Senior Software Engineer, Machine Learning (SF)

About PersonaPersona is the configurable identity platform built for businesses in a digital-first world. Verifying individuals and organizations is harder — but more important — than ever, with AI enabling fraudsters to launch sophisticated accounts at scale and regulations evolving rapidly.
We’ve built Persona to support practically every use case and industry — that’s why we’re able to serve a wide range of leading companies. For example, Coursera uses Persona to ensure the right person is earning each degree. Meanwhile, OpenAI relies on Persona to keep bad actors out, protecting one of the world’s most powerful AI platforms from large-scale abuse in a time when AI is reshaping the way we work and live.
We believe that making the internet safer and more human requires a team that reflects the diverse, global nature of the people we aim to serve. We’re growing rapidly and looking for exceptional people to join us.
About the RoleWe’re building both a product and a technology, and we always prioritize acting in a customer-centric way. In this role, you'll tackle challenging machine learning problems, as Persona's product needs are increasingly complex to balance the ever-changing compliance requirements of our customer base, ranging from small startups to Fortune 10 companies. You’ll develop and optimize machine learning models, contribute to cutting-edge research in generative AI and deepfake detection, and build seamless user experiences that will directly impact the long-term quality of the Persona product.

What you'll do at Persona

• Architect and manage embedding storage and vector search solutions (e.g., ClickHouse, Pinecone) for low-latency similarity queries.
• Build and maintain reproducible data pipelines (batch/stream) that vectorize text and images, ensuring quality checks and monitoring.
• Implement CI/CD for model artifacts and infrastructure-as-code, supporting containerized deployments on Kubernetes or serverless platforms.
• Develop and execute end-to-end model testing (unit, integration, performance) with versioning and rollback capabilities.
• Monitor model performance and infra health (accuracy drift, latency, resource usage) with alerting via Prometheus/Grafana or similar.
• Optimize query and system performance through index tuning, capacity planning, and cost-efficient resource allocation.
• Collaborate with data scientists, engineers, and customers to integrate, scale, and customize ML solutions from startup pilots to enterprise-scale events.

What you'll bring to Persona

• Product-thinker: You build machine learning solutions that maximize product value while minimizing complexity. You understand and can resolve tensions between product requirements and engineering design for large-scale ML projects.
• Innovative mindset: You go beyond implementing what is tasked and suggest new algorithms and models that help push our product forward. You are naturally curious and embrace change.
• Expertise in ML techniques: You have a strong foundation in machine learning algorithms, deep learning, and computer vision. You stay updated with the latest research and can apply it to solve real-world problems.
• Independent thinking: You learn from your mistakes quickly and know how to unblock yourself when needed. You take initiative to tackle new problems and drive them to impactful solutions.
• Collaborative spirit: Collaboration isn’t just a buzzword for you; it’s your secret to success. You leverage the diverse perspectives of your teammates and sometimes go out of your way to learn other functions to get the job done.

Nice to have

• 5+ years of experience as a machine learning engineer or in a related role
• Experience with large language models (LLMs) and natural language processing
• Proficiency in training and tuning vision models like YOLO or CLIP
• Familiarity with generative AI and deepfake detection technologies
• Experience with ML frameworks such as TensorFlow or PyTorch
• Background in computer vision, natural language processing, or related fields
• Knowledge of cloud platforms and services related to machine learning deployments

Compensation & equityThis salary range is the estimated base salary range. Base salaries are just one component of the total compensation package and are determined by a number of factors such as years of experience, expertise, qualifications and more. In addition to base salary, we offer competitive equity packages that play a big part in recognizing you for the huge impact you will have on helping us achieve our mission. Please note, the salary range is a guideline based on market data for roles located in the San Francisco Bay Area, and may vary depending on location. Salary ranges are subject to change without notice.
Benefits and perksPersona offers a wide range of thoughtful and inclusive benefits for this role, including medical, dental, and vision, 3% 401(k) contribution, unlimited PTO, quarterly mental health days, family planning benefits, professional development stipends, wellness benefits, unlimited paid time off, among others. While we believe competitive compensation and benefits are a critical aspect of you deciding to join us, we do hope you consider why our core values and culture are right for you. If you’d like to better understand what it’s like working at Persona, feel free to check out our reviews on Glassdoor.
Diversity, equity, inclusion and belongingAt Persona, we strive to put diversity and inclusion at the forefront of everything we do, reflecting our core values. Our DEIB Employee Resource Group seeks to build a diverse and inclusive team that fosters an environment where each Personerd feels empowered to bring their unique differences to work and achieve their full innovative potential. Our hope is that by fostering such an environment, we strengthen our business and relationships by putting people first.
We strive to promote a culture that celebrates diversity and inclusiveness regardless of, but not limited to, race, gender, sexual orientation, family status, religion, ethnicity, national origin, physical disability, veteran status, or age.