Senior Machine Learning Engineer

Who you are

• 6+ years of software engineering experience with a strong track record of building and maintaining production ML or data-driven systems
• Strong proficiency in Python for machine learning and data processing, with working knowledge of Go, and hands-on experience deploying low-latency models into production ranking or decisioning systems
• Experience with AWS and distributed systems, including building or operating scalable training pipelines and online inference services
• Practical experience applying LLMs to reduce model development and data labeling effort, including assisted labeling, synthetic data generation, weak supervision, or model error analysis
• Strong engineering judgment and systems mindset, with an emphasis on reliability, performance, and long-term maintainability of ranking or optimization systems
• Experience using AI-assisted development tools (e.g., GitHub Copilot, ChatGPT, or similar) to accelerate iteration while maintaining high code quality
• Ability to critically evaluate AI-generated outputs, debug complex issues, and validate correctness in production ML workflows
• Bachelor’s or Master’s degree in Computer Science, Machine Learning, or a related field, or equivalent practical experience
• Familiarity with modern AI tooling and frameworks such as AWS Bedrock, LangChain, vector databases, or similar orchestration technologies used in ML-powered decisioning systems
• Experience building and operating machine learning workflows involving large language models (LLMs), including prompt-driven systems and model-assisted pipelines
• Familiarity with orchestrating ML-driven decisions in high-throughput or low-latency environments, such as ranking, recommendation, or optimization systems
• Experience with applied machine learning for relevance, ranking, or personalization problems (e.g., feature engineering, model evaluation, or feedback loops)
• Experience working in small, fast-moving, cross-functional teams, partnering closely with product, data, and platform stakeholders

What the job involves

• AI & Data at Fetch sit at the center of how we understand our business, make decisions, and build intelligent products. The organization operates as an integrated AI & data ecosystem, spanning multiple disciplines, including data engineering, analytics engineering, machine learning, experimentation, and data platforms, all working together to turn data into durable business and customer impact
• Teams operate in complex problem spaces where requirements evolve, tradeoffs are constant, and the right answer is rarely obvious. Success depends on strong technical judgment, comfort with ambiguity, and the ability to gather context and make informed decisions while balancing quality, performance, scalability, and responsible use
• Practitioners across this org contribute hands-on to production systems, analytical foundations, and intelligent features. You will collaborate closely with product, platform, and engineering partners, help shape standards and best practices, and ensure our AI and data capabilities scale reliably as Fetch grows
• We are seeking a Senior Machine Learning Engineer II to join Fetch’s Ad Ranking team
• This role sits at the intersection of applied machine learning, data engineering, and production systems, with a focus on building and improving ranking, relevance, and optimization models that drive ad selection and delivery at scale
• You will partner closely with product, data, and platform teams to develop ML-driven decisioning systems, including feature pipelines, model training and evaluation workflows, and low-latency serving infrastructure
• This is a high-impact opportunity to influence how ads are ranked and personalized across the Fetch experience, improving advertiser performance, user engagement, and overall marketplace efficiency
• Design, build, and improve machine learning models that power ad ranking, relevance, and optimization across the Fetch platform
• Implement and iterate on active learning strategies, including data sampling, error-driven retraining, and human-in-the-loop workflows to improve ranking quality
• Leverage LLMs to reduce model development and annotation effort, including synthetic data generation, assisted labeling, weak supervision, and error analysis for ranking and relevance tasks
• Own ML experimentation, offline and online evaluation, and production inference for assigned ad ranking components
• Partner closely with product, data, and platform teams to translate advertiser and user experience gaps into measurable ML improvements
• Maintain high standards for model performance, reliability, latency, and data quality in production ranking systems
• Use AI-assisted tools to accelerate development, experimentation, debugging, and analysis while maintaining strong engineering judgment
• Designing features and validating ideas with ChatGPT & Claude sandboxes
• Leveraging AI for code generation and technical prototyping
• Using AI assistants for systems architecture diagramming and design validation

Benefits

• Equity: Hop on the rocketship and have your own stake in Fetch's success with generous equity.
• 401k Match: Fetch matches 100% of the first 4% of your 401(k) contribution.
• People Benefits: Enjoy a competitive suite of ebenfits to promote health for you and your family,. Medical, Dental, and Vision insurance. Flexible Spending Accounts & Health Savings Account, with automatic employer HSA contributions per pay period. Family forming benefit with $10k lifetime stipend.
• Pet Benefits: We know your furry friends are family, too. Pet insurance is fully covered for your first pet.
• Continuing Education: Fetch provides $10,000+/year in education reimbursement support for job-related courses or programs.
• Flexible Paid Time Off: At Fetch, you'll plan your time off as you see fit with our flexible PTO policy. On top of our flexible PTO, Fetch observes 9 paid holidays as well as a year-end-week-long break.
• Robust Leave Policies: Fetch offers generous leave time for health and personal needs, including 20 weeks of parental leave for primary caregivers and 14 weeks for secondary caregivers + $2,000 incentive to assist employees with covering the cost of childcare, clothing, diapers and much more!
• Flexible Work Environment: Experience our beautiful work spaces, or get things done from the comfort of your couch. Choose what's best for each day.