Senior Software Engineer

Job Description:
Our Opportunity
Chewy Ads business is growing rapidly, and we're looking for experienced Senior Backend Engineers to help drive the evolution of our advertising platform powered by Machine Learning (ML). This role focuses on building scalable, high-performance backend systems that power ad auctions, targeting, ranking, bidding optimization, and performance measurement. As Chewy continues to expand ML-driven capabilities across Ads, this role will also play a critical part in enabling reliable, scalable, and observable ML systems in production. You'll help bridge backend engineering and ML Ops practices to ensure our models are production-ready, continuously deployed, and delivering measurable impact. You'll lead backend and platform development efforts, mentor junior engineers, and shape one of Chewy's fastest growing and most strategic revenue streams.
Launched in 2022, the Chewy Ads platform enables vendors to promote their products onsite and offsite, significantly contributing to Chewy's revenue growth. The platform powers auction-based ad placements, targeting and personalization systems, performance reporting, and optimization tools. The team manages both customer-facing and vendor-facing experiences while building backend systems and ML infrastructure that support bidding strategies, ranking models, relevance scoring, and budget optimization.
Based in Boston and Seattle, we operate with a startup mindset and maintain high operational rigor.
What You'll Do:

• Lead the architecture and delivery of scalable backend services supporting auction processing, targeting, ranking, and reporting.
• Design and implement low-latency Java and Python services that power realtime ad decisioning systems.
• Improve system reliability, scalability, and performance through strong observability, metrics, and SLO-driven development.
• Design and implement production infrastructure to deploy, serve, and monitor ML models used for ad ranking, targeting, and optimization.
• Partner with Data Scientists to launch ML models, including feature pipelines, model packaging, inference endpoints, and A/B testing frameworks. o Build and maintain CI/CD workflows for ML artifacts, enabling reproducible training, versioning, validation, and deployment.
• Implement model monitoring systems to track performance drift, data quality issues, latency, and business impact metrics.
• Contribute to feature store design, real-time feature pipelines (Kafka-based), and batch processing systems.
• Support safe experimentation through controlled rollouts, shadow testing, and canary deployments of ML models.
• Ensure governance, auditability, and traceability of ML systems in production.
• Mentor junior engineers and raise the bar on engineering excellence across backend and ML-integrated systems.
• Lead technical design reviews and architectural discussions, particularly for distributed and ML-powered systems. o Drive best practices around reliability, observability, automation, and DevOps/MLOps standards.
• Own project estimation, planning, and delivery in partnership with Product, Data Science, and cross-functional stakeholders.

What You'll Need:

• Bachelor's degree in Computer Science or related field (or equivalent experience).
• 8+ years of experience as a Software Engineer with strong backend expertise.
• 3+ years of experience with MLOps.
• Proven experience building scalable, highly available distributed systems.
• Hands-on experience deploying, managing, and operating ML workloads in AWS SageMaker, including model training, deployment endpoints, batch transform jobs, model versioning, and monitoring.
• Experience launching ML models and partnering closely with Data Science teams to move models from experimentation to reliable production systems.
• Strong understanding of MLOps practices including model CI/CD, artifact versioning, reproducibility, automated validation, and rollout strategies (canary, shadow, A/B).
• Experience building or supporting real-time inference services and/or asynchronous ML pipelines.
• Experience deploying and operating services in AWS cloud environments (ECS/EKS, Lambda, S3, IAM, etc.).
• Solid understanding of streaming systems (Kafka), data pipelines, and SQL/NoSQL storage systems.
• Experience with observability tooling for both services and ML systems (metrics, tracing, logging, drift detection).
• Strong debugging and performance optimization skills.
• Solid CS fundamentals: object-oriented design, algorithms, and problem-solving.
• Excellent verbal and written communication skills.

Bonus:

• Experience in Ad Tech and/or e-commerce.
• Experience building large-scale ranking, auction, or recommendation systems.

The base salary range for this role is $141,000 - $225,500.

• The specific salary offered to a candidate may be influenced by a variety of factors including but not limited to the candidate's relevant experience, education, and work location. In addition, this position is eligible for 401k and a new hire and annual equity grant. C08+ positions may also be eligible for annual bonus.

We offer different types of insurance and benefits, such as medical/Rx, vision, dental, life, disability, hospital indemnity, critical illness, and accident. We offer parental leave, family services benefits, backup dependent care, flexible spending accounts, telemedicine, pet adoption reimbursement, employee assistance program, and many discounts including 10% off pet insurance and 20% off at Chewy.com.
Exempt salary team members have unlimited PTO, subject to manager approval. Team members will receive six paid holidays per year. Team members may be eligible for paid sick and family leave in compliance with applicable state and local regulations.
Chewy is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, ancestry, national origin, gender, citizenship, marital status, religion, age, disability, gender identity, results of genetic testing, veteran status, as well as any other legally-protected characteristic. If you have a disability under the Americans with Disabilities Act or similar law, and you need an accommodation during the application process or to perform these job requirements, or if you need a religious accommodation, please contact [email protected].
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