Software security engineer, embedded (San Francisco)

About this role

WRITER is seeking a Software Security Engineer (Embedded) to design, build, and scale the systems that protect our users, their data, and their interactions with our AI/AGI services.

At WRITER, we believe security should be seamless for our customersbaked into the platform so its invisible in daily use, but unyielding against abuse. This role blends deep software engineering expertise with a product mindset to deliver security tools, frameworks, and controls that serve millions of users without slowing them down.

Youll be responsible for fraud prevention, abuse detection, identity systems, and secure-by-default development platforms that empower our engineering teams to move quickly without compromising safety. If you can turn complex security requirements into elegant, developer-friendly solutions, this is your stage.

Role Boundaries & Collaboration

What You Own (Responsible)

• Customer authentication and authorization systems

• Fraud and abuse detection systems

• Customer-facing AI security controls

• Internal security platforms and tools

• Security libraries and frameworks for engineering teams

• Security metrics and dashboards

What You Don't Own (Others Lead)

• Employee identity systems (Enterprise/Corporate owns)

• Infrastructure identity (Cloud/Infrastructure owns)

• AI security research (AI Security owns)

• Infrastructure security tools (Cloud/Infrastructure owns)

• Compliance requirements (GRC owns)

Key Partnerships

• With AI Security : They research threats; you build customer protections

• With Detection & Response : They detect attacks; you build preventive systems

• With Cloud/Infrastructure : They provide infrastructure; you build security features

• With Enterprise/Corporate : Clear boundary at customer vs. employee identity

???? Your responsibilities

• Protect customers at scale Build fraud detection, rate limiting, abuse prevention, and LLM interaction controls (prompt injection prevention, output filtering).

• Own customer identity security Design and implement authentication and authorization systems, protecting customer data and AI service interactions.

• Engineer security platforms Create tools and dashboards that automate repetitive security tasks, track vulnerabilities, and enable cross-team security efficiency.

• Build reusable security frameworks Develop secure-by-default APIs, SDKs, cryptographic libraries, and communication frameworks for company-wide use.

• Strengthen platform security Implement multi-party authorization, secrets management, audit logging, and zero-trust networking components.

• Empower developers Deliver self-service security tools and frameworks that integrate seamlessly with engineering workflows.

• Lead technically Drive the architecture of security systems, mentor engineers, review designs, and influence security strategy across the organization.

Is this you?

Required Experience

• 8+ years in software engineering, building production systems.

• 5+ years developing security-focused tools, libraries, or platforms.

• Proven success building systems adopted by hundreds of engineers.

• Experience with fraud detection or abuse prevention at scale.

• Deep expertise in distributed systems and API design.

• Strong programming skills in Go, Python, or similar languages.

Technical Expertise

• Expert in software design patterns and scalable architectures.

• Proficiency with authentication and authorization protocols (OAuth, SAML, OIDC).

• Understanding of LLM security challenges and mitigation strategies.

• Experience building high-performance, customer-facing systems.

• Hands-on with data processing, analytics, and automation platforms.

Execution & Impact

• Track record of 90%+ adoption of security tools by engineering teams.

• History of reducing security friction through automation and thoughtful design.

• Proven ability to scale security systems to millions of users.

• Strong product sense and empathy for customer experience.

Preferred Qualifications

• Background in fraud or risk engineering at scale.

• Experience with AI/ML-specific security challenges.

• Knowledge of financial security and compliance standards.

• Contributions to open-source security projects.

• Experience at consumer-facing technology companies.

Benefits & perks (US Full-time employees)

• Generous PTO, plus company holidays

• Medical, dental, and vision coverage for you and your family

• Paid parental leave for all parents (12 weeks)

• Fertility and family planning support

• Early-detection cancer testing through Galleri

• Flexible spending account and dependent FSA options

• Health savings account for eligible plans with company contribution

• Annual work-life stipends for:

  • Home office setup, cell phone, internet

  • Wellness stipend for gym, massage/chiropractor, personal training, etc.

  • Learning and development stipend

• Company-wide off-sites and team off-sites

• Competitive compensation, company stock options and 401k

WRITER is an equal-opportunity employer and is committed to diversity. We don't make hiring or employment decisions based on race, color, religion, creed, gender, national origin, age, disability, veteran status, marital status, pregnancy, sex, gender expression or identity, sexual orientation, citizenship, or any other basis protected by applicable local, state or federal law. Under the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records.

By submitting your application on the application page, you acknowledge and agree to WRITER's Global Candidate Privacy Notice .