Senior Executive Assistant

About Mainspring

Mainspring Energy manufactures and delivers fuel-flexible, low-emissions local power solutions that rapidly add new capacity and deliver reliable, affordable, and sustainable electric power. The company began commercial shipments of its Mainspring Linear Generators in 2020 and today has hundreds of megawatts in advanced development and field operations for leading Fortune 500 companies, data centers, and utilities. Mainspring also partners with global energy leaders including AEP, NextEra Energy Resources, Schneider Electric, and more.

The core values that ground our work, guide our decisions, and connect us together:

• Pragmatic Optimism
• Excellence without Ego
• Proactive Collaboration

Job Overview

We are seeking a highly proactive, detail-oriented, and adaptable Senior Executive Assistant to provide high-level administrative, operational, and strategic support to members of our Executive Leadership Team. Reporting directly to the SVP, People Operations, this role will initially support the Chief Financial Officer (CFO) and General Counsel, and will expand to two additional executives.

In this role, you will act as a trusted operational partner, force multiplier, and active collaborator across the business. Operating in a fast-paced environment, you will work closely with other Executive Assistants to foster an open, aligned, and collaborative administrative network. The ideal candidate anticipates needs before they arise, exercises exceptional judgment, and manages complex schedules, travel, and confidential communications with seamless precision and diplomatic tact.

Key Responsibilities

Executive & Calendar Management

• Complex Scheduling: Manage, align, and balance complex calendars for supported executive leaders, proactively resolving scheduling conflicts and optimizing their daily time
• Meeting Preparation: Prepare detailed briefing materials, agendas, background research, and presentations ahead of leadership meetings, board discussions, and external partner interactions
• Confidential Communications: Screen and prioritize incoming requests and communications; draft professional correspondence and navigate highly sensitive or confidential inquiries with complete discretion, tact, and diplomacy

Travel & Expense Coordination

• Travel Logistics: Coordinate complex, multi-leg domestic and international travel arrangements, including flights, accommodation, ground transportation, itineraries, and travel documentation
• Expense Management: Track, compile, and reconcile monthly expense reports and credit card statements in full alignment with company finance policies

Administrative Partnership & Collaboration

• EA Network Collaboration: Partner closely with other Executive Assistants across the organization to ensure seamless cross-functional alignment, shared best practices, coverage support, and cohesive communications across all executive functions
• Operational & Project Support: Drive or assist with special administrative initiatives, leadership projects, and executive-led programs from kickoff through execution
• Cross-Functional Connection: Build strong, collaborative relationships across teams (People Ops, Finance, Legal, Operations) to keep internal workflows transparent and information moving smoothly

Qualifications & Requirements

• Experience: 7+ years of experience supporting executive leadership (C-suite, General Counsel, VP level), ideally within a fast-paced, high-growth environment
• Reporting Structure: Experience reporting into HR/People Operations while partnering across multiple senior executive stakeholders
• Work Arrangement: Ability and willingness to work a hybrid schedule (on-site [X] days/week in our [City, State] office)
• Technical Skills: Advanced proficiency in Google Workspace; experience with expense platforms (e.g., Concur, Ramp, Brex) and project management platforms (e.g., Asana, Notion)
• Communication & Discretion: Exceptional written and verbal communication skills; absolute integrity and mature judgment when handling confidential financial, legal, and personnel matters
• Collaboration & Problem-Solving: Strong team-player orientation with a track record of building positive relationships with fellow EAs, internal teams, and external stakeholders under fast-paced conditions

Preferred Qualifications

• Bachelor’s degree in Business Administration, HR, Communications, or a related field
• Experience supporting Finance and/or Legal executive functions
• Background in coordinating hybrid leadership retreats, offsites, or company-wide events