Data Scientist

Capitolis; San Francisco (CA); On-site; USD 120,000 - 160,000; Full time

Job summary

Middesk is seeking a hands-on engineer for a critical role in building fraud and risk systems. You'll design production systems that detect and prevent fraud using your expertise in fraud management and machine learning. The ideal candidate has over 4 years of experience in fraud or risk, strong applied machine learning knowledge, and familiarity with graph-based data approaches. This position offers the opportunity to influence data-driven systems at a growing company backed by leading investors.

Qualifications

• 4+ years of experience in fraud, risk, or trust & safety.
• Experience building and shipping production systems.
• Strong foundation in applied machine learning or data systems.
• Experience with graph or relational data approaches.

Responsibilities

• Build fraud & risk systems to detect and prevent fraud.
• Work with messy, real-world data to tackle complex issues.
• Leverage relationships in data for better risk detection.
• Improve signal & labeling with AI tools.
• Help scale infrastructure for data-driven systems.

Skills

Fraud analysis

Risk management

Machine learning application

Data systems

Graph-based approaches

Job description

About Middesk

Middesk makes it easier for businesses to work together. Since 2018, we’ve been transforming business identity verification, replacing slow, manual processes with seamless access to complete, up-to-date data. Our platform helps companies across industries confidently verify business identities, onboard customers faster, and reduce risk at every stage of the customer lifecycle.

Middesk came out of Y Combinator, is backed by Sequoia Capital and Accel Partners, and was recently named to Forbes Fintech 50 List.

The Role

We’re building AI-driven applications that simplify customer workflows, starting with business onboarding. With our proprietary identity data and deep domain expertise, we’re in a strong position to expand into a broader set of intelligent, risk-aware products.

We’re looking for a hands-on engineer to help build the foundation for these systems. This role is less about inventing new ML algorithms and more about applying the right techniques to messy, real-world problems. You’ve worked in fraud, risk, or trust domains, and you understand how bad actors behave, how data breaks, and how to still ship reliable systems anyway.

This is a highly technical, hands-on role with broad influence over how we design, build, and scale data-driven systems at Middesk.

What You’ll Do

• Build fraud & risk systems

  Design and ship production systems that detect and prevent fraud across KYB, trust & safety, and compliance workflows.

• Work with messy, real-world data

  Tackle problems with extreme class imbalance, sparse signals, evolving adversarial behavior, and limited ground truth.

• Leverage relationships in data

  Apply graph-based approaches and entity resolution techniques to uncover hidden connections and improve risk detection.

• Improve signal & labeling

  Use a mix of heuristics, weak supervision, and modern AI tools (including LLMs where appropriate) to generate better features and labels.

• Help scale our infrastructure

  Partner with engineering to build and evolve systems for feature generation, model training, and production deployment across multiple use cases.

What We’re Looking For

• 4+ years of experience in fraud, risk, or trust & safety

  You’ve worked on real-world fraud or abuse problems and understand the domain deeply.

• Experience building and shipping production systems

  You’ve deployed models or data-driven systems that power external-facing products.

• Strong foundation in applied ML or data systems

  Comfortable working on classification problems with real-world constraints like imbalanced data, sparse signals, and changing patterns.

• Experience with graph or relational data approaches

  Familiarity with knowledge graphs, network analysis, or entity linking is strongly preferred.

• Hands-on and pragmatic

  You focus on impact over perfection and know how to balance speed, accuracy, and maintainability.