Senior Software Engineer - Hybrid, Secure APIs & Cloud

Assystem UK Ltd; Bagstone; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Hybrid Working

Flexible working hours

Pension scheme (8% company / 4% лич)

25 days’ paid annual leave + bank hols

Professional fees reimbursed

Employee referral scheme

Sick pay

Income protection & 3x salary death-in

Death-in-Service Cover

Digital gym access

24/7 employee support line

Job summary

Assystem UK Ltd is seeking a Senior Software Engineer to join the Digital team. You will design, build, and support secure software products and reusable components across a varied tech stack, collaborating with colleagues in the UK, India, and France.

The role offers hands-on work in a senior team with influence on technical direction and engineering standards. You will contribute from discovery through production support, delivering APIs and integrations while mentoring others and advancing

Qualifications

• 8 years of professional software development experience.
• Experience delivering production software end to end and collaborating with stakeholders.
• Frontend and backend development experience.
• Experience designing APIs and integrating with enterprise systems.
• Strong understanding of software design principles and modern engineering practices.
• Experience with automated testing and CI/CD.
• Experience with relational databases and caching technologies.
• Understanding of secure coding and modern authentication and authorization.
• Experience delivering software in Azure or similar cloud environments.
• Ability to work effectively across a mixed technology estate.
• Strong communication and collaboration skills; mentoring others.
• Security clearance: UK residency criteria and possible BPSS/SC.

Responsibilities

• 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.

Skills

8 years experience

AI-assisted development

End-to-end delivery

Full stack

API design

Software design principles

Automated testing & CI/CD

Relational databases

Caching technologies

Secure coding & auth

Cloud environments (Azure)

Cross-functional collaboration

Security clearance eligibility (UK)

Tools

Container tooling

Power Platform

Office document automation (Excel/Word/PDF)

Job description

Assystem UK Ltd is seeking a Senior Software Engineer to join the Digital team. You will design, build, and support secure software products and reusable components across a varied tech stack, collaborating with colleagues in the UK, India, and France.

The role offers hands-on work in a senior team with influence on technical direction and engineering standards. You will contribute from discovery through production support, delivering APIs and integrations while mentoring others and advancing