Payroll Specialist

About Antithesis

We provide a platform that helps engineering teams identify and resolve bugs that traditional testing approaches miss. Antithesis runs your entire system in a deterministic simulation, breaks it in every way imaginable, and hands you a root cause and a perfect reproduction — no flaky tests, no false positives, no "works on my machine". This allows engineering teams to debug faster and ship with greater confidence.

The rise of AI-generated code has made what we do more important than ever. Agents can write code faster than any human — but faster code isn't better code if it's buggy, stuck in review, or issues are slipping through the cracks undetected. The verification bottleneck is real, and it's growing. This is exactly the problem Antithesis exists to solve. We've been quietly reinventing how the world thinks about software reliability, and we're just getting started.

We're well-funded, deeply technical, and building a platform that tackles one of the most complex yet important problems in modern software engineering. If that sounds like fun to you, keep reading.

About the Role

The Payroll Specialist is a core member of a lean Finance team, responsible for accurate, timely payroll and sales compensation while keeping day-to-day operations tight and well-controlled. You’ll run recurring cycles (payroll, commissions, AP/credit cards) and also create leverage for the Controller by taking on ad hoc projects that support headcount growth, international expansion, and future system upgrades.

This is a hands-on, operator/builder role for someone who likes clean execution, simple processes, and jumping in where the business needs help most.

What You'll Do

• Run end-to-end of all payrolls each cycle, ensuring accurate, timely pay, deductions, withholdings, tax fillings and clean payroll-related JEs, reconciliations, and accruals.

• Maintain compliance with federal, state, and local payroll regulations as headcount and locations grow, and help lay the groundwork for future international payroll (e.g., via EORs or local providers).

• Own calculations for sales commissions and variable compensation, translating plans into clear, auditable logic and preparing simple statements for eligible employees.

• Administer Antithesis’s corporate credit card and expense program and support AP bill processing (coding, operations, payment scheduling, vendor and tax documentation).

• Act as a responsive point of contact for employee payroll and comp questions while upholding strong documentation and controls.

• Spot and implement process improvements across payroll, comp, and AP to reduce manual work, errors, and cycle time.

• Partner closely with People, Sales, RevOps, and Finance leadership to ensure HRIS, payroll, and GL data stay aligned and useful for decision-making.

• Take on ad hoc and growth projects that create leverage for the Controller, from tool evaluations and data clean-up to supporting new entities, countries, or compensation programs.

What We Are Looking For

You don’t need to hit every bullet; candidates tend to be strongest when they bring most of the following.

• 3–5+ years of hands-on experience in payroll, compensation operations, and/or AP, ideally in a high-growth or startup environment.

• Track record owning multi-state U.S. payroll and contributing to sales commission or other variable compensation calculations.

• Strong command of payroll fundamentals and comfort working in modern payroll/HRIS, AP, and expense tools (e.g., Gusto, Rippling, Justworks, ADP, Ramp, Brex, Bill.com, or similar).

• Proficiency with spreadsheets (Excel or Google Sheets) for building and auditing models, reconciliations, and simple analyses.

• High integrity and discretion with confidential payroll, compensation, and employee data, with strong attention to detail and follow-through.

• Clear, empathetic communicator who can explain payroll and comp topics to non-finance stakeholders and build trust with employees.

• Process- and systems-minded operator who enjoys simplifying, documenting, and improving how work gets done.

• Comfortable in a fast-changing, lean environment and motivated to pick up ad hoc projects that support Antithesis’s growth and create leverage for the Controller.

Why Join Us

• Own core payroll, comp, and AP processes that directly impact every Antithesis employee.

• Create real leverage for the Controller by taking on meaningful projects, not just transactions.

• Help build scalable people and finance infrastructure as Antithesis grows in headcount, customers, and geographies.

• Work around a technically exceptional product and team in a company that values autonomy and clear results.