Mckesson Coding Jobs in California (NOW HIRING)

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 TypeScript.

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

Layer - Technologies

• Backend: Java, Spring Boot, JPA/Hibernate, WildFly (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, TypeScript, 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, RxNorm

• Quality: JUnit, Mockito, Integration Testing, Code Reviews

• Documentation: Markdown, Mermaid diagrams, API specifications

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 TypeScript)

• Build frontend integration layers, admin UIs, and enablement interfaces using React and TypeScript 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 diagrams, API specs) that enables domain teams to self-serve

Observability and Production Support

• Use Dynatrace for log analysis, metrics review, and distributed trace investigation to diagnose and resolve production issues with guidance from senior engineers

• Implement structured logging, telemetry, and error-handling patterns defined by the platform team

• Identify and implement incremental improvements to service reliability, performance, and operational visibility within your owned components

Agile Execution

• Participate actively in sprint planning, backlog refinement, sprint reviews, and retrospectives

• Deliver committed work predictably, surface risks early, and communicate blockers clearly

• Adopt approved tools, frameworks, and CI/CD patterns defined by platform and architecture teams

We are unable to offer or provide sponsorship for this role presently or in the future.

Degree or equivalent and typically requires 4+ years of relevant experience.

Bachelor's degree in Computer Science, Software Engineering, or equivalent practical experience.

Critical Skills

Backend (Primary - 70% of the role)

• 5 to 7 years of professional software development experience, with the majority in backend/server-side development

• Strong proficiency in Core Java and Spring Boot (dependency injection, REST controllers, data access, testing)

• Experience designing and implementing RESTful APIs consumed by multiple client applications

• Practical experience with event-driven architectures - producing and consuming messages via Kafka or equivalent

• Solid understanding of relational databases - SQL, ORM (JPA/Hibernate), indexing, query optimization, transaction management

• Experience working with or integrating into data platforms (Databricks, Spark, or equivalent) for analytics or pipeline support

• Ability to investigate production issues using Dynatrace - navigating logs, analyzing response time metrics, and following distributed traces

Full-Stack and Frontend (Secondary - 30% of the role)

• Working experience with React.js and TypeScript

• Understanding of how frontend applications consume backend APIs, handle state, and render data

• Ability to build or modify frontend components to support end-to-end feature delivery

Foundational

• Solid understanding of Linux/Unix environments, shell scripting, and basic networking

• Experience with Git, CI/CD pipelines, and automated testing practices

• Clear written and verbal communication - ability to document services and explain technical decisions

• Experience in healthcare IT or familiarity with clinical data standards (HL7, FHIR, C-CDA, SNOMED, LOINC, RxNorm)
• Experience building shared libraries, SDKs, or platform services consumed by other engineering teams
• Exposure to containerization (Docker) and orchestration
• Experience with Elasticsearch for search or indexing use cases
• Familiarity with Agile/Scrum methodologies in enterprise environments

This position offers the possibility of a hybrid work arrangement based on recent updates to our in-office/workfromhome model. If located in DFW area, the selected candidate may be expected to work onsite at our Las Colinas office a minimum of two (2) days per week, with the remaining days worked remotely. Specific inoffice days may be designated according to team needs and business priorities.