Software Engineer III - Full Stack; Backend-Focused, Core Platform Services

Position: Software Engineer III - Full Stack (Backend-Focused, Core Platform Services)

McKesson is an impact-driven, Fortune 10 company that touches virtually every aspect of healthcare. We are known for delivering insights, products, and services that make quality care more accessible and affordable. Here, we focus on the health, happiness, and well-being of you and those we serve - we care.

What you do at McKesson matters. We foster a culture where you can grow, make an impact, and are empowered to bring new ideas. Together, we thrive as we shape the future of health for patients, our communities, and our people. If you want to be part of tomorrow's health today, we want to hear from you. Role Summary

Ontada's Engineering team builds iKnowMed (iKM), the leading Oncology EMR platform used by thousands of clinicians across the US to manage cancer treatment - from regimen ordering and chemotherapy scheduling to genomic result interpretation and clinical trial matching.

We are hiring a Software Engineer III (P3) to design and build well-scoped core services, shared frameworks, and platform components that domain teams depend on to deliver clinical applications. This is a backend-first full-stack role - you will spend the majority of your time in Java and Spring Boot building services, APIs, and event-driven integrations, with frontend work focused on building integration layers, enablement UIs, and end-to-end validation using React and Type Script.

You will work within established architectural standards, collaborate closely with senior engineers and architects, and focus on making your services reusable, well-documented, and easy for other teams to adopt. Your success is measured not only by what you build, but by how effectively other teams can build on top of it.

This role is ideal for an engineer who: • Enjoys building the foundations that other teams build on • Cares deeply about API design, modularity, and developer experience • Wants to work in a high-impact healthcare domain where software directly affects patient outcomes • Is ready to own well-scoped services end-to-end (design through build through test through monitor) without needing to own the overall architecture Technical Environment

Layer - Technologies • Backend : Java, Spring Boot, JPA/Hibernate, Wild Fly (Jakarta EE) • APIs : RESTful services, OpenAPI/Swagger • Messaging : Apache Kafka (event-driven clinical workflows) • Data : Oracle (primary RDBMS), Redis (caching), Elasticsearch (search), Databricks (analytics/pipelines) • Frontend : React, Type Script, Webpack Module Federation • Observability : Dynatrace (logs, metrics, distributed tracing) • Infrastructure : Linux, Docker, CI/CD pipelines, Git • Healthcare Standards : HL7v2, FHIR, C-CDA, SNOMED CT, LOINC, Rx Norm • Quality : JUnit, Mockito, Integration Testing, Code Reviews • Documentation : Markdown, Mermaid diagrams, API specifications Key Responsibilities

Backend Services and API Development • Design and implement well-scoped backend services and shared components using Java and Spring Boot, following established architectural patterns • Build and maintain RESTful APIs with clear contracts, consistent error handling, and comprehensive documentation that domain teams can adopt with minimal friction • Implement event-driven integrations using Kafka - produce and consume events that connect clinical workflows across services (e.g., order state changes, lab result notifications, patient data sync) • Build data integrations and pipeline components that connect to Databricks for analytics, reporting, and clinical data processing • Write production-quality code against Oracle databases using JPA/Hibernate, with attention to query performance, transaction management, and data integrity

Core Platform Enablement • Contribute to common core services, shared libraries, and frameworks that are consumed by multiple clinical domain teams (ordering, scheduling, clinical documents, genomics) • Build services with reusability as a first-class requirement - consistent API patterns, well-defined event schemas, clear extension points • Collaborate with domain teams to understand their integration needs and usage patterns, and adapt platform services to enable rapid application development • Follow platform conventions for API versioning, event contracts, data handling, error taxonomy, and security standards

Full-Stack Integration (React and Type Script) • Build frontend integration layers, admin UIs, and enablement interfaces using React and Type Script to expose platform capabilities to end users and domain teams • Implement frontend changes required to validate end-to-end clinical workflows - ensuring backend services work correctly through the full stack • Work within the existing frontend architecture (Webpack Module Federation, legacy-to-modern migration patterns) without owning frontend architecture decisions

Quality and Testing • Develop unit, integration, and API-level tests to ensure correctness and prevent regressions • Participate in peer code reviews, applying established coding, security, and quality standards • Create and maintain clear technical documentation (Markdown, Mermaid…