Principal Engineer, Generative AI

This is a remote position.

Why Unit21

Unit21 stops bad actors by equipping fintechs with no-code tools to model, detect, and investigate fraud & money-laundering patterns. We’re now harnessing agentic LLMs to 10× analyst productivity—and we need a Principal Engineer who can take us from R&D spikes to enterprise-grade production.

About The Role

We are looking for a Principal Engineer who can own the technical vision for GenAI across our entire product suite and guide us from R&D spikes to enterprise-grade production.

What You’Ll Be Doing:

• Own the technical vision for our GenAI platform: retrieval-augmented pipelines, vector-search, fine-tuning, and evaluation harnesses.
• Architect & ship new investigative agents that ingest terabytes of transactional & case data, reason over heterogeneous knowledge graphs, and generate fully auditable explanations.
• Lead model strategy: select OSS vs. commercial LLMs, run parameter-efficient tuning, implement safety & bias mitigations.
• Partner with Product & Compliance to translate complex AML workflows and regulatory requirements into intuitive agent toolsets.
• Stay ahead of the curve: prototype state-of-the-art techniques and assess fit for Unit21.
• Design MLOps/GPU infra for low-latency inference and predictable cost per investigation.
• Introduce robust evaluation & guard-rails: automated red-teaming, toxicity filters, PII leak detection, latency/cost dashboards.
• Mentor a senior team through design reviews, pair programming, and knowledge-sharing sessions.

What We Are Looking For

• 10+ years software/ML experience with 4+ years building deep-learning or NLP systems, including at least 2 years directly on LLM or GenAI products.
• Track record of architecting production GenAI systems at scale in the cloud (GCP/AWS)
• Deep understanding of RAG, vector DBs, prompt-engineering patterns, and evaluation metrics.
• Expert in Python with hands-on experience with PyTorch
• Demonstrated leadership as Staff+ IC or Tech-Lead Manager, guiding ≥5 engineers on ambiguous 0→1 initiatives.

Bonus

• Prior exposure to fraud-tech, payments, or AML domains.
• Published research / open-source contributions in LLM safety, retrieval, or agentic frameworks.

Compensation

The standard base pay range for this role is $250,000-350,000 Annually. This base pay range does not include variable compensation including potential commissions, bonuses or other financial or equity incentives.

Unit21 is an equal opportunity employer, we encourage all to apply, even if you do not meet each requirement above. We are building a diverse, inclusive workforce and hope you will join us!

What We Can Offer You:

• Competitive salary and pre-IPO stock options
• 100% company-paid medical, dental and vision insurance (for employee)
• Optional HSA and FSA medical reimbursement accounts
• Unlimited paid time off
• Generous leave programs for life events

• 401(K)

• Charity Matching

• Annual Learning & Development stipend
• One-time Home office set-up stipend

• Commuter Benefits

• Happy hours and team-building events
• Great office space in the San Francisco Financial District

• Fully Stocked Kitchen

• Lunch provided in SF office multiple times a week
• A great company culture with a strong emphasis on diversity, equity and inclusion

About Unit21:

Unit21 stops bad actors by leveraging data to deliver justice and safety in the world. We protect businesses against adversaries engaging in money laundering, fraud, and other sophisticated risks by offering no-code infrastructure to model, detect, and remediate suspicious activity. Our customers range from large Fortune 500 companies to high-potential, pre-launch startups. We have reported over USD $2 billion in fraud and laundered money to the US government using our software.

We are a rapidly growing Series C startup, having raised close to $100m from Google, Tiger Global, ICONIQ Capital, Jack Dorsey, Diane Greene, and other leading VCs. Our team believes deeply in fostering individual ownership, iterative product development, and empathetic communication. There are many challenging problems to solve in this industry, and a huge opportunity for our software to empower companies to define a new standard of eliminating bad behavior on their platforms.

We encourage people of all backgrounds to apply. Unit21 is committed to creating an inclusive culture, and we celebrate diversity of all kinds.