Lead Site Reliability Engineer

UnitedMasters • San Francisco, CA

11d

About The Position

UnitedMasters is seeking a Lead Site Reliability Engineer to own the intersection of reliability and security across the organization. The role partners with platform, data, QA, and product engineers to provide the tooling, monitoring, alerting, emergency response, and systems design teams rely on. A key focus is designing and stewarding agentic, AI-driven security pipelines that continuously detect, triage, and help remediate vulnerabilities, with human-in-the-loop safeguards.

This is also a coaching and consulting role: the engineer will listen to teams, identify reliability and security needs, build solutions, and empower peer developers to improve their systems. The role owns AWS infrastructure and the long-term strategy for reliability and security, balancing scalability and cost.

Requirements

• Senior-to-staff experience as an SRE, platform, or infrastructure engineer, owning production reliability at scale.
• Hands-on application and/or infrastructure security experience sufficient to lead security discussions without a separate security team.
• Practical experience building with LLMs and agentic systems, including having shipped a real system and understanding its failure modes and where human oversight is essential.
• Strong software engineering fundamentals, with experience building tools and systems rather than only configuring them.
• A coaching mindset and a focus on raising the capabilities of surrounding teams.

Responsibilities

• Partner with platform, data, QA, and product teams to understand their automation, infrastructure, monitoring, and security needs.
• Build tooling and processes to address needs surfaced through collaboration with teams.
• Build and maintain an agentic vulnerability detection and mitigation pipeline that scans, triages, and proposes fixes with human-in-the-loop guardrails.
• Embed security into the development lifecycle through threat modeling, supply-chain hygiene, secrets management, and secure-by-default patterns.
• Lead security and reliability incident response as first-class operational concerns.
• Define company-level SLAs, SLOs, and Error Budgets, and help teams establish their own.
• Guide system design toward shared tooling and decisions that support reliability, scalability, security, and maintainability.
• Participate in the on-call rotation, identify process gaps, and coach teams on response.
• Act as a senior escalation point for infrastructure and security issues, helping resolve them while coaching teams to handle future issues.
• Own AWS infrastructure and set the long-term strategy for reliability and security, balancing scalability and cost.

Benefits

• Company-sponsored medical, dental, and vision plans.
• 401(k) with company match.
• Depending on the role and individual circumstances, additional compensation opportunities such as bonuses and stock options.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed