Principal Software Engineer, Machine Learning

Job Description: • Build and scale ML infrastructure for personalization, search, ranking, and ad tech at consumer scale. • Design and implement zero-to-one systems, including real-time learning and data pipelines. • Lead technical design, architecture, and cross-team alignment for major ML initiatives. • Mentor engineers and help raise the bar on technical execution and design quality. • Partner with product and engineering teams to create dynamic systems that adapt to evolving user preferences. • Use AI tools to accelerate work: 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; exploring LLMs to enhance personalization, conversational search, and feature creation. • Drive new initiatives, shape the technical direction of ML at Fetch, and deliver high-impact ML systems from scratch. Requirements: • Proven experience building and scaling ML infrastructure in support of personalization, relevance, search, or ad tech systems. • Deep hands-on expertise in data infrastructure, distributed systems, and large-scale data pipelines. • Experience working at a consumer product company with ML models operating at scale. • Prior contributions to ranking, personalization, or ad tech systems with measurable business impact. • Strong systems design skills, with a track record of leading architecture and communicating design tradeoffs. • Experience mentoring and elevating other engineers. • Success leading zero-to-one technical initiatives and delivering new infrastructure or ML systems from scratch. • Ability to operate in high levels of ambiguity with minimal direction, prioritizing effectively and driving impact. • Preferred: Familiarity with LLMs and their application in personalization, feature creation, and conversational search. • Preferred: Experience with streaming/real-time learning systems. • Preferred: Exposure to conversational search or large-scale information retrieval. • Preferred: Previous work bridging model development with real-time serving systems. Benefits: • Equity: We offer employees equity in Fetch, so that everyone can benefit from Fetch’s growth. • 401k Match: Dollar-for-dollar match up to 4%. • Benefits for humans and pets: We offer comprehensive medical, dental and vision plans for everyone including your pets. • Continuing Education: Fetch provides ten thousand per year in education reimbursement. • Employee Resource Groups: Take part in employee-led groups that are centered around fostering a diverse and inclusive workplace through events, dialogue and advocacy. The ERGs participate in our Inclusion Council with members of executive leadership. • Paid Time Off: On top of our flexible PTO, Fetch observes 9 paid holidays, including Juneteenth and Indigenous People’s Day, as well as our year-end week-long break. • Robust Leave Policies: 20 weeks of paid parental leave for primary caregivers, 14 weeks for secondary caregivers, and a flexible return to work schedule. • Calvin Care Cash: Employees who are welcoming new family members will also receive a one time $2,000 incentive to assist employees with covering the cost of childcare, clothing, diapers and much more! • Flexible Work Environment: Collaborate with your team in one of our stunning offices in Madison, Birmingham, or Chicago. Or you can work fully remotely from anywhere in the US. We’ll ensure you are equally equipped with the hardware and software you need to get your job done in the comfort of your home. • Equal opportunity and reasonable accommodations: Fetch provides reasonable accommodations to qualified individuals with disabilities or those with sincerely held religious beliefs, as required by law. Apply tot his job