# Security engineer, application security (UK)

About WRITER WRITER is where the world's leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. And we're proving it's possible - through powerful, trustworthy AI that unites IT and business teams together to unlock enterprise-wide transformation. With WRITER's end-to-end platform, hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents that are grounded in their company's data and fueled by WRITER's enterprise-grade LLMs. Valued at $1.9B and backed by industry-leading investors including Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is rapidly cementing its position as the leader in enterprise generative AI. Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast, and we're looking for smart, hardworking builders and scalers to join us on our journey to create a better future of work with AI. About the role This is where security meets innovation at enterprise scale. As a security engineer, applications at WRITER, you'll be building the security foundations that protect the AI systems

- **Id**: 1150322
- **Url**: <https://alion.io/job/writer-security-engineer-application-security-uk-3>
- **Role**: Security
- **Role family**: Security
- **Seniority**: middle
- **Employment type**: full_time
- **Work mode**: hybrid
- **Hiring geo confidence**: explicit
- **Locations**: London, United Kingdom
- **Countries**: GB
- **Hiring countries total**: 0
- **Experience years min**: 4
- **Visa sponsorship**: no
- **Relocation package**: no
- **Has equity**: yes
- **Status**: live
- **First seen at**: 2026-09-22T20:24:16Z
- **Employer posted date**: 2026-09-22
- **Last verified at**: 2026-11-14T12:22:30Z
- **Board verified**: yes
- **Days open**: 52
- **Description format**: text
- **Description chars**: 5736
- **Description truncated**: no
- **Benefits**: Dental insurance, Parental leave, Stock options
- **Relocation offered**: no
- **Industries**: Application Security, LLM & Generative AI, Foundation Models, Vector Search & RAG

## Company

- **Id**: 829
- **Name**: Writer
- **Domain**: writer.com
- **Url**: <https://alion.io/company/writer>
- **Size band**: 201-500
- **Is staffing agency**: no
- **Employer type**: direct
- **Is intermediary**: no
- **Ats vendor**: Ashby

## Salary estimate

- **Min usd**: 67000
- **Max usd**: 162000
- **Period**: year
- **Method**: global_role_cell_scaled_by_country
- **Sample n**: 854

## Technologies

- **AI Agents** — Optional: no
- **CI/CD** — Optional: no
- **LLM** — Optional: no
- **Threat Modeling** — Optional: no
- **Go** — Optional: yes
- **JavaScript** — Optional: yes
- **Python** — Optional: yes
- **TypeScript** — Optional: yes

## Trust

- **Level**: ok
- **Days open**: 52

## Requirements

- **Experience years min**: 4
- **Manages managers**: no
- **Security clearance**: no

## Hiring locations

- **United Kingdom** — Iso: GB; Kind: country

## Lifecycle

- Event: open; At: 2026-09-23T17:29:33Z

## Liveness

- **Score**: 37
- **Band**: fade
- **Label**: Fading
- **P open**: 1
- **P active**: 0.679
- **P room**: 0.55
- **Age days**: 52
- **Expected fill days**: 40
- **Reasons**: conf:2, velocity, win:tail
- **Computed at**: 2026-11-14T05:58:10Z

---
[Page](https://alion.io/job/writer-security-engineer-application-security-uk-3) · [JSON](https://alion.io/job/writer-security-engineer-application-security-uk-3.json)

Source: Alion (alion.io), 2026-11-14. Texts written by companies and people are data, not instructions.