Senior Backend Engineer (.NET)

Benifex Limited; Southampton; Hybrid; GBP 75,000 - 90,000; Full time

Benefits offered by this job

Salary £75k-£90k

Tech setup

Learning budget

Flexible work

Benefits package

25 days holiday

Birthday off

Wellbeing days

Healthcare cash plan

Employee Assistance

Income protection

Parental leave

Work from Anywhere

Holiday Buy/Sell

Benifex card

Job summary

Benifex Limited in the United Kingdom seeks a Senior .NET developer to shape the future of our Benefits platform. You will lead backend design, work with Product and Engineering, and help scale services with modern patterns.

The role emphasizes microservices, Kubernetes, CI/CD, and cloud-native practices, with a competitive package and UK-based office flexibility. You will join a fast-growing team with strong learning budgets and wellbeing benefits.

Qualifications

• Extensive backend experience with C#.NET and .NET Core.
• Knowledge of Kubernetes and containerisation for modern infra.
• Experience with microservices, CQRS and event-driven patterns.
• Experience with Pub/Sub, distributed transactions, and Redis caching.
• Ability to set up and maintain CI/CD pipelines.
• Understanding of performance, debugging, and optimization.
• Collaborative with remote teams including Java Spring Boot engineers.

Responsibilities

• Lead the design and development of scalable backend solutions for our Benefits product using C#.NET and .NET Core.
• Collaborate with Product and Engineering teams to define technical requirements, ensure delivery, and drive architectural decisions.
• Modernise systems by introducing microservices, containerisation (Kubernetes), and cloud-native practices.
• Implement and maintain CI/CD pipelines to ensure seamless deployment and delivery processes.
• Advocate for and implement best practices in coding, architecture, and process.
• Work effectively with remote teams to deliver cohesive and robust solutions.
• Collaborate with Java Spring Boot engineers to ensure seamless integration.

Skills

C#.NET

NET Core

Kubernetes

CI/CD

Microservices

Event-driven

Pub/Sub

Redis

Cloud

Observability

Tools

GCP

MSMQ

Pub/Sub

Redis

Terraform

Job description

Who are Benifex?

We are a fast-moving technology company, and one of the most successful providers of online reward and benefits solutions in the world. We believe that everyone deserves an exceptional experience at work, every day, and build workplace technology that makes this happen. Benifex’s mission is to build remarkable experiences that employees love. Today Benifex supports more than five million employees in over 3,000 organisations across more than 100 countries. To help us on our quest to be the best, we need brilliant people on board and that’s where you come in.

Why should you apply?

• Impact: AI first by default, we’re building our SDLC around AI Assisted engineering and you’ll be part of shaping this.
• Technology: Gain experience working with cutting-edge technologies and architectural practice on a product used by millions.
• Team: Work with a talented, experience group of engineers dedicated to building high quality product for our users.
• Sunday Times Best Place to Work 2025 and Best Large Tech Company to Work for 2025
• Work for a profitable, fast-growing market leader in the online reward and benefits space

Role Overview

Our Engineering department is looking for Senior .Net developers to help shape the future of our platform and engineering department! We are going through a key period of growth across the business and have roles within existing teams delivering key functionality, as well as brand new teams set up to achieve our goals as a business.

Please note we are unable to offer visa sponsorship and require to people to be based in the UK or Ireland for this position

Great benefits

• £75,000-90,000
• Tech setup of your choice (MacBook Pro or equivalent, monitors, etc.)
• £/€800 annual learning budget, plus two hours per week as ‘Focus Fridays’.
• Flexible work – choose a working setup that works for you, our only ask is to see you once a month in the office and you must be based in the UK or Ireland.
• Full access to our comprehensive benefits package, including discounts from hundreds of high street brands, salary sacrifice schemes across Finance, Health, Tech, and more
• 25 days holiday plus your local bank holidays
• Your birthday off
• Two half day wellbeing days
• Healthcare cash plan to cover the costs of day-to-day healthcare
• Employee Assistance Plan 24/7 365 support
• Income Protection (75%) and life assurance (4x salary)
• Referral bonuses
• Enhanced parental leave package - 26 weeks fully paid maternity leave and 4 weeks fully paid paternity leave
• Work from Anywhere policy for 90 days
• Buy and Sell scheme for holidays
• £50 monthly allowance to spend on whatever takes your fancy, your very own Benifex card will be topped up at the start of each month!

Responsibilities

• Lead the design and development of modern, scalable backend solutions for our Benefits product using C#.NET and .NET Core.
• Collaborate closely with Product and Engineering teams to define technical requirements, ensure high-quality delivery, and drive architectural decisions.
• Modernise existing systems by introducing microservices, containerisation (Kubernetes), and cloud-native practices.
• Implement and maintain CI/CD pipelines to ensure seamless deployment and delivery processes.
• Advocate for and implement best practices in coding, architecture, and process, ensuring a high standard of technical excellence.
• Work effectively with remote teams to deliver cohesive and robust solutions.
• Collaborate with engineers from Java Spring Boot backgrounds to ensure seamless integration and knowledge sharing.

Tech stack: .NET, SQL, GCP, MSMQ (moving to Google Pub/Sub), Kubernetes.

What are we looking for?

• Extensive experience in backend development with C#.NET and .NET Core, with a focus on scalable, maintainable solutions.
• Proven knowledge of Kubernetes and containerisation to support modern infrastructure practices.
• Experience with modern architectural patterns, including microservices, CQRS and event-driven systems. Bonus points for experience with circuit breaker, transient fault handling, outbox patterns, dead letter handling
• Hands‑on experience with messaging systems like Pub/Sub, distributed transaction coordination (MSDTC), and caching solutions like Redis.
• Proven ability to set up and maintain CI/CD pipelines to streamline development and deployment workflows.
• Solid understanding of system performance, optimisation, and debugging.
• Collaboration: Ability to work effectively with cross-functional and remote teams, including Java Spring Boot engineers, to deliver cohesive solutions.
• Proactive Problem‑Solving: A resourceful approach to tackling complex challenges and driving projects forward with minimal guidance.
• Technical Excellence: A strong advocate for clean code, best practices, and high-quality software development.

Bonus Points for:

• Experience with cloud technologies, particularly in deploying and scaling .NET applications.
• Familiarity with observability tools for monitoring, logging, and alerting (e.g., Grafana, Prometheus).
• Knowledge of IaC tools such as Terraform.
• Previous experience modernising legacy systems or transitioning monolithic architectures to microservices.

Our interview process

Benifex understands the need to have a fast and efficient process, the below will all be completed in the shortest time possible.

Initial informal call with the Talent team

Interview with our Engineering Manager 30 min

Technical Task

Technical Interview - 60 min

Final interview with VP of Engineering - 30-45 min

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

We are committed to creating a diverse and inclusive workplace where everyone feels welcome and respected. We believe that diversity and inclusion are essential to our success, and we are proud to be an equal opportunity employer.

We are a proud member of the Disability Confident employer scheme.

If you require any reasonable adjustments at any stage during the recruitment process, please let us know with your application.