Principal Software Engineer

Principal Software EngineerWe're building a world of health around every individual — shaping a more connected, convenient and compassionate health experience. At CVS Health®, you'll be surrounded by passionate colleagues who care deeply, innovate with purpose, hold ourselves accountable and prioritize safety and quality in everything we do. Join us and be part of something bigger – helping to simplify health care one person, one family and one community at a time.We are hiring a Principal Software Engineer — a deeply hands-on technical leader who thrives on solving complex problems, writing production code, and elevating the engineers around them. You will serve as the senior engineering voice across a portfolio of mission-critical clinical decision-support applications. These systems combine low-latency distributed architectures with advanced LLM, OCR, and ML pipelines running on Google Cloud.This is not an "architect-from-the-sidelines" role. You will actively design systems, write critical code, ship to production, support live environments, and mentor engineers across UI, backend, and ML. Success in this role is measured by the quality, performance, reliability, and clinical impact of what you deliver—not by presentations.What You'll DoOwn architecture and execution. Lead the technical direction of a real-time, multi-service clinical platform on GCP, while personally building the most critical and performance-sensitive components.Build production-grade LLM systems. Design and operate scalable LLM pipelines (e.g., Claude, Gemini, GPT-4-class) including prompt engineering, structured outputs, evaluation frameworks, retrieval/vector search, OCR-based document understanding, grounding, guardrails, and hallucination mitigation.Deliver real-time, high-performance systems. Architect distributed, event-driven, streaming services that support sub-second clinician experiences under heavy load, with strict SLOs and strong fault tolerance.Operationalize machine learning. Lead deployment and lifecycle management of models on Vertex AI, including feature pipelines, model registries, drift detection, A/B and shadow testing, and CI/CD-integrated quality controls.Design for scalability and change. Build flexible APIs, microservices, and data contracts that support rapid iteration, backed by strong testing, observability, and progressive delivery practices.Raise the engineering bar. Drive high-quality code reviews, establish standards across testing, CI/CD, security, and observability, and mentor engineers across full-stack and ML disciplines.Own outcomes end-to-end. Translate ambiguous clinical and business needs into delivered solutions, monitor real-world performance, and continuously iterate based on data.Partner across disciplines. Collaborate with Data Science, Product, Clinical SMEs, AI Governance, and Security teams to ensure solutions meet enterprise standards for compliance, privacy, and safety.Required Qualifications10+ years of software engineering experience with a strong record of delivering production systems at scale5+ years as a hands-on Staff or Principal-level engineer (actively coding, not removed from implementation)Expert proficiency in Python including performance tuning, concurrency, and system optimization5+ years building real-time distributed systems (event-driven, streaming, Pub-Sub) with clear latency and reliability requirements5+ years working in a major public cloud (GCP preferred: Vertex AI, GKE, Cloud Run, Pub/Sub, BigQuery, IAM, etc.)Deep experience with microservices architecture, API design (REST), and resilient systems (retries, backpressure, tracing)3+ years building and operating production ML systems (MLOps, monitoring, retraining, deployment pipelines)3+ years developing LLM-powered applications in production, including prompt design, RAG/vector search, evaluation frameworks, and performance optimizationExperience building modern UI components with React or AngularStrong computer science fundamentals, including distributed systems, algorithms, and concurrencyPreferred QualificationsExperience operating LLM systems in regulated environments (PII/PHI, governance, security, auditability)Familiarity with vector databases (e.g., Vertex Vector Search, Pinecone, Weaviate, pgvector) and advanced retrieval techniquesExperience designing evaluation frameworks for LLM systems (gold datasets, regression testing, LLM-as-judge)Strong background in CI/CD, SRE practices, and SLO-driven engineeringExperience with healthcare data standards (FHIR, HL7) and compliance frameworks (HIPAA, HITRUST)Strong communication skills, with the ability to explain complex systems to both technical and non-technical audiencesProven track record of mentoring engineers into senior and staff rolesEducationBachelor's degree in Computer Science or a related field (or equivalent experience)Master's or PhD in Computer Science, Machine Learning, or a related discipline is a plusPay Range: $144,200.00 - $288,400.00Our people fuel our future. Our teams reflect the customers, patients, members and communities we serve and we are committed to fostering a workplace where every colleague feels valued and that they belong.Great benefits for great people. We take pride in offering a comprehensive and competitive mix of pay and benefits that reflects our commitment to our colleagues and their families.This full-time position is eligible for a comprehensive benefits package designed to support the physical, emotional, and financial well-being of colleagues and their families. The benefits for this position include medical, dental, and vision coverage, paid time off, retirement savings options, wellness programs, and other resources, based on eligibility. Oak St. Health