Staff Machine Learning Engineer

As a Staff Machine Learning Engineer at Phantom, you will lead the technical strategy, architecture, and execution of Growth and Engagement ML initiatives. You bridge advanced machine learning and business strategy, designing systems that drive user acquisition, retention, lifetime value, and deep product engagement. You own the end-to-end lifecycle of complex ML models, mentor senior engineers, and collaborate closely with Product, Data Science, and Marketing leadership to move core business metrics.

What you'll do

• Define the long-term technical roadmap for Growth and Engagement ML systems, ensuring scalability, reliability, and measurable business impact
• Architect and deploy production-grade ML pipelines and real-time decisioning systems that power personalization, notification dispatch, and onboarding flows
• Evaluate and integrate cutting-edge ML techniques, including multi-armed bandits, reinforcement learning, LLMs for content generation, and advanced graph neural networks
• Design, train, and validate sophisticated models targeting user lifecycle stages: propensity to churn, lifetime value forecasting, next-best-action, and lookalike modeling
• Build and optimize recommendation engines and semantic search systems to surface highly relevant content, products, or features to users
• Establish robust experimentation frameworks using advanced A/B testing, causal inference, and multi-variate testing to rigorously validate model variants in production
• Partner with Product and Growth marketing teams to translate high-level business hypotheses into precise, actionable machine learning problems
• Mentor and coach senior engineers across the data and ML organizations, fostering a culture of technical excellence and continuous learning
• Advocate for ML engineering best practices, including model monitoring, feature store utilization, reproducible training pipelines, and data governance

What you bring

• 8+ years of professional experience in machine learning engineering, data science, or software engineering, with at least 3+ years in a Staff, Principal, or Tech Lead capacity
• Proven track record of building and scaling ML systems specifically within growth, marketing tech, recommendation engines, or consumer engagement domains
• Extensive experience with large-scale data processing and distributed computing
• Expert-level proficiency in Python, Scala, or Java
• Hands-on experience with ML frameworks such as PyTorch, TensorFlow, JAX, or XGBoost
• Strong experience with data and MLOps infrastructure including Spark, Flink, Kafka, Snowflake/BigQuery, Ray, Kubeflow, MLflow, or SageMaker
• Deep understanding of causal inference, uplift modeling, and robust statistical testing methodologies
• Ability to directly connect algorithmic improvements to top-line growth metrics such as MAU/DAU, conversion rates, and retention curves
• Exceptional ability to explain highly complex technical architectures and algorithmic choices to non-technical stakeholders and executives

What we offer

• Competitive salary and equity
• Comprehensive insurance covering medical, dental, and vision at 100%
• Stipend for your ideal remote setup including laptop, headphones, and any other work gear you may need
• Flexible hours and a long-standing, supportive remote environment
• Unlimited vacation
• 401(k) retirement plan
• Wellness benefit
• Daily lunch benefit

About Phantom

Phantom is a global financial app connecting tens of millions of users to open markets including perpetuals, prediction markets, tokenized assets, stablecoins, and memes. Ranked number 1 in Google Play's finance category, Phantom partners with trusted names like Hyperliquid, Stripe, Kalshi, and Visa. The company has 180 people globally on a fully remote team, backed by $150M in Series C funding from a16z, Sequoia Capital, and Paradigm.