At a Glance
- Tasks: Design and build secure software products that enhance performance and decision-making.
- Company: Join Assystem, a leading nuclear engineering firm with a global presence.
- Benefits: Enjoy hybrid working, flexible hours, competitive salary, and generous leave options.
- Other info: Be part of a dynamic team driving digital transformation across the organisation.
- Why this job: Make a real impact on critical infrastructure projects while advancing your career.
- Qualifications: Experience in software development, API design, and collaborative teamwork.
The predicted salary is between 60000 - 80000 £ per year.
Today, Assystem is among the top three independent nuclear engineering firms worldwide. With over 60 years of experience in highly regulated sectors, the group supports public and industrial stakeholders in the execution of complex and strategic infrastructure projects, subject to high safety and security requirements. Assystem mobilizes 8,000 experts in 13 countries and intervenes across the entire project lifecycle, in engineering, project management and digital solutions. In line with our 2030 Business Plan, we are delivering a major enterprise transformation initiative—the Assystem Transformation Programme (ATP)—to streamline and harmonise business operations across all geographies.
The Job Mission
We are looking for a Senior Software Engineer to join the Digital Excellence Centre (DEC) UK. You will help design, build and support secure, maintainable software products and reusable components that improve performance, decision‑making and delivery across the business and for our clients. This is a hands‑on role in a small, senior team, with real scope to influence technical direction, engineering standards and solution design. You will work across a varied technology environment, contribute from discovery through to production support, and collaborate closely with colleagues in the UK, India and, where relevant, France.
What you will do:
- Work closely with senior stakeholders to understand requirements
- Design, build, test, deploy and support software applications, services and reusable components
- Produce pragmatic technical designs that balance quality, security and maintainability
- Work across back‑end services, integrations and user‑facing applications
- Contribute to engineering standards through code review, testing, CI/CD and documentation
- Design secure APIs and integrations across digital products, enterprise systems and data services
- Work closely with data engineers on APIs, events and data contracts
- Support and mentor others through pairing, review and day‑to‑day collaboration
- Help make sensible technology choices that keep solutions supportable over time
Qualifications:
- Practical use of, or strong interest in use of AI‑assisted development tools in a responsible delivery environment
- Experience delivering production software end to end, working closely with stakeholders
- Experience designing APIs and integrating with enterprise systems and data services
- Good understanding of software design principles and modern engineering practice
- Experience with automated testing and CI/CD
- Experience working with relational databases
- Familiarity with database and caching technologies
- Understanding of secure coding and modern authentication and authorisation
- Experience delivering software in cloud‑hosted environments, e.g., Azure
- Ability to work effectively across a mixed technology estate
- Strong communication skills and experience working in collaborative teams
- Experience mentoring others through review, pairing and practical support
- Experience with container tooling
- Familiarity with Microsoft tooling, including Power Platform
- Experience with Office document automation, including Excel, Word and PDF generation
Security and eligibility:
Depending on project requirements, you may need to meet UK residency criteria and achieve UK security clearance, such as BPSS and potentially SC.
Additional Information:
You do not need deep expertise in all of these, but you should be comfortable learning and contributing across a varied environment. Our current stack includes, but is not limited to: C#/.NET, SPython/FastAPI/Django, TypeScript, Angular, Vue.js, PostgreSQL, MongoDB, Redis/Valkey, RabbitMQ, Kafka, Azure, S3‑compatible storage, Talend, NiFi, Docker, Podman, Kubernetes, Power Platform and Office document automation tools such as Aspose.
Join Assystem and play a key role in delivering enterprise‑wide digital transformation across a global engineering organisation. Work alongside highly experienced software and data professionals to build innovative solutions supporting critical infrastructure projects while developing your career in a collaborative and forward‑thinking environment.
Benefits:
- Hybrid Working Opportunity
- Flexible working hours
- Pension scheme (8% company contribution / 4% personal contribution)
- 25 days’ paid annual leave + bank holidays + option to buy or sell days
- Professional fees reimbursed
- Employee referral scheme
- Competitive Sick Pay – Support when you need it
- Income Protection
Senior Software Engineer — Hybrid, Build Secure APIs & Apps employer: Assystem
Assystem is an exceptional employer, offering a dynamic and collaborative work environment where Senior Software Engineers can thrive. With a strong focus on employee growth, the company provides opportunities to influence technical direction while working on innovative projects that support critical infrastructure. The hybrid working model, flexible hours, and comprehensive benefits package, including a generous pension scheme and professional development support, make Assystem a rewarding place to advance your career.
