work

Flexible work hours

Learning & development stipend

Monthly health & wellness stipend

Generous parental leave

Unlimited PTO (2 weeks minimum required)

401k matching

Commuter benefits

Expensed lunch

Yearly off-sites

Growth & Insights and Company News

Headcount

6 month growth

-2%

1 year growth

-3%

2 year growth

-17%
Tech.eu
Sep 8th, 2026
US AI coding startup Replit to hire 100 staff in London, mocks Silicon Valley 'monoculture

US AI coding startup Replit has opened its first overseas office in London, with plans to grow its team from 20 to around 100 staff by early next year. The San Francisco-based company joins other US tech firms expanding in London's King's Cross, including OpenAI and Anthropic. CEO Amjad Masad praised London's diversity compared to Silicon Valley's "monoculture", noting the capital offers exposure to artists, finance professionals and filmmakers alongside tech workers. London mayor Sadiq Khan attended the launch event. Replit specialises in AI-assisted coding tools and claims over 60 million users globally, including clients at 85 per cent of Fortune 500 companies. The firm raised $400 million in March at a $9 billion valuation, with backers including Databricks Ventures and Y Combinator.

PR Newswire
Sep 8th, 2026
Replit opens London office to double headcount and upskill 100 disadvantaged young people

Replit, the agentic creation platform with over 60 million users worldwide, has opened its first international office in London. The company, founded in 2016, celebrated the opening with London Mayor Sadiq Khan at a ribbon-cutting ceremony. The San Francisco-based firm will use London as its European operations hub. Replit plans to double its headcount and investment in the coming year. European enterprise customers already using the platform include PwC, Ernst & Young, Mercedes-Benz Group, TrustPilot and Hg. Replit announced a partnership with The Lord Mayor's Appeal charity to pilot a four-week coding course for 100 young Londoners not in education, employment or training. The programme aims to provide vital coding skills for employment opportunities.

TechBuzz AI
Sep 4th, 2026
Replit soars to $3B valuation on 53x revenue explosion to $150M

Replit has raised $250 million at a $3 billion valuation, driven by explosive revenue growth from $2.8 million to $150 million annualised in under 12 months — a 53-times increase. The AI-powered coding platform allows developers to build and deploy AI applications without infrastructure complexity. Prysm Capital led the round, with participation from Amex Ventures, Google's AI Futures Fund, Y Combinator, Craft Ventures, Andreessen Horowitz, and Coatue. Total funding now stands at around $478 million. Founded in 2016 by Amjad Masad, his brother Faris, and Haya Odeh, Replit has integrated deeply with Google Cloud whilst recently expanding to Microsoft Azure. The company's end-to-end platform approach has resonated with developers and enterprises seeking rapid AI development capabilities.

TechCrunch
Aug 24th, 2026
Replit CEO to discuss coding's AI revolution at TechCrunch Disrupt 2026

Amjad Masad, CEO and co-founder of Replit, will speak at TechCrunch Disrupt 2026 in San Francisco from 13–15 October. He will discuss the future of programming and the implications of AI-enabled development for both novice and professional coders. Replit has experienced explosive growth, with its current run-rate tracking toward significant expansion compared with just $2.8 million in reported revenue in 2024. Investors assigned the company a higher valuation earlier this year, six months after it received a $3 billion valuation. The session will explore how Replit helps users move beyond prototyping to fully developing their ideas. Masad's talk will address entrepreneurship and programming in the AI era.

Fortune
Aug 19th, 2026
Replit launches Free Mode powered by OpenAI's GPT-5.6 Luna after 80% price cut

Replit has launched Free Mode, a new feature powered by OpenAI's GPT-5.6 Luna model, following an 80% price cut on the model. The feature is available to subscribers paying $20 monthly for Core tier or $100 for Pro, allowing users to perform simpler tasks without depleting their AI token budgets. Free Mode automatically switches to more sophisticated models when needed, then reverts to Luna. The launch reflects broader industry trends of reducing AI costs as enterprises scrutinise return on investment and face competition from cheaper Chinese models. Replit president Michele Catasta said the partnership with OpenAI will yield additional joint product launches. OpenAI's Thibault Sottiaux noted the price reductions stem from operational efficiencies rather than increased computing capacity. Both companies aim to make powerful AI models accessible to users without technical backgrounds.