Lead Security Engineer

United States Digital Space LLC; Greater London; Hybrid; GBP 90,000 - 150,000; Full time

Benefits offered by this job

London office access

Learning budget

25 days annual leave

Job summary

United States Digital Space LLC is seeking a Lead Security Engineer to own and mature the company’s security program, protecting people, identities, devices, and the SaaS/AI tools we run the business on. You will be hands-on while shaping policies, controls, and incident response.

You’ll work across DevOps and Platform teams to secure our cloud environment (GCP preferred), implement ISO 27001 and SOC 2 controls, and defend against targeted phishing and fraud.

Qualifications

• Around 7–8 years of hands-on security experience with a focus on organisational security.
• Experience implementing SSO, MFA, and conditional access at company scale.
• Experience deploying MDM/EDR across a macOS fleet.
• Proven ability to own ISO 27001 and SOC 2 programs, policies and evidence.
• Experience defending against phishing, BEC and AI-enabled fraud.
• Strong collaboration with DevOps/Platform to secure cloud environments (GCP preferred).

Responsibilities

• Own identity and access across the company including SSO, MFA and conditional access.
• Lead device security across the macOS fleet using MDM and EDR.
• Run SaaS and AI security, review tools, guardrails and shadow IT.
• Respond to security incidents and improve detection/response processes.
• Partner with DevOps and Platform to secure cloud environments, IAM, and CSPM.
• Own ISO 27001 and SOC 2 controls end-to-end, including auditor walkthroughs.
• Lead third-party and vendor risk assessments and security questionnaires.

Skills

Identity management

SSO

MFA

EDR

MDM

Cloud security

ISO 27001

SOC 2

Threat protection

Phishing defense

Security incidents

Vendor risk

IAM

GCP

Policy writing

Runbooks

Tools

MDM

EDR

SIEM

CSPM

SAST/DAST/ Secrets tools

Job description

About us

the company is the universal data layer for AI that helps 300+ AI teams train and run models on the right data. Our platform indexes, curates, annotates, and evaluates data across the full AI lifecycle, from development through production.

Trusted by Woven by Toyota, AXA, UiPath, Zipline, and more. We're an ambitious team of 100+ working at the frontier of AI and have raised $60M in Series C funding from Wellington Management, CRV, Next47 and Y Combinator.

About the role

We're looking for a Lead Security Engineer to own and mature how the company secures its people, identities, devices, and the SaaS and AI tools we run the business on. You'll be hands-on, building and running controls yourself, while also owning the organisation security programme and acting as the go-to security expert across the company.

You'll play a key role in protecting our leadership team from targeted attacks, serve as the technical backbone of our ISO 27001 and SOC 2 programmes, and partner with our DevOps and Platform teams on cloud security. Above all, you'll help us stay safe while keeping our pace.

What you’ll do

• Own identity and access across the company, including SSO, MFA, conditional access, and automated joiner/mover/leaver processes.
• Manage our device security, keeping our macOS fleet protected through MDM and EDR.
• Run SaaS and AI security: discovering shadow IT, reviewing app permissions, assessing new tools before adoption, and setting sensible guardrails for how AI tools are used.
• Protect our executives and high-risk users from targeted phishing, impersonation, business email compromise, and AI-enabled fraud such as deepfakes.
• Act as the technical owner of our ISO 27001 and SOC 2 controls, from policies and evidence through to auditor walkthroughs.
• Lead third-party and vendor risk assessments.
• Respond to and lead security incidents, and continuously improve how we detect and handle them.
• Partner with DevOps and Platform to secure our cloud environment.
• Write clear policies and runbooks, and roll out changes in a way that keeps the employee experience smooth.

What you’ll bring

• Around 7-8 years of hands‑on security experience, with a strong focus on organisation security.
• Experience rolling out or re‑architecting SSO, MFA, and conditional access across a company.
• Experience deploying and managing MDM and EDR across a macOS fleet.
• A track record of building automated joiner/mover/leaver flows and user access reviews.
• Experience running SaaS security, including discovering shadow IT, reviewing app permissions, and assessing new tools before adoption.
• Experience putting guardrails around AI tool usage, such as approved tool lists, data handling rules, and vendor reviews of AI providers.
• Ownership of, or significant contribution to, ISO 27001 and/or SOC 2 audits, including policies, control evidence, and auditor walkthroughs.
• Experience defending against targeted phishing ("whaling") and business email compromise, such as fake CEO payment requests, invoice fraud, and gift card scams.
• Experience leading or supporting security incidents such as phishing compromises, account takeovers, or lost devices.
• Experience running third‑party and vendor risk assessments and advising on the security of new tools before they're adopted.
• Experience partnering with DevOps/Platform teams to secure cloud environments (ideally GCP), including IAM, network segmentation, secrets management, logging, and CSPM.
• A habit of writing policies and runbooks that people can easily follow.
• A thoughtful approach to change: you've rolled out new controls with clear communication, phased approaches, and a focus on keeping the employee experience smooth.

Nice to have

• Experience with Infrastructure-as-Code (e.g. Terraform).
• Experience owning vulnerability management across infrastructure, including scanning, prioritisation, remediation tracking, and SLAs.
• Experience building and improving detection and monitoring, centralising logs into a SIEM and defining meaningful alerts.
• Experience implementing and tuning SAST, DAST, SCA, and secrets scanning in CI/CD pipelines.
• Experience coordinating external penetration tests and bug reports, and driving fixes to closure with engineering teams.
• Experience helping engineers write secure code through guidance, patterns, and lightweight training.li>
• Experience supporting sales and customer trust by answering security questionnaires and joining customer security calls.
• Familiarity with executive digital protection, such as OSINT footprint reviews, impersonation monitoring, and out-of-band verification for sensitive requests.

Why the company

• Competitive salary, commission, and meaningful equity in a high-growth startup
• Strong in-person culture - most of the team works from our London office 4+ days/week
• 25 days annual leave + UK public holidays
• Annual learning & development budget
• Travel for customer visits, events, and conferences across the UK and Europe
• Company lunches twice a week
• Monthly socials & bi-annual team offsites