Senior ML Specialist

WHO WE ARE:

Quartile , the world's largest retail media optimization platform, is a trusted partner for multichannel e-commerce success. Through unmatched expertise and patented AI technology, we fuel growth for 5,300+ brands and sellers worldwide and manage an annual ad spend exceeding $2 billion. The award-winning platform covers major marketplaces and ad channels for optimal reach. The result is unprecedented granularity, smarter budgeting, and bespoke solutions for retailers.

Quartile is proud to be an equal opportunity employer with employees stemming from a wide range of backgrounds and experiences. As a business, we value the enrichment that diversity brings to our organization and are committed to a culture that creates a sense of inclusion and belonging. We welcome new perspectives and affirm that all employment decisions are made without regard to race, color, ancestry, religion, national origin, age, familial or marital status, sex, sexual orientation, pregnancy, gender identity or expression, disability, genetic information, veteran status, or any other classification protected by federal, state, or local law.

About Sciene
At Sciene, the mission is to empower professional services firms with cutting-edge, customized AI solutions — enhancing automation, analytics, and optimization across industries while prioritizing security, cost efficiency, and state-of-the-art technology.
Our flagship product, the Sciene AI Companion , is an autonomous customer success platform deployed across Quartile — the world's largest retail media optimization platform, managing performance marketing for 1,000+ brands. It automates relationship-heavy enterprise workflows end to end: generating personalized email replies in the CSM's own voice (8x faster), building full presentation decks for client meetings (12x faster), and detecting and diagnosing account fluctuations before anyone has to ask (6x faster). None of this replaces human judgment — it removes the work that was getting in the way of it.
Read more about how we built it: Sciene AI Companion: Building an Autonomous Customer Success Platform on Databricks

OVERVIEW:

Sciene runs a production agentic AI platform : a config-driven engine where every product is an agent with its own identity, skills, tools, and quality gates, executing ReAct loops against real business data across multiple LLM providers. The platform is built; what it needs now is deeper machine learning judgment behind every model decision it makes.
The Senior ML Specialist is the team's authority on how these models actually work and how to measure them. You will decide which models run which tasks and prove it with statistically sound benchmarks, design the evaluation methodology the whole team relies on, build classifiers and fine-tuned models where they beat prompting, and diagnose model behavior from first principles rather than by trial and error. You will do this inside a production codebase — shipping, operating, and monitoring what you design.

WHO THIS ROLE IS FOR:
This is a machine learning role first and a software engineering role second. We are looking for someone whose core professional background is in machine learning and statistics — not a software engineer who adopted LLM APIs in the last few years. You should be able to explain from first principles how a large language model is trained and why it behaves the way it does, reason about model outputs as probabilistic objects, and tell whether a difference between two models on a benchmark is real or noise.

REQUIREMENTS:

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5+ years of applied machine learning experience , with a substantial part predating the current generative AI wave — training, evaluating, and deploying models, not only integrating LLM APIs

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Strong foundation in statistics and probability : hypothesis testing, confidence intervals, sampling and sample-size reasoning, bias/variance, calibration, and the ability to state when a measured difference is statistic