---
title: 'AI Security Engineer at Menlo Security'
canonical: 'https://feeny.ai/job/ai-security-engineer-menlo-security-emea-united-kingdom-9mr2e0fqrfan'
type: 'job'
last_seen: '2026-11-06'
---

# AI Security Engineer at Menlo Security

- **Company:** Menlo Security
- **Location:** EMEA / United Kingdom
- **Employment:** full-time
- **Posted:** 2026-10-30
- **Last confirmed live:** 2026-11-06
- **Apply:** https://jobs.ashbyhq.com/menlosecurity/55fe6667-9333-4705-a417-dbe9c07f12b0

## Job description

Menlo Security is the leader in Browser Security for human and agentic workforces. Our mission is to enable humans and agents to connect, communicate, and collaborate securely, without compromise. The Menlo Browser Security Platform protects organizations from cyberattacks by stopping threats across the web, documents, and email before they reach the user. With Menlo Agent Runtime Security (MARS), that protection now extends to the AI agents working alongside every employee. Menlo Security is trusted by major global businesses, including Fortune 500 companies and government agencies, to protect their most valuable asset, their data, and is backed by top-tier investors. We are looking for a Data & AI / ML Evaluation Engineer to own the data collection, mining, curation and continuous evaluation foundation for our various AI security products. High-quality models require high-quality datasets and ongoing enrichment and retraining. In this role, you will build automated data ingestion pipelines from surrogate web traffic and open sources, manage dataset curation, labeling workflows, model training and operate our benchmark and evaluation harnesses. This is a data and AI / ML software engineering role focused on building the data infrastructure that trains our proprietary Prompt Injection SLMs, Shadow-AI detection models, Malicious Macro classifiers, PII, Content Classification engines and more. Outcomes & KPIs Key Outcome(s) Owned:

- Automated, continuous generation and curation of training, evaluation, and false-positive (FP) datasets across web, file, and macro threat surfaces.
- Standardized, reproducible evaluation benchmarks that guide model improvements before deployment.
- Automated data pipeline uptime and ingestion throughput from web/file sources.
- Size, diversity, and labeling accuracy of threat dataset repositories (PI, Shadow-AI, PII, Macros).
- Mean time to ingest live false-positive/false-negative feedback into training evaluation loops.
- Accuracy and benchmark coverage across historical vs. newly trained SLMs.

## What You'll Do

- Design and operate automated data collection, mining, and web-scraping pipelines to gather threat samples from surrogate traffic and web sources.
- Build data processing, annotation, and dataset curation workflows, training and re-training various models, e.g. Prompt Injection (PI) SLMs, Shadow-AI detection models, Malicious Macro classifiers, and PII detection.
- Build mechanisms to capture false-positive (FP) samples from live user/DDR flows and represent / integrate them into model retraining pipelines.
- Develop automated benchmarking and evaluation harnesses to continuously test model detection quality, runtime performance, and accuracy against baseline models (e.g., Vertex AI).
- Build automated pipelines for model training for various models.
- Work closely with research and software engineering teams to turn raw detection telemetry into ongoing actionable model improvements.

Required:

- 2–4 years of experience in software engineering, data engineering, or automated QA/evaluation roles.
- Strong programming proficiency in Python. Adv: C++, SQL.
- Experience in model training and various ML, AI algorithms.
- Experience building data pipelines, web scrapers, or automated data processing systems.
- Familiarity with data structures, storage formats, and database configurations.
- Methodical approach to dataset labeling, validation, bug logging, and metric tracking.

Preferred / Nice to Have:

- Hands-on experience with ML evaluation frameworks, dataset curation, or annotation tools.
- Familiarity with text extraction, NLP preprocessing, or document parsing techniques.
- Understanding of cybersecurity concepts (Prompt Injection, Malicious Macros, DLP/PII).
- Basic experience with cloud storage, object stores, and basic containerization (Docker).
- Experience with AWS, GCP, Terraform, Kubernetes, and Linux.

Follow us on [LinkedIn](https://www.linkedin.com/company/menlo-security/)! Why Menlo? At Menlo, we don't settle for the status quo — in our technology or our culture. How we think and act is just as important as what we build. Our culture is defined by five core mindsets: Proactive Leadership, Straight Talk, United Impact, Elevated Talent, and Customer-Compelled. We take ownership and drive outcomes without waiting to be told. We communicate directly and seek hard truths. We break down silos and win together. We hold a high bar for ourselves and the people around us. And we treat every customer interaction as mission-critical. If you're someone who sees it, owns it, solves it, and does it — you'll thrive here. All qualified applicants will receive consideration for employment without regard to race, sex, color, religion, sexual orientation, gender identity, national origin, protected veteran status, or on the basis of disability. TO ALL AGENCIES: Please, no phone calls or emails to any employee of Menlo Security outside of the Talent organization. Menlo Security’s policy is to only accept resumes from agencies via Ashby (ATS). Agencies must have a valid services agreement executed and must have been assigned by the Talent team to a specific requisition. Any resume submitted outside of this process will be deemed the sole property of Menlo Security. In the event a candidate submitted outside of this policy is hired, no fee or payment will be paid.

## About Menlo Security

## Company Overview
- **One-liner**: Menlo Security provides a unified browser security platform that protects enterprises from internet-borne threats and data leakage for both human users and AI agents.
- **Entity Type**: Private (Series D; $250.8M total funding)
- **Headquarters**: Mountain View, California, United States
- **Founded**: 2014
- **Founders**: Amir Ben‑Efraim (co‑founder & former CEO; left Feb 2026)

## Core Business
- **Industry**: Computer and Network Security (cybersecurity)
- **Target Customers**: B2B, large enterprises, financial institutions, governments
- **Mission / Purpose**: “Enable the world to connect, communicate and collaborate securely without compromise.”

## Products & Services
- **Menlo Browser Security Platform** – The core offering, a hybrid (local + cloud) solution that secures any browser, enforces zero‑day threat prevention, file security, and data protection for both humans and AI agents. Delivered via a single control plane.
- **Menlo Secure Extension** – Local browser extension providing DLP and visibility for trusted web applications.
- **Menlo Cloud** – Cloud‑based rendering and threat elimination for high‑risk browsing sessions.
- **ConnectAI** – Bridges AI agents and workflows to legacy enterprise data without requiring API or system overhauls, enabling secure autonomous agent operations.

## Market Standing
- **Valuation / Market Cap**: Not disclosed
- **Annual Revenue**: ~$100 M (LinkedIn estimate)
- **Total Funding**: $250.8 M (Series C, D, B, Seed)
- **Notable Investors / Partners**: J.P. Morgan Asset Management (lead Series D), Sutter Hill Ventures, Osage University Partners; used by “8 of 10 of the world’s largest banks”
- **Growth Signals**: Headcount of 325 employees (+4.4% YoY), operates in 17 countries, claims protection against 90% of attacks, expanding into AI agent security, active hiring (+141.7% YoY job postings)

## Competitive Advantages
- **Hybrid Architecture**: First solution combining local browser security controls with cloud‑based threat elimination, ensuring performance and protection simultaneously.
- **Unified Human‑Agent Security**: Treats human users and AI agents as equal participants under the same policy framework – a unique approach that addresses the “Agentic Paradox.”
- **Proven Track Record**: Deep penetration in highly regulated industries; 8 of 10 largest banks rely on Menlo.

## Strategic Focus
- **Securing AI Agents**: Extending the platform to cover autonomous browser agents (e.g., Copilot, sidebar agents) that create new threat vectors. ConnectAI enables safe agent access to legacy data without modernization debt.
- **Expanding Global Footprint**: With offices in North America, Europe, Asia Pacific, and the Middle East, the company is scaling its sales and engineering teams to support international demand.
- **Continuous Innovation**: Developing unified policy, visibility, and control for the fluid nature of hybrid work, including both human and silicon users.

## Why Work Here
- **Culture & Values**: Emphasizes empathy, creativity, execution, collaboration, and alignment. Described as a “collaborative, problem‑solving” environment where employees are empowered to make a meaningful impact.
- **Work Policy**: Flexible remote work available globally; offices in Mountain View (HQ), Bracknell (UK), Bengaluru (India), Singapore, Tel‑Aviv, Tokyo, and others.
- **Perks**: Competitive stock options, comprehensive health plans, excellent PTO, mental health days, catered lunches, wellbeing initiatives (meditation, EAP), and equity‑first diversity & inclusion focus.
- **Engineering Culture**: “When something doesn’t work, we fix it, record it, and share it.” Employees are encouraged to take calculated risks, learn from failures, and define new ways of thinking for the industry.
- **Note**: CEO and co‑founder Amir Ben‑Efraim left in Feb 2026; leadership is in transition. The company continues to hire actively, with 29 open positions across engineering, sales, marketing, and support.

## Sources
1. [menlosecurity.com](https://www.menlosecurity.com/)
2. [menlosecurity.com – About](https://www.menlosecurity.com/about)
3. [menlosecurity.com – Life at Menlo](https://www.menlosecurity.com/about/life-at-menlo)
4. [LinkedIn – Menlo Security Inc.](https://www.linkedin.com/company/menlo-security)
5. [Menlo Security Jobs on Ashby](https://jobs.ashbyhq.com/menlosecurity)

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