Senior Machine Learning Engineer: ML Recall

About Us

Launched in 2019, Constructor is an AI-first ecommerce search and discovery platform that helps shoppers find the right products at the right time and enables leading global e-commerce brands to drive meaningful revenue and conversion gains.

As a member of the ML Recall team, you will improve the e-commerce experience for hundreds of millions of users across the world by building the retrieval layer of our search engine.

The mission is to make sure the product a shopper looks for is always among the results - for any query, in any language, in a few milliseconds.

About the Job

Your primary focus will be search retrieval and visual solutions:

• Search Recall. A modern retrieval stack with dense and sparse models, plus query understanding. Latency is a strict requirement, so quality vs speed tradeoff is constant.
• Visual and multimodal search. End-to-end visual solutions: image search, shop the look, visual recommendations.
• Models as a platform. Our team owns a wide range of deep learning models, and other teams build on top of them.

What makes this interesting

• Multi-domain, multi-language, at scale - 40+ languages, 20+ domains. The models need to generalize across all of them - without per-customer rules or overrides.
• Real room for R&D. You will experiment with new architectures and approaches, A/B test them on live traffic, and deliver measurable business value.
• The measurement challenge. You can't measure what was not returned - a missed product leaves no trace in the logs, and the query looks like it worked. Building the ground truth to catch that is part of the modeling work.

Requirements

• 4+ years shipping production ML systems
• Experience with search, information retrieval, or recommendation systems
• Hands-on experience training, fine-tuning, and evaluating transformer models
• Strong Python and PyTorch. Fluency in data orchestration tools (Spark, Airflow)
• Experience owning a model end to end - from problem framing to rollout
• Experience designing and running A/B tests to validate model impact
• Excellent English communication skills

Benefits

• 🏝️ Unlimited vacation time - we strongly encourage all of our employees take at least 3 weeks per year
• 🌎 Fully remote team - choose where you live
• 🛋️ Work from home stipend! We want you to have the resources you need to set up your home office
• 💻 Apple laptops provided for new employees
• 🧑‍🎓 Training and development budget for every employee, refreshed each year
• 👪 Maternity & Paternity leave for qualified employees
• 🧠 Work with smart people who will help you grow and make a meaningful impact
• 💵 Base salary: $80k–$120k USD, depending on knowledge, skills, experience, and interview results
• 📈 Stock options - offered in addition to the base salary
• 🎉 Regular team offsites to connect and collaborate