Senior GTM Finance Manager at Mimecast in Lexington, MA

Mimecast is a leading cybersecurity company transforming the way businesses manage and mitigate human risk. Its AI-powered, API-enabled connected human risk platform is purpose-built to protect organizations from the spectrum of cyber threats. Integrating cutting-edge technology with human-centric pathways, our platform enhances visibility and provides strategic insight.

More than 42,000 businesses worldwide trust Mimecast to help them keep ahead of the ever-evolving threat landscape. Founded in 2003, we serve over 42,000 customers across more than 100 countries, securing 27 million end users worldwide. Mimecast is headquartered in London with our North American HQ in Lexington, MA.

About the Role

If you're a finance professional who wants a genuine seat at the GTM table with direct C-suite and board-level visibility, this is the role. Mimecast is hiring a Senior GTM Finance Manager to serve as the strategic Finance partner to our global Marketing organization. You'll work with cutting-edge AI tools, operate in a genuinely collaborative environment, and have the opportunity to shape how investment decisions are made at one of the most respected names in cybersecurity SaaS.

Reporting to the VP, Channel and Marketing Finance within the Strategic & Operations Finance team, you'll own financial planning, reporting, and analysis for the Marketing function - partnering directly with the CMO and VP-level Marketing leaders while collaborating across Accounting, FP&A, Revenue Operations, Marketing Operations, and Data & Analytics.

What You'll Do

• Lead the monthly and quarterly financial close process for Marketing, coordinating with Accounting on accruals, journal entries, and third-party program spend.
• Own budget vs. actual (BvA) reporting across marketing program, campaigns, events, digital spend, and headcount for VP-level review each period.
• Investigate and clearly explain material variances; develop commentary that supports a coherent narrative for the CFO and executive leadership.
• Manage headcount reporting for the Marketing function, including funded headcount tracking, open requisitions, and personnel cost actuals vs. plan.
• Produce weekly expense and headcount reconciliation reporting for Finance and Marketing leaders.
• Own product-level P&L reporting as part of the close cycle, working with Revenue Operations and Accounting to ensure accurate, consistent cost and revenue reflection.
• Maintain the Marketing budget model with rolling forecasts tied to campaign activity, pipeline contribution, and spend pacing.
• Partner with Marketing Operations and Data & Analytics to elevate pipeline reporting accuracy - connecting spend and headcount to pipeline outcomes by theater.
• Develop CAC, pipeline coverage, and marketing ROI analytics in collaboration with Business Analytics; surface performance trends and risks for executive attention.
• Own Marketing financial content for QBRs and assist in preparing materials for the CFO, CMO, and Board of Directors.
• Participate in annual strategic planning for Marketing.
• Work with analysts on the team to provide support to the Marketing organization, provide coaching and mentoring to the analysts.

What You Bring

• A background in corporate finance with meaningful experience in SaaS or high-growth technology.
• Strong financial modelling capability and advanced Excel skills - you build models that are clean, scalable, and decision-ready.
• Proven experience supporting a Marketing function at a senior level.
• Solid understanding of SaaS metrics, GTM investment economics, and corporate finance fundamentals including close, BvA, and P&L management.
• Proficiency in Google Sheets, NetSuite, Salesforce, Tableau, and Claude or an equivalent AI platform.
• Experience leading or mentoring junior finance professionals; comfortable presenting to VP and CFO-level stakeholders.
• Process-oriented and collaborative - and genuinely enthusiastic about using AI to deliver better work faster.
• Bachelor's degree in Finance, Accounting, Economics, or Business; professional certification (MBA, CIMA, CFA, or FPAC) preferred.

What We Offer

• Market-competitive compensation, bonus eligibility, and equity participation.
• Generous paid time off and leave days.
• Flexible hybrid working model - minimum 2 days in office.
• Annual merit cycle with structured performance and compensation reviews.
• Access to cutting-edge AI tools and ongoing investment in your development.

The base salary range for this position is 132K - 198K plus benefits. This range represents the minimum and maximum new hire compensation for this role. The position may also be eligible for incentive plans and additional benefits, in accordance with company policy and local regulations. Our salary ranges are determined by role, level, and location with individual compensation also dependent on factors such as qualifications, experience, and skills. Final offers will reflect these considerations and may vary accordingly.

Belonging at Mimecast

Cybersecurity is a community effort. That’s why we’re committed to building an inclusive, diverse community that celebrates and welcomes everyone – unless they’re a cybercriminal, of course.

We’re proud to be an Equal Opportunity and Affirmative Action Employer, and we’d encourage you to join us whatever your background. We particularly welcome applicants from traditionally underrepresented groups.

We consider everyone equally: your race, age, religion, sexual orientation, gender identity, ability, marital status, nationality, or any other protected characteristic won’t affect your application.

If you require any adjustments or accommodations due to a disability, or any other reason that may help you in your interview process, please let us know by emailing careers@mimecast.com.

Due to certain obligations to our customers, an offer of employment will be subject to your successful completion of applicable background checks, conducted in accordance with local law.

It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment.