ABOUT SUBCRITICAL SYSTEMS
Subcritical Systems, Inc. is a venture-backed startup in Austin, Texas building the accelerator driven systems and the only US commercial manufacturer of accelerator cavities. What Space X did for rockets, we plan to do for accelerator cavities and commercialize across applications of power production, medical isotopes, semiconductors and waste transmutation.
We are in the process of building the Energy Amplifier, a novel nuclear fission system in which a particle accelerator drives a subcritical core, making meltdown physically impossible for clean power production. Due to its inherent safety, our system has a more streamlined licensing process. Our founding team includes successful entrepreneurs with a track record of building several multibillion dollar companies in deep-tech, and scientists who were leading U.S. national labs with deep experience in accelerator & nuclear technologies.
We are actively hiring to expand our team as we work toward licensing, regulatory submissions, and construction of our first energy amplifier. More information is available at subcritical.com.
ROLE SUMMARY
We are seeking an organized, detail-oriented HR & Operations Associate to join our growing team in a full-time, on-site role located in Austin, TX. The role will support the full employee lifecycle, including onboarding new staff, maintaining personnel records, assisting with I-9/E-Verify compliance, coordinating benefits administration and processing payroll in coordination with company systems and vendors. The HR & Operations Associate will also help ensure that internal processes are accurate, compliant, well-documented, and scalable as the company grows. This is an ideal role for someone who is highly organized and energized by helping build the operating infrastructure of an early-stage, fast-moving company. Candidates must be able to work on-site in Austin, TX. We are unable to accept candidates who require visa sponsorship at this time.
KEY RESPONSIBILITIES
- Process payroll accurately and on schedule, coordinating employee updates, approvals, and issue resolution with company systems and payroll providers.
- Coordinate onboarding for new staff, including employment paperwork, system setup, orientation scheduling, and internal communications.
- Maintain accurate, confidential personnel records and keep employee information current across company systems.
- Assist with I-9/E-Verify processes, documentation, and recordkeeping in accordance with company procedures and applicable requirements.
- Coordinate benefits enrollment, employee changes, and routine inquiries with benefits providers.
- Support employee offboarding, including documentation, benefits updates, equipment returns, and coordination of access removal.
- Document and maintain internal procedures, track recurring deadlines, and identify opportunities to improve accuracy and efficiency.
- Handle sensitive employee and business information with discretion.
- Support improvements to HR and operations systems, including data cleanup, workflow automation, and process standardization.
QUALIFICATIONS
Required
- Bachelor's degree or equivalent practical experience.
- 2+ years of experience in an HR, people operations, or office administration role.
- Familiarity with I-9/E-Verify processes and general employment compliance basics.
- Highly organized and detail oriented, comfortable managing sensitive and confidential information with discretion.
- Strong written and verbal communication skills
- Hands-on payroll processing experience (Gusto, Rippling, ADP, or similar).
Preferred
- HR experience in an engineering, manufacturing, or other technical/regulated industry.
- Familiarity with export control or work-authorization considerations in a hiring context.
BENEFITS
We offer health, dental, and vision insurance.
LOCATION & WORK POLICY
This role is fully in person in Austin, Texas. Our facility is located next to Austin Airport.