Principal Software Engineer jobs in Cardiff

About The Role Deadline for applications: 11:59pm on 31st October 2025 Were looking for a Principal Software Engineer to shape the technical direction of high-profile projects and lead the delivery of modern, scalable software. Please read the following job description thoroughly to ensure you are the right fit for this role before applying. We use technology to create impactful, human-centred...

Principal Software Engineer Fully Remote | Permanent | Competitive Salary + Benefits Harrington Starr has partnered with a leading Global Payments Technology company who are seeking to hire a Principal Software Engineer to join their senior engineering leadership team. This is a rare opportunity to combine hands-on development with strategic influence, guiding architecture decisions and shaping...

Join OCI’s Edge Security team as a Principal Engineer to architect and deliver cloud-scale DDoS protection. You’ll lead design for high-performance detection and mitigation systems, drive automation and operational excellence, and set the technical direction for customer-facing DDoS capabilities across OCI’s global edge. This role requires deep expertise in Linux networking data path and...

You will report directly to the Senior Civil Engineer and your role xujxxms will be to provide superior quality Engineering Design services to allow t...

Job Title – Principal / Associate Structural Engineer Salary – £50,000 to £60,000 dependant on experience Location – Cardiff Due to strategic expansion our client has an immediate vacancy in their Cardiff office for an experienced Principal or Associate Structural Engineer with an ambition to oversee the technical delivery of a portfolio of projects allocated to them. In doing so the...

You will be a vital part of this evolution, contributing your expertise to our strategy and helping us redefine what services we offer our clients.

You will ensure buildings are designed to minimise fire risks, through contributing to the development of fire strategy reports, calculations and fire risk assessments.

My client is looking for a Principal Semiconductor Packaging Engineer to lead the development of next-generation 2.5D and 3D packaging technologies. What you’ll do: - Architect innovative 2.5D/3D packaging solutions from concept to prototype. - Lead advanced packaging R&D programmes and technology roadmaps. - Oversee design, assembly, test, and validation of complex semiconductor packages. -...

Key Responsibilities - Design, implement, and maintain software for nuclear systems, ensuring compliance with safety and regulatory standards. - Develop software for reactor control, monitoring systems, data acquisition, simulation, and predictive analytics. - Collaborate with multidisciplinary teams including nuclear engineers, electrical engineers, and safety specialists. - Apply best...

About the Job This position is for a Senior Software Engineer with a minimum of 5 years of experience in backend development and a passion for building robust, scalable systems. We are looking for an engineer with a strong background in the C# .NET ecosystem, and a preference for candidates with significant experience on AWS. Are you ready for a challenge? We’re looking for a dynamic software...

Senior/Lead Software Engineer – Fully Remote (UK) A global B2B SaaS technology business is building out its European engineering hub and is hiring multiple Senior / Lead Software Engineers (JavaScript) to develop and enhance a mission-critical platform used internationally. These are hands-on individual contributor role with strong ownership — ideal for engineers who enjoy building high-quality...

You will design and deploy robust frontend client, backend services, infrastructure automation, and cloud-native solutions by utilising your software development knowledge and your DevOps proficiency across AWS and GCP.

You will collaborate closely with cross-f...

You will be working with a high-calibre team of young, talented professionals who share a like-minded mindset, delivering top-tier implementation and technical services to clients.

You will join a cross-functional product engineering team working on the evolution and modernisation of a core SaaS platform. The focus is on building scalable, cloud-native services while improving reliability, performance, and long-term maintainability.

Software Engineer – £65,000–£85,000 + Equity – Remote (UK) - London office if preferred The Opportunity 💻 Join a fast-growing, AI-native software company building workflow automation tools used daily by thousands of professionals across people-heavy industries. The platform removes manual, repetitive work through AI, automation and thoughtful product design, helping teams move faster and focus...

You will design and build APIs that enable products, partners and AI services to work together, including: Building RESTful APIs using C# .

You will likely bring: Strong experience building backend services in C# .

You will be working closely with the Machine Learning team; however, you are not required or expected to have background in Machine Learning. This is an applied role, and we are looking to hire a software engineer with experience in cloud computing and distributed systems. In this role, you will:

Playrix — одна из самых успешных компаний по разработке мобильных игр в мире. По доходам среди всех мобильных приложений мы входим в топ-3 в мире, а в Европе мы первые. Наши игры установили 2,3 миллиарда раз (треть населения Земли), каждый день в них играет более 30 миллионов людей по всему миру! У нас большие планы на развитие и рост наших проектов, именно поэтому мы ищем сильнейших экспертов в...

You will support in reverse engineering and deep understanding of vulnerabilities, including impact analysis and automation.

You must relish the challenge of findings critical vulnerabilities in complex software binaries through automation and manual practices. Creativity is highly valued; being able to find novel vulnerabilities is essential in this role.

Software Engineer Fully Remote | Permanent | Competitive Salary + Benefits Harrington Starr has partnered with a leading Global Payments Technology company who are seeking to hire a Software Engineer to join their growing engineering team. This is an exciting opportunity to work on scalable, resilient systems while contributing to real-world solutions in the financial technology space. Key...