Director​/Senior Director of Accounting

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, Next Era 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

This is a rare opportunity to build and scale an accounting organization at a pivotal stage of growth.

Reporting to the VP of Finance & Corporate Controller, the Director of Accounting will be the senior operational accounting leader responsible for transforming the close process, strengthening accounting operations, enhancing audit readiness, and building the infrastructure required to support a rapidly growing business.

We’re not looking for someone to simply maintain existing processes. We’re looking for a leader who has built scalable accounting operations before and knows how to establish the rigor, accountability, and discipline required in a high-growth environment.

The ideal candidate combines strong operational accounting expertise with a passion for process improvement, automation, and team development.

Key Responsibilities

• Own the monthly and quarterly close process, ensuring accuracy, timeliness, and accountability
• Oversee general ledger activities, journal entries, accruals, reconciliations, payroll accounting, and related accounting operations
• Drive financial statement integrity and support management reporting requirements
• Partner closely with FP&A, Legal, HR, Operations, and other stakeholders across the organization

• Design and implement a more efficient and scalable close process
• Establish close calendars, ownership structures, review procedures, and reconciliation standards
• Develop variance and flux analysis frameworks that improve visibility and decision-making
• Create repeatable, auditable processes that support long-term growth

• Serve as the primary accounting partner to external auditors
• Coordinate audit activities and manage audit requests across the organization
• Strengthen internal controls, documentation, and accounting policies
• Help build a highly disciplined and audit-ready accounting environment

• Identify opportunities to leverage automation, AI tools, and technology to improve efficiency and reduce manual work
• Partner on ERP optimization and accounting systems enhancements
• Champion continuous improvement across accounting processes and workflows

• Lead, mentor, and develop a growing accounting organization
• Foster a culture of accountability, ownership, and operational excellence
• Help recruit and onboard future members of the accounting team as the company continues to scale

Qualifications

• 12+ years of progressive accounting experience
• 3+ years in a senior accounting leadership role such as Director of Accounting, Assistant Controller, or Controller
• Proven experience improving or transforming accounting and close processes
• Strong operational accounting background, including general ledger, reconciliations, accruals, and financial close management
• Experience managing external audits and coordinating cross‑functional audit activities
• Demonstrated success building processes, controls, and scalable accounting infrastructure
• Experience leading and developing accounting teams in fast‑paced environments
• Excellent communication and stakeholder management skills

• CPA certification
• Public accounting experience, ideally with a Big 4 or leading regional firm
• Experience in manufacturing, industrial technology, hardware, energy, cleantech, or other operationally complex industries
• Exposure to inventory and cost accounting environments
• Experience with Net…