Senior Recruiter and People Operations
People & HR, Operations
San Leandro, CA, USA
USD 110k-140k / year + Equity
About SirenOpt
SirenOpt helps manufacturers make better, safer, and more reliable micro- and nano-materials. These materials are the building blocks of critical sectors of the global economy such as batteries, computer chips, aircraft components, and power systems. But, surging material demand and growing complexity are pushing production to unprecedented scales and speeds, leaving manufacturers effectively flying blind. Small, undetected variations during production lead to wastage, lower performance, higher costs, and safety risks.
SirenOpt is changing this. Our manufacturing intelligence platform scans materials, revealing critical internal information without damaging them. Using a novel combination of cold atmospheric plasma, physics-informed machine learning, and predictive analytics, SirenOpt creates unique, real-time fingerprints that capture material signals no other method can access. These insights give manufacturers unprecedented visibility into how materials behave as they are made.
We turn hidden data into actionable intelligence to help manufacturers reduce variability and thus increase yield and performance. The technology can be deployed as a standalone tool or integrated directly into factory production lines. SirenOpt is currently deploying early versions of its platform with some of the largest industrial manufacturers in the world across North America, Europe, and Asia. Our first commercial product will be released in 2026.
Role Overview
SirenOpt is looking for an experienced Senior Recruiter to help us build and scale a high-performing team while supporting core HR operations. As the first full-time recruiter on the SirenOpt team, you will own full-cycle recruiting while contributing to key HR processes such as onboarding, employee lifecycle support, and policy implementation. The ideal candidate is hands-on, strategic, and comfortable operating in a fast-paced startup environment with a high degree of ownership.
This role offers an exciting opportunity to shape our hiring strategy and HR infrastructure from the ground up while working closely with leadership and cross-functional teams throughout the organization.
What You’ll Do
- Own full-cycle recruiting across technical and non-technical roles (sourcing, screening, coordinating interviews and on-site visits, and closing candidates)
- Partner with hiring managers to define role requirements, interview processes, and hiring strategies
- Build and maintain strong candidate pipelines for current and future critical roles
- Manage and optimize the Applicant Tracking System (ATS) and recruiting workflows, ensuring an excellent candidate experience
- Coordinate interviews, candidate communications, and offer processes
- Identify when to engage external search firms for specialized or senior roles, and manage those relationships and associated search processes
- Support onboarding and new hire orientation to ensure a smooth employee experience
- Assist with HR operations including employee records, compliance, and policy administration
- Help develop and document HR and recruiting processes, policies, and best practices
- Contribute to employer branding efforts (careers page, LinkedIn presence, events, and referrals)
What We’re Looking For
- Bachelor’s degree in Human Resources, Business Administration, or related field
- 8+ years of experience in recruiting, with exposure to HR responsibilities
- Demonstrated experience owning recruiting across a wide variety of functions including both technical and non-technical roles
- Proven ability to partner with leadership and hiring managers on workforce planning and hiring strategy
- Familiarity with processes such as onboarding, compliance, and employee lifecycle support
- Strong organizational and communication skills with attention to detail
- Startup experience is strongly preferred, including a demonstrated ability to manage multiple priorities effectively in a fast-paced environment
- Experience with ATS platforms (e.g., Greenhouse) and recruiting tools
- Exposure to HRIS systems, payroll coordination, and benefits administration
- Hands-on experience with HRIS, payroll coordination, and benefits administration; familiarity with Gusto is a strong plus
Why Join SirenOpt
- Opportunity to make a direct impact in building a growing, mission-driven company
- Work closely with leadership and influence hiring and HR strategy
- Fast-paced, collaborative startup environment with high ownership
- Exposure to cutting-edge technology in advanced manufacturing and AI
Benefits
- Equity and Salary compensation depends on experience
- Health, Dental, Vision plans provided
- 401k matching provided
- Time off: 20 days of PTO per year, plus approximately 15 paid US holidays per year