Senior Full Stack .NET Developer (Belfast, NI)

Biller Genie; Belfast; Hybrid; GBP 50,000 - 70,000; Full time

Job summary

A leading B2B SaaS platform company entering the Belfast market is seeking a Senior Full Stack .NET Developer. You will contribute significantly to the development of innovative solutions in a dynamic fintech environment. Key responsibilities include designing robust solutions and collaborating with senior engineers. Ideal candidates will have over 4 years in .NET with strong programming skills in C#, ASP.NET, and cloud technologies. We offer professional growth opportunities and a hybrid work environment.

Benefits

Private health insurance

Group life death benefit

Auto-enrollment pension with employer contributions matched to 5%

25 days holiday per year

10 statutory/bank holidays per year

Opportunities for professional growth and development

Collaborative and innovative work environment

Qualifications

• 4+ years of hands-on experience programming on the .NET platform using C#.
• Experience with Design Patterns and OO Design.
• Strong communication skills.

Responsibilities

• Design & build solutions to meet business needs.
• Work with senior engineers to develop solutions from idea to implementation.
• Gather requirements and release software in a timely fashion.

Skills

C#

ASP.NET

HTML

JavaScript

CSS

SQL

Problem-solving

Cloud technologies (Azure/AWS/GCP)

Education

BSc or MSc in Computer Science or related qualification

Tools

Source control tools (TFS, SVN, GIT)

Job description

Job Title: Senior Full Stack .NET Developer

Location: Belfast, Northern Ireland

Work Arrangement: Hybrid (In-Office)

About Us

Ranked #259 on the Inc. 5000 fastest growing companies in the United States, in 2023, and sustaining that with #482 in 2024. Biller Genie is an award‑winning B2B SaaS platform that is entering the Belfast market with ambitious plans to scale our team rapidly, with over 100 hires planned through 2026.

We are looking for a Senior Full-Stack .NET Developer who can quickly understand our existing codebase and significantly contribute to the development of complex, innovative solutions in our fast‑paced fintech environment. As a key member of our production team, you will take ownership of significant features, driving them from conception to deployment. We need a versatile "Swiss Army Knife"—a developer who is comfortable across the entire SDLC, from architectural design and implementation to testing and deployment. Your experience and expertise will be vital in delivering high‑quality, robust solutions.

Primary Job Responsibilities

• Design & build future‑proof solutions to support growing business needs while thoroughly considering the system impact
• Work closely with senior engineers to develop solutions from idea to implementation by estimating, planning, tracking and managing progress, risks, and dependencies
• Gather and refine requirements, and release software in a timely fashion
• Be adaptive and strike a good balance between speed and efficiency
• Work with the technical support team to identify, reproduce, and remediate bug tickets
• Perform other duties required by Management

Essential Criteria

• BSc or MSc in Computer Science / related qualification OR commercial experience of developing in C#, Java or other OO programming languages
• Minimum 4+ years of hands‑on experience programming on the .NET platform using C#, including ASP.NET (MVC)
• Experience with Design Patterns, refactoring, OO Design and related areas
• Exposure to building web services using Web API
• An understanding of database design and development
• Hands‑on experience with HTML, JavaScript, CSS including jQuery
• Strong attention to detail and work ethic
• Strong analytical and problem‑solving skills
• Excellent communication (both written and verbal) and interpersonal skills
• Experience of cloud technologies such as Azure/AWS/GCP
• Previous experience working with source control tools (TFS, SVN, or GIT)
• Legal right to work in the UK

Desirable Criteria

• Experience with Azure Functions and Queues
• Experience in testing methodologies
• Experience of LEAN software development practices
• Knowledge of CI/CD systems and implementation practices
• Hands‑on experience with front‑end frameworks such as Bootstrap
• Knowledge on .NET Core and Entity framework Code First migrations
• Experience in Financial services industry

What We Offer

• Private health insurance
• Group life death benefit
• Auto‑enrollment pension with employer contributions matched to 5%
• 25 days holiday per year
• 10 statutory/bank holidays per year
• Opportunities for professional growth and development
• A collaborative and innovative work environment

Our Mission

To provide an automated A/R platform that seamlessly integrates existing business processes for the SMB market.

Our Core Values

Get Shit Done Right – We work hard and ensure tasks are completed correctly and on time, every time.

Own it – We are subject matter experts who know what we know, and we are confident enough to speak up when we see something wrong.

Catch Up – We are high performers and love a fast‑paced environment.

Believe in the Genie – We are passionate about where we are going as a team, and we show we care.

Class Shines – We are articulate professionals who carry ourselves well and speak with purpose.

Please note we are unable to offer visa sponsorship.