Senior ML Engineer - Remote, Build Core ML Infra

Primer.io; United States; Remote; USD 180,000 - 240,000; Full time

Benefits offered by this job

Fully remote

Generous learning budget

Private Medical Insurance

Home office stipend

Job summary

Primer is building the infrastructure for global payments. You will be the first Senior ML Engineer, shaping ML foundations, collaborating with engineering, data, and product to apply ML in payments.

You’ll own end-to-end ML features, productionize decisions, and mentor peers in a remote-first, highly impactful team. You’ll work with AWS/GCP/Azure, explore reinforcement learning, and help define how ML is used to improve routing and outcomes for merchants.

Qualifications

• Senior ML experience in ML engineering, data science, or applied research with real production deployments behind you (API, batch, or streaming).
• You think statistically. You can design and run experiments and A/B tests, and report results.
• Strong Python skills and hands-on experience with ML libraries such as scikit-learn, XGBoost, TensorFlow, PyTorch or Keras
• Solid grounding in modern software engineering, infrastructure and data tooling, and an understanding of the MLOps challenges across the full ML lifecycle.
• Familiarity with reinforcement learning (multi-armed or contextual bandits).
• Cloud experience — AWS preferred; GCP or Azure both fine
• Exposure to payments or e-commerce is a plus.
• Comfortable with ambiguity, you can research, develop and productionise independently.

Responsibilities

• Own the full lifecycle of ML-powered features from research to production deployment and monitoring.
• Productionise smart routing decisions across the payment flow and build ML infrastructure (versioning, CI/CD, observability).
• Partner with product, data and engineering to turn use cases into shipped outcomes.
• Take a pragmatic, impact-first approach to experimentation and model evaluation.
• Mentor engineers in ML techniques and trade-offs; promote simple, effective solutions.
• Talk to customers to validate ideas and test against real usage.
• Help set technical direction and prioritize use cases worth pursuing.
• Establish patterns and practices to make ML work reliable and repeatable at Primer.

Skills

Senior ML experience

Python programming

ML libraries

MLOps basics

Cloud platforms

Reinforcement learning

Experiment design

Education

Bachelor's degree

Tools

TensorFlow

PyTorch

scikit-learn

XGBoost

Keras

CI/CD tooling

Job description

Primer is building the infrastructure for global payments. You will be the first Senior ML Engineer, shaping ML foundations, collaborating with engineering, data, and product to apply ML in payments.

You’ll own end-to-end ML features, productionize decisions, and mentor peers in a remote-first, highly impactful team. You’ll work with AWS/GCP/Azure, explore reinforcement learning, and help define how ML is used to improve routing and outcomes for merchants.