Lead Site Reliability Engineer

UMT•San Francisco, CA

22d

About The Position

UnitedMasters is hiring 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 build the tooling, monitoring, alerting, emergency response practices, and system designs teams depend on. A key focus is designing and stewarding agentic, AI-driven security pipelines that detect, triage, and help remediate vulnerabilities across code and infrastructure, with human-in-the-loop guardrails. This is also a coaching and consulting role: the engineer listens to teams, identifies reliability and security needs, builds solutions, and empowers peer developers to improve their systems. The role owns UnitedMasters’ AWS infrastructure and sets the long-term reliability and security strategy, balancing scalability and cost. The salary hiring range is $195,000–$240,000 for NY/CA. Compensation may vary by location and individual qualifications, experience, skillset, and internal equity. The company also offers medical, dental, and vision plans, a 401(k) with company match, and, depending on role and individual circumstances, possible bonuses and stock options.

Requirements

Senior-to-staff experience as an SRE, platform, or infrastructure engineer, with ownership of 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 and the ability to build tools and systems, not only configure them.
A coaching instinct 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 identified 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.
Serve as a senior escalation point for infrastructure and security issues, helping resolve incidents while coaching teams to handle future issues.
Own AWS infrastructure and set the long-term strategy for reliability and security, balancing scalability and cost.