backend software engineer jobs in Cardiff

About the Team Dex is an AI-powered recruiter, matching exceptional software engineers with top tech companies. We're one of the fastest-growing UK startups, and have raised $3.1M from a16z and Concept Ventures to build a best-in-class voice agent, matching engine and web app experience that will redefine the way that talent and opportunity connect. We're hiring a Python engineer to join our...

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:

About Prighter Prighter is a fast-growing LegalTech company building productised services and SaaS solutions for compliance with data protection as well as AI & digital governance regulations. With the mission to enable companies around the world to comply with regulatory requirements for their digital business, our services and SaaS solutions guide our global clients through the increasingly...

You will be responsible for the entirety of the back end features of the products.

You will be in charge of building scalable backend services and awesome messaging queues.

You will be responsible for developing a Python-based back end platform that's handling 100,000+s of interactions daily.

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...

Lead Software Engineer Stealth AI Fintech Startup | London | Hybrid (3 days on-site) We’re hiring on behalf of an innovative Fintech startup that is building an AI-driven platform that’s rethinking how investors analyse, access, and manage alternative assets (e.g. private equity, private credit and other private markets). They've built there MVP, raised funding from experienced fintech...

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 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.

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...

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...

Software Development Engineer III Expedia Group brands power global travel for everyone, everywhere. We design cutting-edge tech to make travel smoother and more memorable, and we create groundbreaking solutions for our partners. Our diverse, vibrant, and welcoming community is essential in driving our success. Why Join Us? To shape the future of travel, people must come first. Guided by our...

You will be joining a fast growing technology company building a production grade platform that enables advanced AI driven products.

You will have real ownership, influence over technical decisions and the space to build things the right way.

You will be trusted to take responsibility across the stack, including

Software Engineer Tech Stack: C# / .NET / Git / Azure Location: Fully Remote (no office travel required) Salary: £55,000 – £65,000 + Benefits This is an excellent opportunity to join a small but growing insurance software company, as they look to expand their development team. You’ll work across a variety of initiatives, including their core product development, system migrations, and...

You will work as part of a collaborative R&D team focused on delivering high-quality features, and developing the client architecture using the latest UI patterns.

You will work closely with developers on Next.

You will work across the stack, building robust back-end systems in TypeScript, Node. js, and PHP, and delivering high-quality front-end experiences using modern JavaScript frameworks. The role requires expertise in database design, DevOps, cryptographic data handling, and AWS cloud technologies.

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# .

About The Role Deadline for applications: 11:59pm on 31st October 2025 Applying for this role is straight forward Scroll down and click on Apply to be considered for this position. Were looking for a Principal Software Engineer to shape the technical direction of high-profile projects and lead the delivery of modern, scalable software. xujxxms We use technology to create impactful,...

You will be responsible for the entirety of the back end features of the products.

You will be in charge of building scalable backend services and awesome messaging queues.

You will be responsible for developing a Python-based back end platform that's handling 100,000+s of interactions daily.

You will work as part of a collaborative R&D team focused on delivering high-quality features, and developing the services architecture. This role is ideal for an engineer who thrives in complex systems and is looking to develop new services that exploit a cloud-native ecosystem while modernizing legacy services into a containerized, cloud-native ecosystem.