HR Manager

Deep Fission, Inc

2d • Hybrid

About The Position

The HR Manager role exists because the details matter and because every employee deserves an experience that's thoughtful, consistent, and human. Reporting to the Chief People Officer, the HR Manager is responsible for the core infrastructure of our People function: HR systems, onboarding, payroll coordination, benefits administration, and employee lifecycle processes. These aren't just administrative tasks. They're the touchpoints that shape how people feel about working at Deep Fission every day. This role also partners closely with recruiting to create a candidate experience and onboarding workflow that reflects the care we have for the people joining our team. It's a builder's role so best suited for someone who finds satisfaction in bringing order to complexity, enjoys working directly with people, and is comfortable creating structure in a fast-moving, evolving environment. Deep Fission's workforce includes remote employees, engineering teams, and onsite and field-based staff, and this role supports all of them. If you're someone who takes pride in getting the operational details right and understands that doing so is an act of care we'd love to meet you.

Requirements

• 5-8+ years of experience in HR operations, People Operations, or HR generalist roles
• Strong experience with HRIS platforms (Rippling preferred), including system administration and workflow automation
• Experience supporting distributed and multi-state workforces
• Proven ability to manage onboarding, employee lifecycle processes, and cross-functional coordination
• Strong attention to detail with a focus on data accuracy and process integrity
• Ability to operate independently in a fast-paced, evolving environment
• Excellent communication and problem-solving skills

Nice To Haves

• Experience in a startup or high-growth company environment, particularly during periods of scaling and increasing operational complexity
• Experience working with external vendors (e.g., payroll providers, benefits brokers, HR systems)
• Exposure to compliance and regulated environments
• Experience building or scaling HR processes from the ground up
• HR certification (e.g., SHRM-CP, PHR) or equivalent experience preferred

Responsibilities

• Own and administer Rippling as the system of record across HRIS, payroll, benefits, and time tracking
• Build and improve HR workflows, automations, and system processes from the ground up
• Ensure data accuracy and integrity while helping define and refine HR processes as the organization scales
• Serve as the primary point of contact for HR systems troubleshooting and vendor coordination
• Support employee relations matters and investigations, ensuring proper documentation and alignment with company policies and legal guidance
• Assist in responding to people-related incidents, including safety-related matters, in partnership with leadership, Legal, and external partners
• Support employment law compliance across federal, state, and local jurisdictions, partnering with Legal and leadership as needed
• Partner closely with Recruiting to transition candidates from the offer stage through onboarding
• Execute and continuously improve onboarding processes
• Coordinate cross-functionally with IT, Finance, and hiring managers to ensure a smooth employee experience
• Support offboarding processes with kindness, attention to compliance, and documentation
• Partner with Finance and external vendors to support payroll processing and changes
• Administer employee benefits, including enrollments, changes, and compliance requirements (e.g., ACA, COBRA), partnering with brokers/vendors as needed
• Provide responsive, high-quality employee support
• Support equity tracking and reporting for new hires and internal processes
• Create and document SOPs where none exist today
• Identify inefficiencies and implement practical, scalable solutions
• Bring structure and clarity to evolving processes without over-engineering
• Balance speed with accuracy in a fast-paced environment
• Partner with Finance, IT, Legal, and Recruiting to align on workflows and execution
• Support onboarding logistics, system access, and employee setup across teams
• Help bridge gaps between teams where ownership or processes are still evolving
• Partner with leadership and site teams to support safety-related processes and compliance (e.g., OSHA considerations) for onsite and field-based employees

Benefits

• We do not discriminate on the basis of race, color, creed, religion, ancestry, age, sex, marital status, national origin, disability, veteran status, or any other characteristic protected by applicable law.

What This Job Offers

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