Senior Machine Learning Engineer; ML Underwriting

Senior Staff Machine Learning Engineer (ML Underwriting)

Affirm is reinventing credit to make it more honest and friendly, giving consumers the flexibility to buy now and pay later without any hidden fees or compounding interest.

Join the Affim team as a Senior Staff Machine Learning Engineer and become a pivotal part of our innovative ML team. Our team is dedicated to Affim's mission of revolutionizing financial services with transparency and inclusivity at its core. We are utilizing advanced machine learning techniques to deliver responsible and accessible financial products.

• You will define and drive multi‑year, multi‑team technical strategy for machine learning across Affim, ensuring alignment with company‑wide priorities and influencing the roadmaps of partner teams and platforms.
• You will lead the design, implementation, and scaling of advanced ML systems, setting the architectural direction for complex, cross‑functional initiatives and ensuring systems remain reliable, extensible, and prepared for increasingly sophisticated modeling workloads.
• You will partner deeply with ML Platform, product, engineering, and risk leadership to shape long‑term modeling capabilities, define new opportunities for ML impact, and guide infrastructure evolution required for next‑generation ML methods.
• You will provide broad technical leadership across the ML organization, mentoring senior engineers, elevating design and code quality, and spreading ML expertise through documentation, talks, and cross‑org guidance.
• You will drive clarity and alignment on ambiguous, high‑stakes technical decisions, resolving cross‑team tensions, balancing competing priorities, and exercising judgment optimized for the broader engineering organization.
• You will champion operational and system excellence at the area level, owning the long‑term health, availability, and evolution of critical ML systems, and ensuring robust testing, monitoring, and reliability practices across teams.

• You have 10+ years of experience researching, designing, deploying, and operating large‑scale, real‑time machine learning systems, with a proven record of driving technical innovation and delivering measurable business impact. Relevant PhD can count for up to 2 YOE.
• You have experience leading end‑to‑end ML system design, from data architecture and feature pipelines to model training, evaluation, and production deployment. You use distributed frameworks such as Spark, Ray, or similar large‑scale data processing systems.
• You are proficient in Python and ML frameworks, including PyTorch and XGBoost. You are experienced with ML tooling for training orchestration, experimentation, and model monitoring, such as Kubeflow, MLflow, or equivalent internal platforms.
• You have a strong understanding of representation learning and embedding‑based modeling. You possess deep expertise in neural network‑based sequence modeling, including architectures such as Transformers, recurrent, or attention‑based models, and multi‑task learning systems. You are comfortable designing and optimizing models that learn from sequential or temporal event data at scale.
• You have deep hands‑on experience with large‑scale distributed ML infrastructure, including streaming or batch data ingestion, feature stores, feature engineering, training pipelines, model serving and inference infrastructure, monitoring, and automated retraining.
• You provide strong technical leadership: defining long‑term strategy, guiding research direction, and aligning work across teams. You are recognized as a trusted expert who can drive clarity and execution even in ambiguous problem spaces.
• You demonstrate exceptional judgment, collaboration, and communication skills, enabling effective technical discussions with engineers, researchers, and executives. You mentor senior engineers, foster technical excellence, and contribute to a culture of continuous learning.
• You have strong verbal and written communication skills that support effective collaboration across our global engineering organization.
• This position requires equivalent practical experience or a Bachelor’s degree in a related field.

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