Backend Engineer for Experiments (Remote)
Constructor
Full-time|$80K/yr - $120K/yr|Remote|Remote — Spain About UsConstructor is revolutionizing the ecommerce landscape with our next-generation search and discovery platform designed to enhance crucial metrics such as revenue, conversion rates, and profitability. Our proprietary search engine, developed entirely in-house, leverages advanced technologies like transformers and generative LLMs to deliver exceptional search experiences, personalized recommendations, and intelligent shopping agents. As the largest department within our organization, our engineering team is dedicated to maintaining the superiority of our technology, consistently outperforming competitors in A/B testing. Our platform is engineered for extreme scalability, handling over 1 billion queries daily across 150 languages and about 100 countries, serving major ecommerce players like Sephora, Under Armour, and Petco. We pride ourselves on our problem-solving capabilities and commitment to improving the experiences of both our customers and colleagues, fostering a culture centered on empathy, openness, curiosity, and continuous improvement. Founded in 2019 by Eli Finkelshteyn and Dan McCormick, Constructor is a U.S.-based company leading the charge in AI innovation.About the TeamThe Experiments team at Constructor is responsible for creating a robust experimentation platform that includes traffic allocation, exposure logging, metric computation, statistical analysis, and user interfaces for launching experiments and interpreting results. Our platform is designed for both internal use and by customers conducting experiments with live traffic, focusing on enhancing the speed, reliability, and interpretability of experiments. Unlike conventional experimentation tools, our platform must accommodate a diverse range of customer integrations, traffic patterns, and industry-specific constraints, presenting unique engineering challenges that have significant real-world implications.The RoleThis position primarily focuses on backend development (Python services and data-intensive systems). While you will occasionally engage with the Dash UI and contribute to Spark jobs, these areas are not the central focus of the role. We prioritize correctness, observability, and product usability over complex infrastructure.Technologies: Python, FastAPI, PostgreSQL, Plotly Dash, PySpark/Databricks, AWS, CloudWatch, Sentry. (Note: Spark-related work constitutes approximately 5–10% of the role — we do not expect you to be a data engineer or manage the data platform.)What You’ll DoDevelop and maintain backend services for experiment assignment, logging, and report generation.Enhance the scalability, performance, and reliability of experiment reporting pipelines.Implement product-facing features in the UI to assist users in launching experiments and analyzing results.
Dec 3, 2025