Senior Software Engineer I, Machine Learning, Search Systems

Company Description Etsy is the global marketplace for unique and creative goods. We build, power, and evolve the tools and technologies that connect millions of entrepreneurs with millions of buyers around the world. As an Etsy employee, you will tackle unique, meaningful, and large-scale problems alongside passionate coworkers, all the while making a rewarding impact and Keeping Commerce Human.

We believe exceptional companies are built by exceptional teams, and we're intentional about it. That means hiring great people, setting them up for success from day one, and giving them real reasons to grow their careers here. We invest in development that goes beyond promotions, and we foster the trust and relationships that help people do their best work together.

What’s the role? We are looking for a Senior Software Engineer I, Machine Learning to join the Search Systems team at Etsy. This team owns the core retrieval and indexing infrastructure that powers fast, reliable, and seamless search experiences for millions of Etsy buyers. As we embark on a major next-gen infra upgrade, the team has been focused on consolidating our retrieval systems, simplifying our architecture, and unlocking new machine learning capabilities to improve relevance, performance, and developer experience.

This is a full time role reporting to the Engineering Manager.

What’s this team like at Etsy? The Search Systems team is part of the Search organization and provides the foundational technology that enables high-quality search at scale. Our mission is to ensure Etsy’s search stack is fast, reliable, and extensible—serving hundreds of millions of listings efficiently while supporting rapid ML experimentation and innovation.

This Team Is Responsible For

• Owning and operating next-gen retrieval infra and other search backends that power Etsy’s core retrieval layer.
• Unify our retrieval infrastructure (lexical and ANN infra) across Etsy products, simplify system architecture, and enable ML-based rankers in retrieval.
• Building and maintaining scalable, low-latency systems that meet strict SLAs and power live A/B experiments.
• Collaborating closely with applied scientists, Data Platform, ML Enablement teams, and product engineers to integrate new retrieval models and unlock advanced ranking capabilities.
• Utilizing numerous AI tools to unlock both individual and team velocity, developing agentic workflows while improving developer experience.

What does the day-to-day look like?

• Design, build, and maintain search backend systems and infrastructure.
• Partner with ML modeling teams to productionalize new retrieval and ranking models efficiently at scale.
• Ensure reliable data pipelines, index health, and performance.
• Develop features around indexing, query execution, and ranking infrastructure to improve latency, throughput, and system resilience.
• Collaborate with cross-functional partners across other Search ML and Enablement Teams.
• Contribute to a culture of technical excellence, mentorship, and continuous learning through regular code reviews, design discussions, and performance feedback.
• Of course, this is just a sample of the kinds of work this role will require! You should assume that your role will encompass other tasks, too, and that your job duties and responsibilities may change from time to time at Etsy's discretion, or otherwise applicable with local law.

Qualities that will help you thrive in this role are:

• You build and ship production ML systems, ideally in real-time search, recommendation, or ads systems.
• You have strong engineering and coding skills, with the ability to write high quality production code. Proficiency in Python, Scala, Java and/or other equivalent languages.
• You have experience with system performance optimization, caching strategies, and scaling high-throughput, low-latency services.
• You turn ideas into deeply reliable and well tested code that other people – or you, six months into the future – will find easy to comprehend and modify.
• You are a mindful, empathetic, and communicative member of your team.
• Hands-on experience with AI and agentic frameworks, including designing and building agentic workflows.
• Familiarity with modern retrieval and ranking techniques, including neural retrieval, semantic search, and transformer-based models is a plus.

Compensation & Benefits In addition to salary, you'll be eligible for an equity package, an annual performance bonus, and our competitive benefits that support you and your family. Base salary is determined by your location, skills, and experience.

Location We prioritize candidates based within commutable distance of Etsy’s Dublin Office. Depending on proximity, we ask team members to come in once or twice per week. Remote candidates outside commutable distance may be considered on a case-by-case basis, with the expectation of occasional travel to the office. Learn more details about our work modes and workplace safety policies here.

Salary Range What's Next If you're interested in joining the team at Etsy, please share your resume with us and feel free to include a cover letter if you'd like. As we hope you've seen already, Etsy is a place that values individuality and variety. We don't want you to be like everyone else -- we want you to be like you! So tell us what you're all about.

Our Promise At Etsy, we believe that a diverse, equitable, and inclusive workplace furthers relevance, resilience, and longevity. We encourage people from all backgrounds, ages, abilities, and experiences to apply. Etsy is proud to be an equal opportunity workplace and is committed to equal employment opportunity regardless of race, color, ethnicity, ancestry, national origin, religion or creed, sex, pregnancy (including childbirth and related medical conditions), gender, gender identity or expression, sexual orientation, age, citizenship or immigration status, marital or familial status, physical or mental disability, medical condition, genetic information, military or veteran status**, or any other characteristic protected by applicable federal, state, or local law**. If, due to a disability, you need an accommodation during any part of the interview or hiring process, please let your recruiter know and we will work with you to meet your needs. While Etsy supports visa sponsorship, sponsorship opportunities may be limited to certain roles and skills.