Principal Software Engineer jobs in County of Cardiff

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...

You should also expect to work across the full stack and every stage of the product lifecycle, from system design through to build, test, deployment and supporting systems in production, so you should be skilled in practices like TDD, CI/CD, IaC and Observability.

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...

Opportunity to join a growing SME as they continue to develop their excellent C&S consulting engineering practice in the UK: - Opportunity to join as a senior/ principal civil engineer, as part of a thriving team and close to the owner director engineers - Relatively young practice (more than 10 years old), with a high-quality blend of people who have joined from larger practices and SMEs -...

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. -...

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...

Job Description About SystemsX At SystemsX, we’re a fast-growing technology company specialising in AI-driven solutions for customer-centric businesses such as call centres and service organisations. Our mission is to use innovative technology to improve operations, customer experience, and business growth. As we expand rapidly, we offer our team the opportunity to grow with us, take real...

Job Description Principal / Associate Smart Building Technical Engineer - Building Technology Systems Join to apply for the Principal / Associate Smart Building Technical Engineer - Building Technology Systems role at WSP in the UK & Ireland. What we will be looking for you to demonstrate - A passion for the future of technology in the built environment, and deep curiosity for exploring its...

I'm partnered with an early-stage, post-revenue AI startup is building an end-to-end operating system to help businesses detect and resolve complex B2B issues before they become costly or disruptive. The product is already being used by large enterprises across multiple industries, and demand is growing fast - hence this hire! Backed by a top-tier European venture fund, the company is tackling a...

You should be comfortable with most of our core technologies:

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...

SOFTWARE ENGINEER REMOTE (OPTION TO RELLOCATE) £110K + EQUITY THE COMPANY This innovative AI startup is redefining safety and reliability in AI models. While competitors like GPT and DeepMind struggle with hallucinations and illegal content generation, this company adds safety control layers to ensure AI outputs are trustworthy and compliant. Working with high-profile, they’re building AI...

At Orange Logic, we’ve been solving complex content challenges for over two decades—driven by innovation, curiosity, and a passion for impact, our intelligent Digital Asset Management (DAM) system, Orange Logic Platform, empowers organizations across industries to manage, access, and leverage their digital assets more effectively. We’re not just building powerful software—we’re building a team of...

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 shape both how interactions are built and what expressive capabilities are possible, translating cutting-edge research into robust, real-world systems.

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.

At SystemsX, we’re a fast-growing technology company specialising in AI-driven solutions for customer-centric businesses such as call centres and service organisations. Our mission is to use innovative technology to improve operations, customer experience, and business growth. As we expand rapidly, we offer our team the opportunity to grow with us, take real ownership of their work, and help...

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...

About SystemsX At SystemsX, we’re a fast-growing technology company specialising in AI-driven solutions for customer-centric businesses such as call centres and service organisations. Our mission is to use innovative technology to improve operations, customer experience, and business growth. As we expand rapidly, we offer our team the opportunity to grow with us, take real ownership of their...

The Oracle Cloud Infrastructure (OCI) Offensive Security team provides OCI with the capabilities to ensure our systems and services meet the security objectives we communicate to customers. The Offensive Security group performs security assessments, vulnerability research, static and dynamic analysis research, penetration testing, red-teaming, and security tool development. We ensure the security...