Scala Senior Software Engineer I, Machine Learning, ML Enablement

• We own the single entry point for ML at Etsy. Our design decisions affect every team that ships a model.
• We treat the platform as a product. Our users are Applied Scientists and Software Engineers, and our goal is to make going from experiment to production safe, fast, and self-service.
• We work closely with Applied Scientists, Data Enablement, model serving and LLM hosting teams, and product engineering partners across Etsy.
• We use generative AI and other productivity tools thoughtfully, with a focus on learning and intentional contribution.

• Design, build, and operate the services that route, orchestrate, and execute online ML inference requests at scale, with a focus on latency, throughput, reliability, and observability.
• Build orchestration capabilities such as multi-model request graphs, feature retrieval, fan-out and fan-in, caching, batching, fallbacks, timeouts, and graceful degradation.
• Enable safe model rollout and evaluation: shadow traffic, canaries, A/B and experiment integration, and online and offline evaluation workflows.
• Support both predictive models and generative (open-source LLM) workloads, including the orchestration patterns they need, such as streaming, long-running requests, and GPU-backed serving.
• Build self-service interfaces (APIs, SDKs, configuration, tooling) so scientists and engineers can onboard and ship models without platform expertise.
• Define and uphold SLOs and capacity plans. Lead monitoring, alerting, incident response, and postmortems for a tier-one system.
• Partner with users to gather feedback, drive adoption of paved paths, and plan migrations away from legacy integrations.
• Contribute to technical excellence through design reviews, code reviews, and mentorship.
• 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.

• 5+ years of software engineering experience building and operating distributed, low-latency production services.
• Experience with Scala or another functional programming language and comfort with functional patterns such as immutability, composition, and effect or concurrency libraries.
• A solid understanding of how ML inference works in production: model serving, feature retrieval, batching, latency and throughput trade-offs, and how predictive and transformer-based models are deployed and evaluated.
• Hands-on experience operating services on Kubernetes, including deployments, scaling, resource management, and debugging in production.
• Experience designing service APIs and request-routing or orchestration systems (e.g., gRPC, queues).
• Strong operational skills: metrics, tracing, alerting, on-call ownership, and performance profiling.
• A product mindset and strong communication skills. You enjoy working with internal users to understand their needs.

• Experience with cloud infrastructure, ideally GCP.
• Experience with model serving frameworks and LLM inference infrastructure (e.g., vLLM, Triton, KServe).
• Experience with experimentation platforms, feature stores, or online evaluation systems.
• Experience with GPU capacity management and cost optimization.
• Experience with Scala libraries and frameworks such as Cats Effect, ZIO, Akka/Pekko, or http4s.

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.

Etsy uses two geographic pay zones to reflect the labor markets where we compete for talent: one called Geo-1, covering the New York City metropolitan area, San Francisco Bay Area, and Seattle metropolitan area, and one called Geo-2, covering all other U.S. locations. Salary ranges for this role vary by zone and are listed below.

• Geo-1: 182,000.00 - 246,000.00 USD Annual
• Geo-2: 164,000.00 - 222,000.00 USD Annual

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.