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Controller (Head of Accounting)

Nuclearn

Nuclearn

Accounting & Finance
Phoenix, AZ, USA
USD 145k-165k / year + Equity
Posted on Sep 21, 2025
Hands‑on, systems‑minded, and ready to build the finance backbone of a mission‑critical AI company.

Why Nuclearn.ai

Nuclearn.ai builds AI‑powered software for the nuclear and utility industries - tools that keep critical infrastructure reliable, efficient, and safe. Our platform integrates AI‑driven workflow, documentation, and research automation and is already used at 60+ nuclear reactors across North America. Fresh off a $10.5M Series A, we're hiring a player‑coach Controller to turn momentum into disciplined financial operations: clean closes, accurate invoicing, tight controls, and decision‑ready reporting.

You'll own GAAP accounting end‑to‑end, stand up order‑to‑cash with rigor (including invoicing), and scale the function as we grow.

Eligibility

U.S. citizenship or permanent residency (green card) is required due to DOE export compliance.

The role & impact

Reporting to the CFO (founder), you will lead a multi‑facet accounting organization spanning order‑to‑cash (including invoicing), procure‑to‑pay, payroll, monthly close, revenue recognition (ASC 606), audit/tax readiness, and controls that align with our SOC 2 / ISO 27001 posture. This is a working Controller role: you'll write policies, post JEs, review contracts, close the books, and build the team and systems that make it all run on rails.

You will partner cross‑functionally with Sales, Customer Success, Legal, Security, and Product to ensure contracts become correct invoices, revenue is recognized properly, and cash is predictable.

What You'll Own

Accounting ops & reporting

  • Own GAAP and the monthly close; publish a close calendar and deliver a consistent ≤ 6‑business‑day close.
  • Produce a monthly management package (P&L with product/segment views, cash flow, variance notes, KPIs).
  • Build a rolling 24‑month cash forecast and drive forecast‑to‑actual accuracy.

Order‑to‑cash & invoicing (explicitly yours)

  • Translate executed MSAs/SOWs into billing schedules by SKU (subscriptions, milestones, T&M).
  • Issue invoices on time (including utility/public‑sector portals), with correct backup and approvals.
  • Own revenue recognition policies; draft memos and JE patterns for multi‑element arrangements.
  • Manage collections (DSO targets, dunning cadence, dispute resolution) and cash application.

Procure‑to‑pay & payroll

  • Implement AP workflows (vendor onboarding, 2/3‑way approvals where needed, card/expense policies).
  • Oversee payroll and multi‑state compliance; coordinate benefits and equity accounting with HR/People.
  • Maintain clean COA, fixed assets, and capitalization thresholds.

Controls, compliance & governance

  • Stand up a lightweight internal control framework aligned to SOC 2 / ISO 27001 (change control, access, backups, audit trails).
  • Coordinate tax (federal/state income, franchise, sales/use, 1099s, nexus monitoring) with external firms.
  • Prepare PBCs and evidence for audits, security questionnaires, and enterprise customer onboarding.

Systems & data

  • Run today on QBO + modern tooling
  • Select and own tools across AP (e.g., BILL), corporate cards/expenses (e.g., Ramp/Brex), payroll/HRIS (e.g., Rippling/Gusto), equity (e.g., Carta), and close management.
  • Instrument finance KPIs (close time, on‑time invoicing, DSO, cash accuracy, error rates) and publish dashboards.

Cross‑functional & customer‑facing finance

  • Partner with Sales/Legal on deal review (pricing, billing terms, acceptance, renewals).
  • Support Customer Success on entitlement checks, usage→billing alignment, and AR escalations.
  • Contribute to security/commercial reviews (DPAs, vendor risk, SOC 2 evidence) for enterprise/utility customers.

People & org

  • Design the accounting org (Controller today; add AR/Billing Specialist and Staff/Senior Accountant as volume dictates).
  • Hire, onboard, and coach; set clear roles, growth paths, and segregation of duties.
  • Lead external partners: tax CPA, audit/review firm, and fractional support as needed.

Examples of near‑term problems you'll tackle (first 90 days)

  • Close discipline: Implement a close calendar and deliver a ≤ 6‑day close with reconciliations and no post‑close surprises.
  • Invoicing rigor: Stand up billing schedules from live contracts; standardize invoice templates and portal SOPs; clear any backlog.
  • Revenue recognition: Author policies and sample memos for subscription + services bundles; establish JE patterns and controls.
  • Cash & collections: Launch a dunning cadence; improve DSO by 10+ days; institute weekly AR reviews and cash application SLAs.
  • Controls: Lock down approvals, role‑based access, and evidence capture that satisfies SOC 2/ISO 27001 without slowing delivery.
  • Reporting: Deliver a board‑ready monthly package with product/segment views and a 24‑month runway view.
  • Org & tools: Define when to add AR/Billing and Staff Accountant; recommend pragmatic tooling (now).

You'll thrive here if you…

  • Have 6-10+ years blending public accounting (Big 4/Top 10) and startup/SaaS or services experience.
  • Are a player‑coach who can both post entries and design processes, policies, and metrics.
  • Know ASC 606 cold and have owned order‑to‑cash in enterprise/public‑sector environments (including customer portals).
  • Care about correctness and controls: typed contracts, evidence, approvals, and audit‑ready workpapers.
  • Communicate crisply with founders, customers, and auditors; write clear memos; keep calm when the numbers move.

Nice To Have (not Required)

  • CPA (active or inactive), multi‑entity consolidations.
  • SOC 2 / ISO 27001 experience; familiarity with enterprise security questionnaires.
  • Sales/use tax at multi‑state scale; revenue for milestone/T&M; light M&A integration.
  • Exposure to nuclear/utility or other regulated, safety‑critical environments.

Success Metrics (what “good” Looks Like)

  • On‑time invoicing: ≥ 98%
  • Monthly close: ≤ 6 business days (target 5 as we mature)
  • DSO: at/under contract‑weighted target; steady improvement
  • Cash forecast (13 weeks): ±5–10% accuracy
  • Billing error rate:
  • Audit/review: clean results; no material adjustments

  • Compensation & Benefits

    • Base salary: $145k - $165k
    • Equity: 0.04% - 0.12%
    • Bonus: 10%
    • Benefits: Unlimited PTO, health/dental/vision insurance

    Work model & travel

    Full‑time, salaried. Hybrid at Phoenix HQ (≥80% in‑office; Wednesdays remote). Occasional travel to customer sites, auditors, or partners as needed.

    How We Hire (fast, Respectful, Practical)

    • 20‑min CFO intro to trade context and assess mutual fit
    • Technical accounting deep dive (close, ASC 606, controls) - may include an advisor/CPA
    • Team panel (ops/systems, collections, cross‑functional collaboration)
    • Final discussion on 90‑day plan, success metrics, and board‑level reporting We move quickly from first chat to decision.

    Ready to build the accounting foundation that keeps critical infrastructure running? We'd love to meet you.