Our client, a leader in the defence and security sector, is seeking a Principal Software Engineer to join their team in Berkshire. This is a permanent role where you will provide technical leadership within their Cyber Unit.Key Responsibilities:Architect, specify requirements, design, implement, and test embedded and/or application software to ensure high quality and timely deliverables.Apply object-oriented design techniques for code re-use and integration with testing frameworks.Review system design artefacts to derive software requirements and architecture.Use modelling tools to design, document, review, and maintain the software design.Develop knowledge of best practice development processes and standards.Estimate time and effort for software activities and deliver according to these estimates.Contribute to the Software Community of Practice to support quality and innovation.Generate and review technical proposals, and mentor less experienced engineers.Job Requirements:Willing and able to obtain and maintain SC and DV security clearance.Qualifications / Skills Required:Degree in engineering, mathematics or science-based subject, or equivalent experience.Significant experience in one of the following:Embedded product development (including bare-metal and RTOSes such as ThreadX, QNX or Linux)Embedded Linux application, kernel and/or driver developmentC and C++Significant experience of best practice software development processes/lifecycles.Experience of Object-Oriented Desi