backend engineer jobs in Cardiff

Job Description 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...

You will work closely with frontend engineers, product managers, and the CTO to design and evolve a highly scalable, asynchronous, cloud-native platform. This is a hands-on senior engineering role with real technical ownership, influence over architecture, and scope to mentor others.

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 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:

Job Description 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...

Job Summary Take the next step in your career now, scroll down to read the full role description and make your application. Aviation. It connects our world, brings people together, provides opportunities, accelerates economic growth, and is just so very cool! Come work for NAVBLUE, a leading services company owned by Airbus, dedicated to Flight Operations, Air Traffic Management solutions and...

You should apply if: - you have strong experience working on the backend of a technology product - you want to be involved in building a product that you (and the people you know) use every day - you have a product mindset: you care about customer outcomes and you want to make data-informed decisions

You will write beautiful and smart code, run tests and coach a team of developers on the client and partner side.

You will also provide training to those who work with the platform. You know when to be creative and when to consult your colleagues.

You will encounter situations that demand prompt, yet smart actions.

Job Description Senior Full Stack Engineer Remote (UK) | Full time London office available for optional in person collaboration We’re looking for an experienced Senior Full Stack Engineer to join a small, highly skilled team building a next generation Financial Services Regulatory Compliance platform. This is a hands on role where you’ll work across the stack, leading frontend development...

Job Description Senior ML & AI Engineer Remote (Bath office 1 day per month) Up to £80,000 About the Role We’re partnered with a fast-growing tech startup focused on how brands and retailers use data. Their AI platform brings together data science, immersive visualisation, and large-scale machine learning to optimise product ranges, plan shopper journeys, and drive smarter commercial...

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 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.

Job Description Engineering Manager – Mobile (Android & iOS) 📍 Leeds, UK | Hybrid Working We’re looking for an experienced Engineering Manager (Mobile) to lead the development and operation of high-traffic Android and iOS applications used daily by millions of users across multiple European markets. This is a hands-on leadership role where you’ll guide a cross-functional squad, drive...

📍 Remote | Full-Time 👋 About Us Medify is a mission-driven EdTech company widening access to medicine and healthcare careers. Our platform supports thousands of learners preparing for high-stakes admissions exams, and our engineering team plays a critical role in delivering reliable, scalable, and high-quality learning experiences. Medify Engineering is a team of ten engineers across two...

Job Description 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...

Job Description 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,...

You should apply if: - you have strong experience working on the backend of a technology product - you want to be involved in building a product that you (and the people you know) use every day - you have a product mindset: you care about customer outcomes and you want to make data-informed decisions

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.

You should apply if: - you have strong experience working on the backend of a technology product - you want to be involved in building a product that you (and the people you know) use every day - you have a product mindset: you care about customer outcomes and you want to make data-informed decisions