Senior Machine Learning Engineer

Stackd; San Francisco (CA); On-site; USD 207,000 - 244,000; Full time

Benefits offered by this job

Health insurance

Fertility/adoption support

Flexible PTO

Job summary

Checkr is seeking an ML Engineer (P3) in San Francisco to build and ship AI-powered systems that support Checkr’s core products. You will own ML services end-to-end, from design to deployment, focusing on production-grade code, tests, and monitorability.

You will work with LLM APIs, CI/CD, and cross-functional teams to deliver fast, accurate, and scalable AI solutions that power background checks and related workflows.

Qualifications

• 6+ years building software in production environments.
• Experience with AI-native software and engineering craft.

Responsibilities

• Build and deploy ML/AI services used by product engineering teams.
• Design with LLMs and APIs; evaluate when to call an LLM or fine-tune.
• Write production code with tests, CI/CD, and robust abstractions.
• Partner with product and engineering to translate business problems into ML solutions.

Skills

Python

Production ML systems

LLM APIs

API design

CI/CD

Education

Bachelor's or Master's in CS/Math/related field

Tools

Rails

Job description

About Checkr Checkr is building the data platform to power safe and fair decisions. Over 140,000 companies and millions of people rely on Checkr for AI verification in the moments that matter most: getting a new job, a new place to live, a car ride, childcare, even a date. Customers include Uber, Pennymac, Airbnb, Doordash, and Anthropic. We’re a team that thrives on solving complex problems with innovative solutions that advance our mission. Checkr is recognized on Forbes Cloud 100 2025 List and is a Y Combinator 2024 Breakthrough Company . About the team/role We’re hiring an ML Engineer (P3) to build and ship the AI systems that power Checkr’s core products. This role sits on the ML team inside Checkr’s Data & ML organization within Engineering. Checkr runs millions of background checks a year. The ML team builds the systems that make those checks faster, more accurate, and cheaper to operate: document processing, charge classification, entity resolution, and in-product intelligence. These are production services that Product Engineering depends on daily. This is not a research role or a notebook role. You’ll own ML services end-to-end: design them, code them, deploy them, monitor them. We need someone who writes production software, builds with LLMs and APIs as first-class tools, and can tell the difference between working code and AI slop. If you’ve spent the last few years building AI-native software and you care deeply about engineering craft, we want to talk. This role sits in the central Data & ML team within the Engineering organization. You will partner daily with Product Engineering, Product, and cross-functional teams. You’ll also contribute to Checkr’s broader AI strategy, including our initiative to deploy our agentic fleet and build scalable context with our semantic layer. We are looking for someone based in San Francisco who has built ML systems in fast-moving, impact-first environments. Less process, more shipping. Less paperwork, more results. What you’ll do Build and deploy ML/AI services. Design, develop, and ship ML models and AI systems that Product Engineering teams rely on. You write the model code, the API layer, the monitoring, and the tests. Not notebooks; production services. Design with LLMs and APIs. Use LLM APIs (OpenAI, Anthropic, etc.) as building blocks in production systems. You know when to call an LLM, when to fine-tune, when to use a classical model, and when to write a rule. You think about cost, latency, and quality together. Ship production software. Write clean, well-structured code with solid OOP, proper abstractions, error handling, and tests. Your code gets reviewed by SWEs and passes. CI/CD is how you work, not something you bolt on at the end. Partner with product and engineering. Translate business problems into ML solutions. Define API contracts with product engineers. Explain your approach clearly to non-ML partners and leave the room with alignment, not confusion. Evaluate and iterate fast. Build evaluation frameworks, run experiments, and make data-driven decisions about model and system performance. Ship and iterate; don’t wait for perfect. Ship AI-powered workflows. Put AI to work on your own processes: automate pipelines, build agentic workflows, and contribute reusable skills and context to Checkr’s agentic platform. The expectation is that our teams operate AI-first. What you bring A Bachelor’s or Master’s degree in Computer Science, Mathematics, or a related technical field, or equivalent depth from experience 6+ years building software professionally, with at least 2 of those building ML systems that run in production Strong Python fluency; you write clean, testable, well-structured code with solid OOP instincts. Hands-on experience using LLM APIs in production systems: prompt engineering, structured outputs, function calling, cost management, and evaluation You’ve built and maintained APIs, worked with CI/CD pipelines, and shipped code that other engineers depend on Comfort with and enthusiasm for AI-assisted workflows; experience using LLMs, code-generation tools, or agentic systems in production or operational contexts is a strong signal You use AI tools (Copilot, Claude, etc.) to move faster, but you understand every line they produce. You can spot AI slop and you don’t ship it An A-player mindset with a strong bias for action: you raise the bar, move with urgency, stay resilient through ambiguity, and take ownership to deliver meaningful outcomes. Nice to have Experience with MLOps platforms (MLflow, SageMaker, Vertex, or similar) Background in document processing, OCR, or information extraction Experience with PySpark or large-scale data processing Ruby experience (Checkr’s platform runs on Rails) Familiarity with compliance-sensitive domains (fintech, legal tech, HR tech) Working knowledge of dbt, Snowflake, or modern ELT/data transformation tools Pay Transparency Disclosure We use geographic cost of labor as an input to develop ranges for our roles and as such, each location where we hire may have a different range. If this role is remote, we have listed the top to the bottom of the possible range, but we will specify the target range for an exact location when you are selected for a recruiting discussion. For more information on our compensation philosophy, see our website . On-target Earnings OR Base Salary range (San Francisco, CA) $207,000 — $244,000 USD What We Offer A fast-paced and collaborative environment Learning and development allowance Competitive cash and equity compensation, and opportunity for advancement 100% medical, dental, and vision coverage Up to $25K reimbursement for fertility, adoption, and parental planning services Flexible PTO policy Monthly wellness stipend At Checkr, we believe an in office work environment strengthens collaboration, drives innovation, and encourages connection. Our hub locations are Denver, CO; San Francisco, CA; Nashville, TN; and Santiago, Chile. Individuals are expected to work from the office 3+ days a week. In-office perks are provided, such as lunch five times a week, a commuter stipend, and an abundance of snacks and beverages. A relocation stipend may be available for those willing to relocate to a Checkr hub location. Equal Employment Opportunities at Checkr Checkr is committed to building the best product and company, which requires hiring talented and qualified individuals with a diverse set of perspectives and lived experiences. Checkr believes in hiring people of all backgrounds, including those whose histories are impacted by the justice system in accordance with local, state, and/or federal laws, including the San Francisco’s Fair Chance Ordinance . Applicant Privacy Policy If you are a California resident or are located in Alberta or British Columbia, our Applicant Privacy Policy applies to our collection and processing of your personal information when you apply for a role with us or otherwise participate in our recruitment process. For applicants in Massachusetts: It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. \\*Legitimate Checkr emails will always include our official domain name after the @ symbol (e.g., [e-mail] or [e-mail] ).