Flex is a growth-stage, NYC headquartered FinTech company that is creating the best rent payment experience. It’s hard to believe that it’s 2026 and paying rent on time is expensive, inflexible, and difficult. We’re here to change that! Flex enables our users to pay rent throughout the month on a schedule that better fits their finances and budget. Our mission is to empower as many renters as possible with flexibility over their most significant recurring expense. After deliberately keeping a stealth profile as we built up unprecedented investor support and an enthusiastic user base, we are looking for motivated individuals to help us keep our mission growing. Will you be a part of the team?
About the role
We are seeking a Senior Staff AI/ML Engineer to join our dynamic team and take a leading role in developing cutting-edge AI and machine learning systems that drive business growth. As a key technical contributor, you will drive the development, deployment, and scalability of machine learning models in a production environment, ensuring they deliver value and performance at scale. You will collaborate closely with data scientists, engineers, and product teams to implement state-of-the-art solutions that power our products and services through continuous innovation.
What you’ll do
- Lead the design, development, and deployment of scalable machine learning models for high-impact fintech applications, driving the full ML lifecycle—from research and data exploration to training, evaluation, deployment, and monitoring.
- Collaborate with data scientists, engineers, and product teams to translate complex business challenges into machine learning solutions that directly support product and business objectives.
- Build, maintain, and optimize robust ML systems that meet stringent performance, scalability, and reliability standards in a production environment.
- Continuously monitor and enhance model performance through experimentation, hyperparameter tuning, and iteration to ensure alignment with evolving business needs.
- Utilize distributed computing frameworks and cloud-native platforms to develop and maintain data pipelines, feature stores, model serving infrastructure, and MLOps workflows.
- Evaluate, adopt, and implement state-of-the-art AI/ML tools, frameworks, and methodologies to ensure technical excellence and a competitive advantage.
- Champion responsible AI practices by ensuring models comply with regulatory and ethical standards, with a focus on explainability, fairness, bias mitigation, and auditability.
- Stay current with emerging trends and innovations in AI, machine learning, software engineering, and scalable deployment to keep our systems on the cutting-edge.
Key qualifications
- Master’s or Ph.D. in Computer Science, Engineering, Statistics, or a related technical field.
- 6+ years of experience in machine learning, including 3+ years in senior or staff-level roles.
- Expert proficiency in Python (or similar languages) and experience with key ML libraries and frameworks such as TensorFlow, PyTorch, and scikit-learn.
- Extensive experience with cloud platforms (AWS, GCP, Azure), ML infrastructure tools (e.g., SageMaker, Vertex AI, MLflow), distributed computing (e.g., Spark, Kubernetes), and data workflow tools (e.g., Pandas, Airflow).
- Proven track record of designing, building, and deploying end-to-end ML systems at scale in a production environment.
- Strong background in performance optimization, version control, CI/CD, and managing the ML model lifecycle in real-world applications.
- Excellent analytical and problem-solving skills, with a proven ability to collaborate across cross-functional teams to deliver production-ready solutions that meet business goals.
For working locations in NY, the base salary pay range will be $209,000-$225,000
For all other states, the base salary pay range will be $188,000-203,000
Life at Flex:
We understand that it takes a diverse team of highly intelligent, curious, determined, empathetic, and self aware people to grow a successful company. Our HQ is located in New York City, but we have employees located throughout the US, Australia, Canada and South America. We are growing quickly, but deliberately, with a focus on building an inclusive culture. Our dynamic team has incredible perspectives to share, just as we know you do, and we take great pride in being an equal opportunity workplace.
We offer many employee benefits & perks. For full-time U.S based positions we offer:
- Competitive medical, dental, and vision available from Day 1
- Company equity
- 401(k) plan with company match (our company match kicks off at the beginning of 2026)
- Unlimited paid time off + 13 company paid holidays
- Parental leave
- Flex Cares Program
- Free Flex subscription
For full time non-US employees, we offer
