Full‑Stack Engineer II/Sr (React + Python)

Full‑Stack Engineer II/Sr (React + Python)

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 software integrates AI driven workflow, documentation, and research automation and is already used at 60+ nuclear reactors across North America. You'll ship production code operators and engineers rely on every day.

We're growing quickly, expanding our team and our Phoenix HQ. The work is consequential: what you build helps real plants run safer and smarter.

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

What you'll do

You'll own features end‑to‑end across a modern Python/React stack, with a heavy dose of reliability, data plumbing, and “meet the enterprise where it is” integration work.

• Ship production features across React (frontend) and FastAPI (backend) that power our products (e.g., CAP AI, AtomAssist).
• Design and evolve APIs and Postgres schemas for performance, correctness, and auditability (migrations, indexing/partitioning, background data corrections).
• Containerize and deploy services with Docker/Podman and Kubernetes; help tune queues/workers (Redis, RabbitMQ, Celery) for throughput, reliability and idempotency.
• Make data usable: build ingestion pipelines that prefer tabular sources (CSV/Excel/JSON) but gracefully handle the “we only have PDFs” reality - minimizing OCR, adding validation, and failing safely.
• Integrate with customer systems common in the industry (e.g., Maximo, DevonWay, Microsoft 365/Teams/OneNote).
• Own reliability: reduce noise and fix root causes identified across Sentry and Netdata; add observability, back‑pressure, retries, and circuit breakers so we never lose a record.
• Collaborate with customers: join (lightweight) customer calls with utilities to understand constraints, scope integrations, and demo new capabilities.

Reality of the role: You'll bounce between product code, schema work, a gnarly data import, a Sentry investigation, and a customer demo environment - often in the same week.

Examples of problems you might own in your first 90 days

• Build a DevonWay → CAP AI connector that ingests event data in tabular form, validates against our schemas, and supports safe reprocessing.
• Add a “simulate, then apply” workflow for CAP automations (human‑in‑the‑loop gates, dry‑run diffs, full audit trails, easy rollbacks).
• Cut a noisy Sentry class of errors by 30% by hardening a Celery task (idempotent writes, retry policy, dead‑letter queue).
• Implement license entitlements & usage reporting for a fleet customer renewal (clean server‑side enforcement plus UI visibility).
• Deliver a small Teams/OneNote POC to integrate new data streams into AtomAssist.

The stack you'll touch

• Frontend: React, JavaScript, HTML/CSS
• Backend: Python (FastAPI)
• Data/Infra: PostgreSQL, SQLite; Redis, RabbitMQ, Celery
• DevOps: Docker/Podman, Kubernetes; GitHub Actions
• Observability: Sentry, Netdata (and the dashboards you help us build)
• Quality: PyTest, Cypress
• Collab: Git/GitHub

What makes you a great fit

• Degree in CS or related field—or equivalent practical experience.
• You've shipped production React + FastAPI and can contribute independently within ~6 weeks.
• You care about correctness and safety: typed APIs, schema migrations with backfills, idempotent jobs, and tests that catch the sharp edges.
• You're comfortable with customer‑facing engineering (a quick demo, a clarifying question, a pragmatic workaround).
• Clear, direct communicator; kind reviewer; steady under pressure.

Nice to have (not required):

• AI/ML or data‑pipeline experience (prompting, retrieval, feature stores, vector search).
• Prior startup experience.
• Exposure to nuclear/utility or other safety‑critical domains (aviation, med‑device, rail, etc.).

Impact you'll have (near‑term roadmap)

• CAP AI “toward 100% automation” : design safe guardrails (review gates, audit, simulation modes).
• Data connectors : unstructured PDFs, structured feeds; resilient syncs with Maximo/DevonWay; M365 integrations.
• Performance & reliability : fewer flakes, faster jobs, clearer dashboards, calmer alerts.

Compensation & benefits

• Base salary: $125k - $150k (
• Equity: [–%] (meaningful ownership)
• Benefits: Unlimited vacation, health insurance, and more

Work model & schedule

• Full‑time, salaried
• Mon - Fri hybrid (Wed remote) expectation is ≥80% in‑office (Phoenix HQ)

How we hire (fast, respectful, practical)

1. 20‑min intro with the founder/hiring manager to trade context and assess mutual fit
2. Practical work sample (60 - 90 min; a real task in our stack)
3. Team meet + peer programing (system design + collaboration)
   We aim to move from first chat to decision quickly

Ready to apply?

If you want to apply modern AI and high‑quality software to problems that actually impact the future of clean energy, we'd love to meet you.