Senior Software Engineer

Senior Software Engineer - Abingdon, Oxfordshire – Permanent

Hybrid 3 days on site, 2 days remote

Required: - 5+ years of professional software engineering building & shipping complex, production-grade applications — not solely scripting, prototyping, or research. Strong proficiency in C#/.NET; & also, C/C++; demonstrated ability to work across both languages in a single product ecosystem. Undergraduate (or higher) degree in Computer Science, Software Engineering, or a closely related engineering discipline. Eclipse RCP is essential. Comfort & curiosity with AI-assisted development tools & a track record of staying ahead of technology trends. Experience with cloud architecture (AWS, Azure, &/or Google Cloud). Proven experience with software engineering fundamentals: object-oriented & component-based design, design patterns, unit/integration testing, version control (Git), & code review workflows. Hands-on CI/CD experience — building, configuring, or maintaining automated build & deployment pipelines. Experience modernizing legacy software — migrating codebases from older languages or frameworks to current platforms, including UI/UX modernization.

Senior Software Engineer Job Duties

This is a hands-on software engineering role. My client is looking to recruit an experienced Senior Software Engineer to design, develop, & modernize high-performance Rock Physics desktop & cloud applications. Reporting to the Team Lead & working closely with the Product Owner, you will own the technical direction of production software — writing code daily, reviewing pull requests, & driving architectural decisions.

Senior Software Engineer Key Responsibilities

• Design & build software — Architect, implement, & maintain complex desktop & cloud applications using modern software engineering practices (design patterns, SOLID principles, automated testing, continuous integration/delivery).
• Modernize legacy systems — Lead migration of mature C/C++ codebases to modern languages, runtimes, & UI/UX frameworks while preserving scientific accuracy & performance.

• Leverage AI-assisted development — Actively adopt AI-powered tools (e.g., Copilot, code-generation, automated testing assistants) to accelerate delivery & improve code quality.
• Collaborate on architecture — Partner with the Team Lead & Product Owner to translate requirements into sound, maintainable technical solutions the team can implement & iterate on.

• Mentor & lead technically — Coach junior & mid-level developers through code reviews, pair programming, & knowledge-sharing; foster a culture of engineering excellence.
• Communicate clearly — Escalate risks, trade-offs, & progress in a timely, structured manner to technical & non-technical stakeholders.
• Stay current — Continuously evaluate & adopt emerging languages, frameworks, cloud services, & AI/ML tooling relevant to the product.

 Self-motivated & collaborative; thrives in a team environment & takes initiative without direction. Excellent analytical, communication, & problem-solving skills.




With over 90 years' combined experience, NES Fircroft (NES) is proud to be the world's leading engineering staffing provider spanning the Oil & Gas, Power & Renewables, Chemicals, Construction & Infrastructure, Life Sciences, Mining and Manufacturing sectors worldwide. With more than 80 offices in 45 countries, we are able to provide our clients with the engineering and technical expertise they need, wherever and whenever it is needed. We offer contractors far more than a traditional recruitment service, supporting with everything from securing visas and work permits, to providing market-leading benefits packages and accommodation, ensuring they are safely and compliantly able to support our clients.