Software Engineer (IoT)

Do you want to be at the heart of a high-growth, well-funded, digital health company, that is revolutionising the way that clinicians gain early insight into their patients’ conditions?

Xim’s Lifelight technology extracts clinical vital signs (pulse, blood oxygen, blood pressure, respiration rate) from simple video feeds (from standard webcams).

The solution is based on combining established state-of-the art machine vision (specifically Remote Photoplethysmography), signal processing and machine learning. It has been trialled at a number of the UK’s largest teaching hospitals, resulting in possibly the largest dataset of its type – one million heartbeats – for supporting machine learning. Currently registered as a Class I medical device, xim is currently in the process of securing CE marking for Lifelight as a Class IIb medical device.

The start of the technical pipeline that delivers accurate vital signs is the extraction of a high-quality signal from a tablet or phone camera. Precise control of the camera and on-device handling and processing of video and other sensor data to maximise the quality of the signal, that is then processed by our algorithms, is vital for the reliable production of clinical grade vital sign measurements.

Having recently secured further significant funding, xim is now looking to improve our ability to capture high quality data from the device camera and other sensors.

To help us we are looking for a Software Engineer (IoT) who can work at the device level to optimise the signal passed back to our vital sign prediction algorithms.

About the role

The success of the signal processing that calculates the vital signs in the Lifelight solution depends on the quality of the signal that it is fed.  This is referred to as the PhotoPlethysmoGraphic (PPG) signal. We constantly look to improve the quality of the signal and have worked with outsourced developers to do so. The importance of this work to xim’s activities means we want to accelerate the process by bringing it in-house.

We are therefore looking for a technical programmer who can work with the current team to jointly identify and then rapidly implement improvements to the solution that derives the signal from the camera.

The work is broader than just development and encompasses the creation of an environment to rapidly prototype and test different signal extraction approaches.

Reporting to the CTO, the role includes:

    • Fully understanding and taking ‘ownership’ of the current PPG signal extraction code
    • Working with the science team to identify, model, and test improvements to the PPG signal preparation capability of the Lifelight solution. Tests may be conducted against real or ‘synthetic’ subjects
    • Creating a library of synthetic subjects: these will consist of high-quality videos for use in PPG extraction experiments
    • In association with the CTO and science team, establishing technical environments to facilitate and gain insights from experiments testing different approaches to the extraction and handling of PPG signal
    • Implementing selected PPG signal extraction approaches into targeted platforms (iOS and Android). Where the platform is a medical device this must be conducted in accordance with our Quality Management System (which complies with ISO 13485 and IEC 62304)
    • With the CTO and science team, agreeing a protocol for demonstrating efficacy of PPG extraction process implementation – and apply the protocol to implemented code
    • Joining, and where appropriate leading, discussions with domain experts, working together to identify improvements to chosen signal handling methods
    • Documenting work in according the Xim Quality Management System
    • Working with the existing science team to develop an expert knowledge of the state of the art as it concerns the implementation of approaches to the optimum extraction and preparation of PPG signals
    • As required and with the CTO and science team creating similar approaches for the management of data from other device sensors, current and future (accelerometers, proximity sensors, and others)



  • Advanced native technical solution/app programming directly accessing device hardware
  • Evidence of a creative approach to solving complex technical problems
  • A relevant degree to BSc or MSc level (or above) in a relevant subject (e.g. Maths, Computer Science, Physics, Engineering)


  • Camera handling expertise and insight (covering the management of colour, exposure, focus, frame rate and quality)
  • Video processing expertise with insight into different video encoding approaches
  • Creation and management of development environments covering: source control, unit testing, release processes
  • Experience of working in a regulated sector – ideally with medical devices

Why join us?

  • Create solutions that are at the leading edge of computer and clinical science
  • Work alongside people from different backgrounds who are global experts in their field
  • Flexible working
  • A competitive salary
  • An opportunity to learn and grow in expertise in novel computing techniques
  • An opportunity to be a key part of a very fast growing, ‘disruptive’ company with the potential to truly revolutionise the delivery of many aspects of clinical care
  • An opportunity to be one of the earliest technical team members in a rapidly growing company that has been identified as a key clinical innovation over the coming decade by the NHS and UK Government

Xim is a firm proponent of diversity: we are committed to celebrating and respecting diversity, equity and inclusion in its workforce.


Xim is based on The University of Southampton Science Park, in Chilworth. The work will require some days each week onsite (at least initially) but could move to primarily remote / home working if appropriate.


If you would like to apply for this role, please send your CV to: