Principal Software Engineer

MML US Inc•San Diego, CA

58d•$190,000 - $210,000

About The Position

Mainstay Medical is a medical device company focused on marketing an innovative implantable neurostimulation system, ReActiv8®, for people with disabling chronic mechanical Low Back Pain. The company is headquartered in Dublin, Ireland, with subsidiaries operating in the United States, Australia, the United Kingdom, and Germany. The Principal Software Engineer leads the architecture and technical direction for the next-generation ReActiv8 Class III active implantable medical device. The individual serves as the technical lead of the software engineering team, establishing architecture frameworks, driving design decisions, and owning platform strategy — all within the regulatory and quality requirements of a PMA-class implantable device. Strong systems thinking, hands-on software architecture experience in safety-critical environments, and the ability to align clinical, regulatory, and business requirements into scalable, maintainable solutions are essential.

Requirements

Bachelor's degree in Computer Science, Computer Engineering, or equivalent.
15+ years of software engineering in product development; 8+ years in regulated medical device environments.
Demonstrated experience with IEC 62304 software development lifecycle, with Class III implantable or other safety-critical device experience strongly preferred.
Direct experience supporting FDA PMA or 510(k) submissions and design control documentation.
Proficiency in .NET, C#, Blazor, and .NET MAUI — the core technology stack for the ReActiv8 clinician programmer and patient mobile application.
Experience with EF Core and SQLite for data persistence.
Hands-on experience with Azure services for connected medical device ecosystems.
Proficiency with Azure DevOps and Git for CI/CD pipeline management and source control in a regulated environment.
Experience in embedded firmware development and cross-domain system integration (firmware ↔ mobile ↔ cloud).
Familiarity with Figma for UX design collaboration and design review in a cross-functional team.
Experience with Bluetooth and wireless connectivity protocols relevant to implantable device communication.
Familiarity with gRPC for service communication within cloud or device-connected architectures.
Experience leading software teams in an Agile/SCRUM framework as a technical lead or principal-level engineer.
Strong cybersecurity background aligned with FDA guidance for connected implantable devices.
Excellent communication and stakeholder management skills; able to translate complex technical concepts for clinical, regulatory, and executive audiences.

Responsibilities

Lead the architecture and technical evolution of the ReActiv8 system across embedded firmware, mobile, web application, and cloud infrastructure.
Define and maintain software architecture strategies including component decomposition, interface contracts, data flow, and integration patterns across the full system stack.
Translate clinical user needs, regulatory requirements, and business objectives into scalable, maintainable software designs compliant with IEC 62304 and FDA PMA expectations.
Establish and enforce architecture frameworks, design principles, coding standards, and technical conventions for the software team.
Lead architecture reviews, technical risk assessments, and design control activities including requirements traceability, hazard analysis contributions, and verification strategy.
Drive Agile/SCRUM ceremonies and technical decision-making as the engineering team's technical leader; collaborate with Product, Quality, and Regulatory.
Maintain and evolve tools and development practices: Azure DevOps, Git, Figma, and Claude Code for AI-assisted development workflows in a regulated software context.
Mentor and provide hands-on technical guidance to software engineers across firmware, application, and cloud domains.
Support FDA regulatory submissions and design documentation; participate in internal/external audits and regulatory inspections.
Ensure cybersecurity principles are incorporated throughout the system architecture in line with FDA guidance for connected and implantable devices.