Sr. Administrative Assistant / Office Manager, Office of the CEO

Location: Boulder, CO — onsite, with occasional travel to other company facilities

Reports To: Chief of Staff 

Supports: Chief Executive Officer, with support to VPs and C-suite as needed 

Status: Full-time, Non-Exempt 

About Us 

Alta is reinventing how the world sources critical minerals — using protein-based chemistry to extract  rare earth elements and other essential materials from challenging feedstocks with unmatched  selectivity. By dramatically reducing the cost and environmental impact of mineral separation, Alta is  making it possible to unlock new sources of supply for 21st-century technologies. As global demand  accelerates, securing these materials has become one of the most urgent challenges facing U.S.  competitiveness and national security. Backed by top investors and government partners, Alta is  growing fast and hiring mission-driven scientists and engineers to help us scale our platform and  transform the future of mining. 

Role Summary 

Alta is hiring a Sr. Administrative Assistant / Office Manager to support the Office of the CEO. This role is  the operational backbone of Alta’s executive team — owning the scheduling, travel, workplace, and  coordination work that keeps a fast-moving leadership group running, and doing it well enough that  leadership stops thinking about it. 

The position exists because Alta is scaling. At 39 employees today and growing past 50 across multiple  facilities, the volume of executive administration and workplace operations has outgrown what can be  absorbed alongside strategic work. This role takes ownership of that volume so that the Office of the  CEO can focus on planning, execution, and organizational infrastructure. 

This is a high-trust, high-visibility position. The person in this role sees calendars, board logistics,  personnel information, and financial documents before almost anyone else does. Discretion is not a  preferred quality here; it is the job. 

Key Responsibilities 

Executive Scheduling & Calendar Management 

• Own calendar management for the CEO, and for VPs and C-suite leaders as needed
• Schedule and reschedule against shifting priorities, resolving conflicts without escalating each  one 
• Protect focus time and enforce meeting standards set by the Chief of Staff 
• Coordinate complex multi-party meetings across functions, facilities, and external stakeholders ● Manage the logistics of recurring leadership meetings, including room, materials distribution,  and remote access 

Travel, Expense & Vendor Administration 

• Book and manage domestic and international travel for the executive team, including itineraries  and contingency planning 
• Administer vendor relationships for office services: onboarding, invoicing, renewals, and issue  resolution 
• Maintain purchasing and supply processes across facilities within approved budgets ● Prepare and submit expense reports; track receipts, reconcile against policy, and follow through  to reimbursement 

Meeting & Communication Support 

• Assemble, format, and distribute meeting materials and agendas prepared by the Chief of Staff ● Capture notes and action items in leadership and cross-functional meetings, and route them  into the company’s tracking system 
• Follow up on outstanding action items and flag items at risk of slipping 
• Draft and distribute internal communications and announcements as directed ● Serve as a professional first point of contact for external visitors, partners, and investors 

Workplace & Office Operations 

• Own day-to-day office operations at the Boulder site: supplies, equipment, facilities requests,  and workspace readiness 
• Coordinate with building management, service providers, and IS on workplace issues ● Support the people-facing side of new site readiness alongside the SVP of Operations, including  workspace setup and supply logistics 
• Maintain office procedures and documentation so processes are repeatable rather than person dependent 

• Partner closely with the Facilities Ops Manager to stay current on building operations and maintenance activity (This role is not responsible for facilities upkeep directly, but is expected to be in the know)

People & Onboarding Coordination 

• Schedule interviews and coordinate candidate logistics with hiring managers and the external  HR partner 
• Execute new-hire onboarding logistics: workspace, equipment, access requests, first-week  scheduling, and welcome materials 
• Maintain HR and compliance documentation and personnel records, handling confidential  information with strict discretion 
• Support employee programs and recognition activities 

Events & Employee Experience 

• Plan and execute company events, team gatherings, and all-hands meetings across sites 
• Coordinate logistics for board meetings and investor visits, including catering, materials, and on site arrangements 
• Contribute to a consistent employee experience across all Alta locations

 

What Success Looks Like 

This role is evaluated on reliability and on the capacity it creates for others. Within the first year: 

• Executive scheduling runs without escalation; conflicts are resolved at this level rather than  passed upward 
• Travel and expense administration is fully owned, with reimbursements and reconciliations  current 
• Office and workplace operations run on documented, repeatable processes rather than  institutional memory 
• Onboarding logistics are complete before every new hire’s first day 
• Board and investor visit logistics execute without leadership involvement in the details 
• Executive administrative and workplace volume no longer sits with the Chief of Staff 

Growth Path 

This position is the first dedicated hire in the Office of the CEO and sits at Level 3 on the G&A Admin  track. As Alta scales past 50 employees and across multiple facilities, the scope of this role is expected to grow toward executive support for additional leaders and project coordination work, with a defined  path along the Admin track toward Executive Assistant (Level 5) and Sr. Executive Assistant (Level 6).  Strong performers may also move laterally into the Strategy & Execution track. 

Required Qualifications 

• Associate’s or Bachelor’s degree, or equivalent experience 
• Three to five years of administrative, executive support, or office operations experience, ideally  in a startup or high-growth environment 
• Demonstrated ability to manage complex calendars and competing priorities for senior  stakeholders 
• Proven discretion with confidential personnel, financial, and board information 
• Strong written and verbal communication, including with external partners and investors 
• Highly organized, with a bias toward closing loops and following through without reminders
• Drives tasks and projects to full completion, following up repeatedly and closing gaps in information, timing, or direction without being asked twice
• Comfortable working independently and confidently making judgment calls in ambiguous situations
• Proficiency with Google Workspace or Microsoft 365, video conferencing, and expense  management tools
• Availability outside standard hours as needed, including evenings or weekends for special events, VIP or investor visits, and time-sensitive requests from the CEO or President
• U.S. citizenship and valid passport required 

Preferred Qualifications 

• 3-5 years in Office Manager, Administrative Assistant, Executive Assistant, or similar role
• Associate’s or Bachelor’s Degree
• Experience supporting a C-level executive or executive team
• Experience coordinating board meetings, investor visits, or company events
• Familiarity with ATS platforms, HRIS systems, or onboarding coordination
• Experience in a multi-site organization
• Exposure to project or execution tracking tools such as Jira, Asana, or Notion Compensation & Benefits

The starting pay range for this position is $80,000-$95,000, commensurate with educational background and work experience. 

Benefits include: 

• 401(K) 
• Medical, Dental, Vision plans (or equivalent) 
• Flexible Time Off 
• Paid Parental Leave 
• Paid Sick Leave 
• Company Holidays