Senior Software Engineer (C# / .NET)

Sage; Manchester; Hybrid; GBP 50,000 - 70,000; Full time

Job summary

A technology firm in Manchester seeks a Senior Software Engineer to develop scalable backend services using .NET and lead technical discussions. This hybrid role involves mentoring junior engineers and requires strong backend development skills and experience with Agile methodologies. The successful candidate will enjoy a collaborative environment focused on innovation and professional growth.

Benefits

Comprehensive health, dental and vision coverage

Work away scheme for up to 10 weeks a year

On-going training and professional development

Paid 5 days yearly to volunteer through our Sage Foundation

Flexible work patterns

Qualifications

• Strong commercial experience developing backend services with .NET (C#).
• Proven ability to design and implement RESTful APIs.
• Deep understanding of backend architecture, scalability, and performance.

Responsibilities

• Design and develop scalable .NET RESTful APIs.
• Lead backend architecture discussions and drive technical decisions.
• Mentor and coach junior engineers.

Skills

Backend services development

RESTful APIs design

Mentoring junior developers

Agile methodologies

Cross-functional collaboration

Tools

Docker

AWS

MySQL

Job description

Job Title

Senior Software Engineer (C# / .NET)

Job Description

We're looking for a Senior Software Engineer to join our team and play a key role in building and maintaining robust backend services that power the Sage platform. You'll work with .NET C#, MySQL, Docker, and AWS to deliver high-quality, scalable solutions that support our long-term business goals. This role is ideal for an experienced backend engineer who enjoys solving complex problems, leading development efforts, and mentoring junior engineers.

This is a hybrid role requiring 3 days per week in our Manchester office.

Your First 90 Days

• 30 days - Get onboarded to our tech stack, architecture, and core services. Understand our backend domain, team processes, and the goals of the product.
• 60 days - Start leading the development of key backend features and APIs. Collaborate with product and cross‑functional teams to shape solutions that are flexible and extensible.
• 90 days - Take ownership of critical services. Provide technical leadership in architecture discussions, contribute to process improvements, and mentor junior team members.

What You'll Do

• Design, develop, and maintain scalable .NET RESTful API domain services
• Lead backend architecture discussions and drive technical decisions
• Collaborate early with product managers to shape flexible and robust features
• Mentor and coach junior engineers to support their development
• Automate repetitive tasks using appropriate tools and scripting
• Keep technical documentation up to date and ensure high‑quality standards
• Promote and apply Agile development methodologies, including TDD and BDD
• Partner with cross‑functional teams across product, QA, and UX to ensure alignment
• Contribute to a culture of innovation, execution, and technical excellence
• Stay updated on emerging technologies, especially in cloud and AI domains

Meet the Team

You'll report to an Engineering Team Lead and work closely with other backend engineers, product managers, QA, and UX teams. The team is highly collaborative, technically strong, and focused on building performant and maintainable backend services that power mission‑critical business systems.

How Success Will Be Measured

• Delivery of reliable and scalable backend services
• Technical leadership and mentorship within the engineering team
• Effective collaboration across cross‑functional teams
• Continuous improvement of performance, quality, and developer experience
• Contribution to innovation, automation, and architectural excellence

Skills You’ll Gain

• Advanced expertise in backend engineering with .NET, Docker, and cloud infrastructure
• Experience shaping backend architecture and mentoring developers
• Exposure to AI‑related integrations and modern software development practices
• Deeper collaboration and leadership skills within an Agile organisation

Key Responsibilities

Snapshot of Your Day‑to‑Day

You'll spend your time designing APIs, coding in .NET, reviewing pull requests, and mentoring peers. You'll collaborate with product and QA teams, write automated tests, improve backend performance, and contribute to ongoing architectural discussions.

Qualifications

• Strong commercial experience developing backend services with .NET (C#)
• Proven ability to design and implement RESTful APIs
• Deep understanding of backend architecture, scalability, and performance
• Experience with Agile methodologies, including SCRUM and TDD / BDD
• Demonstrated ability to mentor and support junior developers
• Strong communication skills and cross‑functional collaboration experience
• Experience with MySQL or other relational databases

Nice to Have

• Hands‑on experience with Docker and AWS
• Background in building software that integrates AI components
• Familiarity with scripting and automation tools
• Interest in driving technical innovation and continuous improvement

At Sage, we offer you an environment where you can grow professionally without compromising your personal well‑being. Our benefits package is designed to provide stability, flexibility, and balance:

• Benefits video - https://youtu.be/TCMtTYUUiuU
• Comprehensive health, dental and vision coverage
• Work away scheme for up to 10 weeks a year
• On‑going training and professional development
• Paid 5 days yearly to volunteer through our Sage Foundation
• Flexible work patterns and hybrid working

Advert

Working at Sage means you're supporting millions of small and medium sized businesses globally with technology to work faster and smarter. We leverage the future of AI, meaning business owners spend less time doing routine tasks, like entering invoices and generating reports, and more time pursuing their ambitions.

Our colleagues are the best of the best. It's why we were awarded 2024 Best Places to Work by Glassdoor. Because to achieve extraordinary outcomes, we need extraordinary teams. This means infusing Sage with people who knock down barriers, continuously innovate, and want to experience their potential.

Learn more about working at Sage: sage.com/en-gb/company/careers/working-at-sage/

Watch a video about our culture: youtube.com/watch?v=qIoiCpZH-QE

We celebrate individuality and welcome you to join us if you embrace all backgrounds, identities, beliefs, and ways of working. If you need support applying, reach out at [e-mail] .

Learn more about DEI at Sage: sage.com/en-gb/company/careers/diversity-equity-and-inclusion/

Function

Product Delivery

Country

United Kingdom

Office Location

Manchester

Work Place type

Hybrid