Staff Machine Learning Engineer, AdTech

The Growth Tech Alliance's goal is to enable HelloFresh to drive smarter marketing through AI-powered automation, intelligent systems, and advanced optimization. We've pioneered cutting-edge approaches to programmatic campaign optimization using state-of-the-art AI/ML technologies and are now scaling these capabilities across our global marketing operations. Our team’s key responsibilities include designing, building, maintaining autonomous decision-making systems, advanced ML models for marketing optimization, and real-time intelligence that drives measurable business impact. We work at the intersection of modern AI architectures, agentic systems, and enterprise-scale ML operations.

We are looking for a Staff Machine Learning & AI Engineer to lead the engineering architecture of our multi-agent AI systems, with a focus on agent-driven products. In this role, you will bridge the gap between our data scientists and backend engineers, connecting internal automation APIs, AI agents, and the supporting ML models into a cohesive production platform.

At HelloFresh, Staff Engineers are hands-on builders. You will spend roughly 50% of your time writing production code and building critical systems, and 50% driving technical direction through architecture reviews, RFCs, and mentoring engineers and data scientists across the team.

Lettuce share what this role will be responsible for

• Design, build, and maintain production multi-agent AI systems and LLM workflows using modern orchestration frameworks such as LangChain and LangGraph.
• Build the APIs, tool-calling interfaces, and MCP integrations that connect our internal marketing automation services with AI agents and third-party platforms.
• Partner with Data Scientists to take machine learning and statistical models from prototype into reliable production, and connect them to the agents that create, launch, and optimize ads.
• Design end-to-end system architectures across our models, databases, and backend services, optimizing for reliability, correctness, and long-running workflows at scale.
• Build evaluation pipelines, guardrails, state management, and human-in-the-loop approval workflows to ensure AI and ML systems run safely in production.
• Author RFCs and Architecture Decision Records (ADRs) to align the team on technical direction and solve cross-team architectural challenges.
• Raise the engineering bar across the team through code reviews, system design guidance, and active mentorship of Senior Engineers and Data Scientists.
• All other duties, as assigned

Sound a-peeling? Here's what we're looking for

• Extensive hands-on experience in Machine Learning Engineering, AI Engineering, or Backend Software Engineering, with a strong track record of building and operating distributed production systems.
• Production proficiency in Python and SQL, with strong fundamentals in software design, API development (e.g., FastAPI), testing, and database optimization.
• Hands-on experience building and deploying production LLM and agentic applications beyond simple prototypes, including agent orchestration (LangGraph/LangChain or similar), tool use, MCP, context management, and automated evaluations.
• Experience with A/B testing or other experimentation methods (e.g., synthetic testing) to validate changes before and after launch.
• Experience with multi-agent systems (e.g., supervisor and sub-agent designs) and the ability to explain the trade-offs between single-agent and multi-agent approaches.
• Experience with multimodal AI models (vision-language models for image or video analysis and generation).
• Experience building systems where predictive ML models and LLM-based agents work together to drive automated decisions.
• Prior background in AdTech, MarTech, e-commerce growth, or high-scale consumer platforms.
• Familiarity with deploying and scaling classical machine learning or deep learning models in production, alongside solid MLOps practices (CI/CD, model monitoring, and automated pipelines).
• Experience working with modern cloud and data platforms such as Databricks, Unity Catalog, MLflow, Docker, and AWS.
• Proven experience operating at a Staff or Principal level—able to think in systems, navigate ambiguity, write clear technical specs, and mentor other engineers.

Let’s cut to the cheese, this is why you'll love it here

• Box Discount - Amazing discounts on 1 box per week! 75% discount on weekly HelloFresh and Chefs Plate meal kits AND 50% off weekly Factor meal box.
• Health & Wellness - Health & Dental benefits from day 1, a Health Spending Account, unlimited access to the Headspace app to meet your self-care needs, and 25% discount on GoodLife fitness memberships!
• RRSP Matching - Competitive RRSP matching program offered
• Vacation & PTO - Time off is also an important part of self-care! We offer generous vacation and PTO to help you create a good work-life balance.
• Family Benefits - A parental leave top-up program for