Lead Full Stack .NET Developer (Belfast, NI)

Biller Genie; Belfast; Hybrid; GBP 60,000 - 80,000; Full time

Job summary

A dynamic fintech company in Belfast is seeking a Lead Full Stack .NET Developer to provide architectural vision and lead the development team. The role requires extensive experience in .NET with a focus on C# and cloud technologies. Ideal candidates will have strong problem-solving skills and a history of mentoring engineers. The position offers hybrid work and comprehensive benefits including health insurance and professional growth opportunities.

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

• 7+ years of experience programming on the .NET platform using C#.
• Experience with Design Patterns and OO Design.
• Hands-on experience with HTML, JavaScript, and CSS.
• Strong analytical and problem-solving skills.
• Excellent written and verbal communication skills.

Responsibilities

• Design & build future-proof solutions for business needs.
• Mentor and lead engineers from idea to implementation.
• Gather and refine requirements for timely software releases.
• Work with technical support to remediate bug tickets.
• Perform other duties as required by management.

Skills

C#

.NET platform

ASP.NET (MVC)

HTML

JavaScript

CSS

Design Patterns

problem-solving skills

communication skills

cloud technologies

Education

BSc or MSc in Computer Science or related qualification

Tools

SQL Databases

Azure

TFS, SVN, GIT

Job description

Job Title: Lead Full Stack .NET Developer

Location: Belfast, Northern Ireland

Work Arrangement: Hybrid (In-Office)

We are seeking a Lead Full-Stack .NET Developer to provide architectural vision and strategic direction, guiding our team in efficiently understanding and extending our codebase. In this pivotal role, you will collaborate closely with Product and Engineering leadership to deliver innovative, scalable solutions in a dynamic fintech environment. As a technical leader, you’ll embody the 'Swiss Army Knife' ethos—excelling in all phases of the SDLC, from defining high-level architecture and future‑proofing designs to hands‑on development, mentoring, and ensuring code quality. Your expertise will be crucial in shaping our technical roadmap and driving our team to deliver exceptional results. Join us and lead the charge in building the future of fintech!

About Us

Recently ranked #259 on the Inc. 5000 fastest growing companies in the United States, 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.

Primary Job Responsibilities

• Design & build future‑proof solutions to support growing business needs while thoroughly considering the system impact
• Mentor and lead our 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 our 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 7+ years of hands‑on experience programming on the .NET platform using C#, including ASP.NET (MVC)
• Expertise with Design Patterns, refactoring, OO Design and related areas
• Experience in Web API design principles and best practices
• Comfortable with 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)
• Experience leading / mentoring a small team of Engineers in all aspects of product development
• Legal right to work in the UK

Desirable Criteria

• Experience with Azure Functions and Queues
• Hold a Cloud certification
• Experience in testing methodologies
• Experience in Financial services industry
• 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

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.