Senior Machine Learning Engineer: Search Quality

UK (Remote)

$80K/yr – $120K/yrFull time

Posted 2 months ago

Top 1% of applicants do these two things.

The other 99% submit and hope. You're about to do something different.

Job Description

About the Job

Your primary focus will be relevance evaluation and quality improvements:

  • LLM-based evaluation. We fine-tune our own models to assess relevance. This involves teaching the model to understand query intent, represent items from messy catalog data, and align model judgments with real user behavior.

  • Real-time quality in production. Reranking, filtering, signal computation. Latency is a strict requirement, so quality vs speed tradeoff is constant.

  • Automated quality monitoring and agentic insights. Pipelines to detect degradations and find underperforming patterns. Agent-based systems that generate actionable recommendations for the product data and search configurations.

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.

  • No universal ground truth. A grocery retailer and a fashion retailer may have different perceptions on what "relevant" means.

  • Efficiency at scale. Optimizing and scaling LLM inference across our entire customer base.

Requirements

  • 4+ years shipping production ML systems

  • Experience with search, information retrieval, or recommendation systems

  • Hands-on experience with fine-tuning, evaluation frameworks, and scaling LLM deployments

  • Strong Python and PyTorch. Fluency in SQL and data orchestration tools (Spark, Airflow)

  • Experience designing and running A/B tests to validate model impact

  • Excellent English communication skills

  • Experience collaborating in cross-functional teams (ranking, product, data engineering)

Benefits

  • 🧠 Work with smart and empathetic people who will help you grow and make a meaningful impact.

  • 🎉 Regular team offsite events to connect and collaborate.

  • 🌎 Fully remote team - choose where you live.

  • 🏝️ Unlimited vacation time - we strongly encourage all of our employees take at least 3 weeks per year.

  • 🛋️ 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.

  • 💵 Base salary: $80k–$120K USD, depending on knowledge, skills, experience, and interview results

  • 📈 Stock options - offered in addition to the base salary

Diversity, Equity, and Inclusion at Constructor

At Constructor.io we are committed to cultivating a work environment that is diverse, equitable, and inclusive. As an equal opportunity employer, we welcome individuals of all backgrounds and provide equal opportunities to all applicants regardless of their education, diversity of opinion, race, color, religion, gender, gender expression, sexual orientation, national origin, genetics, disability, age, veteran status or affiliation in any other protected group.

Studies have shown that women and people of color may be less likely to apply for jobs unless they meet every one of the qualifications listed. Our primary interest is in finding the best candidate for the job. We encourage you to apply even if you don’t meet all of our listed qualifications.

Constructor logo

Constructor

Constructor is the only search and product discovery platform designed exclusively for commerce where conversions matter. Our platform delivers unmatched KPI optimization and fast ROI for enterprise ecommerce brands, retailers, distributors, marketplaces, and more — while giving customers a personalized, enjoyable shopping experience. Unlike other platforms, Constructor is the only search and product discovery solution that was built from the ground up with clickstream data and advanced AI, not merely bolted onto a legacy keyword engine. Consistently outperforming competitors by an average of 3% in A/B tests, Constructor’s cloud-based solutions harness the power of natural language processing, machine learning, collaborative personalization, and Generative AI to deliver compelling user experiences across all aspects of product discovery. From search to browsing, recommendations, collections, merchant intelligence, quizzes, attribute enrichment, and AI shopping assistants, Constructor covers the entire discovery journey.Optimizing specifically for ecommerce metrics like revenue, conversion rate and profit, Constructor generates consistent $10M+ revenue lifts for our customers, which include some of the world’s most recognized brands, like Sephora, Petco, Bonobos, Target Australia, Birkenstock, The Very Group, and many more.Constructor was named a Strong Performer in The Forrester WaveTM for Commerce Search And Product Discovery, Q3 2023, and a Visionary in the First-Ever Gartner Magic Quadrant for Search and Product Discovery. Constructor also recently received multiple G2 Summer 2025 badges—including 'Grid Leader' for E-Merchandising, E-Commerce Personalization, 'High Performer for Enterprise,' and 'Best Support.’Learn more at constructor.com.

Founded in 2015
San Francisco, California, USA
1.1K employees (43 in marketing)