Senior Software Engineer – Platform

What you'll actually own

You build the software backbone that every Zooly product runs on. Sensors and algorithms only matter if a surgeon can trust what shows up on the screen in real time, and that path, from device connectivity and data acquisition through calibration, visualization, and decision support, is yours to design and build across our hip, knee, and shoulder products. The best software here is creative and simple at once: reusable where it should be, dead-reliable where it has to be. If our products feel fast, clear, and trustworthy in the operating room, it will be because you built the foundation right.

Where the business is 12 months after you join

If this hire goes the way we intend, one year from now:

• There is one shared software platform that every product team builds on, instead of three one-off codebases.
• Device connectivity and data pipelines are reliable enough to run in cadaver labs and clinical studies without drama.
• Software ships on a real cadence with automated tests, code review, and the traceability a regulated device needs, and none of it slows the team down.
• Surgeon-facing features go from idea to working prototype in days, not months.

About Zooly

Zooly Labs is on a mission to make advanced surgical guidance more accessible for joint replacement surgery. Joint replacement can restore mobility and quality of life, yet surgeons often have limited objective information during the procedure to assess joint behavior and guide decisions. We build AI-guided technology that combines intelligent sensing, real-time data, and decision support with familiar surgical workflows and standard instruments, without large capital equipment. We are an early-stage company building a scalable platform across hip, knee, and shoulder.

How we work at Zooly

Patient-driven. Design-obsessed. We're an in-person team of curious, driven people who care about getting the details right, because there's a patient on the table counting on us. A few beliefs shape how we build, and this role lives at the center of them.

• Master your craft. We invest in people who go deep. There is no ceiling that forces a great engineer or designer into management to advance. Go as far into your craft as you want.
• Act like an owner. We take responsibility for our decisions and how we communicate, we think long-term, and we bias toward action.
• Build it together. We want people who want to be in the room, solving hard problems face to face. The camaraderie is not a perk, it is how we do our best work.

What this role is really like

This is a hands-on role at a fast-growing startup racing real deadlines. You will architect a reusable module one day and debug why a sensor stream drops packets the next. You will set the engineering practices the rest of the team builds on, and you will still write plenty of code yourself. If you want a narrow lane and someone else's architecture to maintain, this is not the role. If you want to define how an entire product platform is built, it is.

What you'll do

• Design and build the platform software for device connectivity, streaming data, calibration, workflow, visualization, storage, playback, and reporting.
• Build reusable APIs and modules that serve the hip, knee, and shoulder products and multiple sensing modalities.
• Build the surgeon-facing dashboard features, working directly with the product engineers and UI/UX.
• Set the coding standards, architecture, CI/CD, automated testing, defect tracking, and release process the whole team lives by.
• Produce the software requirements, architecture, design, test evidence, traceability, and release records a regulated device needs.
• Debug across the boundaries: software, embedded devices, networks, sensors, and user interfaces.
• Work closely with the electrical, systems, data science, cybersecurity, quality, and regulatory engineers to move software from prototype to release.

What you need to be able to do

These are capabilities, not credentials. If you can do these things, we want to talk regardless of how many years it took you to get here.

• You have personally owned production-quality software or a platform end to end, ideally in medical-device or another regulated, safety-critical setting.
• You are strong in modern software architecture and at least one relevant stack (C/C++, C#, Python, Swift/Kotlin, Dart/Flutter, JavaScript/TypeScript, or similar).
• You have built reliable device connectivity, streaming-data acquisition, synchronization, APIs, data persistence, diagnostics, logging, and real-time or near-real-time visualization.
• You design modular, testable, maintainable software and can stand up code review, automated testing, CI/CD, version control, release management, and defect tracking from scratch.
• You can turn product and system requirements into software requirements, architecture, design, tests, and traceable verification evidence.
• You debug hard problems across software, embedded devices, networks, sensors, and UIs.
• You can define a shared architecture that multiple product teams build on, and bring people with you.
• A degree in computer science, software engineering, or a related field is common in people who do this well, but the ability above matters more than the diploma.

What would make you a strong fit

• Experience building software for medical devices, surgical navigation or robotics, connected hardware, digital health, or other safety-critical products.
• Working knowledge of IEC 62304, medical-device cybersecurity, software risk management, and FDA software documentation.
• Experience with BLE, Wi-Fi, serial protocols, embedded devices, sensor data, real-time graphics, or edge computing.
• Experience building clinician-facing workflows with human-factors and UI/UX partners.
• Experience with cloud-connected architectures, analytics pipelines, secure data management, or putting ML/AI into production software.

How this role works with the rest of the team

You are the software anchor for the whole company. You work directly with the engineers building each joint product and the engineers who design the sensors and electronics, turning what they need into shared software everyone can build on. You will also mentor the other software engineers, including the team in India. The point of a shared platform is that no one reinvents the basics, so you can all go deep on the hard, product-specific problems.

Stay curious

We hire curious people. The kind who took things apart as kids and never stopped asking how things work. If that sounds like you, we'd love to meet.

The fine print

Zooly Labs is an equal opportunity employer and evaluates candidates without regard to legally protected characteristics. Responsibilities will evolve as the company and product portfolio grow. This is an in-office role in Boulder, CO. The role may require occasional travel to design labs, surgeon meetings, suppliers, cadaver studies, or clinical sites. Compensation, equity, benefits, and work-authorization details will be discussed directly.