principal .net engineer jobs in Doncaster

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.

You will define technical strategy, design scalable data systems, mentor senior engineers, and partner closely with product, engineering, analytics, and business leaders to transform strategic goals into robust, data-driven solutions.

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.

Senior Backend Developer (.NET | AI-First SaaS Platform) Compensation: Competitive, based on location and experience Location: UK or Turkey (Hybrid – Office & Remote) Keepnet is an AI-driven SaaS platform experiencing strong, sustained growth in the UK with growing global momentum, helping organisations manage human cyber risk at scale. With Agentic AI live in production, Keepnet runs...

About Intellias Intellias is a European-founded AI, Data and Software Development company with global delivery capability across Europe, India and Latin America. For more than 20 years, we've empowered our customers to embrace innovation at scale and contributed to the success of the world's leading brands. The company is featured in the Inc 5,000 Europe and IAOP Global Outsourcing...

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.

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 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:

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 a great fit if you: - Have 5+ years full-stack experience, with strong JavaScript/TypeScript depth. - Are backend-leaning, with deep Node. js and API experience. - Have previously worked in early-stage start-ups or very lean engineering teams. - Have extensive evidence of being a hands-on individual contributor in complex codebases.

We’re working with a forward-thinking digital product organisation on a mission to become truly AI-native — not just by adopting tools, but by transforming how software is designed, built, and delivered. They’re looking for a Senior AI Enablement Engineer to play a pivotal role in redefining modern engineering practice through AI-assisted development. This is a hands-on senior engineering role...

Title: Forward Deployed Engineer – AI & Customer-Facing Technical Leader Location: Remote Travel: Customer visits 4–5 days/month; occasional team gatherings Salary: Senior: €130–150k base + growth trajectory Principal: €160–200k base + package discussion Tech: Python, JavaScript, Azure, AWS, AI, LLM's, RAG Industry: AI Consultancy The Role We’re looking for talented engineers to join our...

Role: Principal Electrical Engineer Location: Devonport(Hybrid role requiring onsite presence 2 days/month) Duration: 2 years Inside IR35: Umbrella About our Client: Our client in Devonport is a leading engineering and maritime organisation specialising in the maintenance, repair, and overhaul of naval vessels. The site operates with a skilled workforce across mechanical, electrical, and...

Senior Full Stack Engineer | Up to £110K | One of the UK's fastest growing AI platforms | UK Remote | React/Node/TypeScript I am currently working with one of the fastest-scaling platforms in the creator economy which is a creator-first, AI-powered product that enables creators around the world to directly monetise their audiences. Every system you build will operate at serious global scale. 🎯...

Fire & Security PPM Engineer - Mon - Fri Excellent salary and benefits. Various locations across the UK. About us G4S is a global company operating across 120 countries, employing over 650,000 people across the world. You can find more about us here; https://www.g4s.com/en-gb We are at the forefront of the fire and security integrator market in the UK and have an enviable reputation for...

Principal Grafana Network Analytics Engineer Edinburgh, UK | Fully Remote (UK-based) Engineering | Cyber Security £95,000 & Benefits Ever wanted your dashboards to actually defend the internet? This role does exactly that. I’m recruiting on behalf of a high-growth cyber security technology company that protects some of the world’s most critical online services from large-scale DDoS and...

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...

You will own the engineering vision and execution of Keepnet’s core platform, operating across the UK, EU, US, UAE, and Canada, supported by distributed offshore and nearshore teams.

You will not be expected to do everything yourself. Success in this role will be measured by platform reliability, delivery predictability, team health, and customer impact.

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...