Senior .NET Software Engineer

Business Insurance Solutions Ltd (Van Compare and Business Compare); Greater London; On-site; GBP 75,000 - 80,000; Full time

Job summary

Business Insurance Solutions Ltd (Van Compare and Business Compare) seeks a skilled .NET engineer to modernize and support a portfolio of legacy applications and services. You will refactor and/or re-architect them for long-term stability, working across the full development lifecycle with UK/India collaboration. Salary is £75,000–£80,000 per year.

The role emphasizes hands-on coding, problem solving, and delivering quality software while mentoring colleagues and improving systems.

Qualifications

• Proficiency in C# and .NET, including migration to modern versions.
• Experience with SQL Server (T-SQL) and PostgreSQL; design and optimization.
• Cloud-based development, ideally AWS (EC2, RDS, Lambda, S3).
• CI/CD with TeamCity and Octopus Deploy (or equivalent).
• GitHub for version control and PRs.
• Unit and integration testing with xUnit.
• SOLID and clean architecture principles.
• Ability to modernize legacy systems.
• Containerization with Docker; Kubernetes experience desirable.
• Experience with microservices and event-driven architectures desirable.
• Monitoring/logging with CloudWatch, ELK, Grafana desirable.
• Agile and DevOps practices desirable.
• Comfort with legacy and modern tech.
• Strong documentation and communication.
• Mentoring peers and proactive improvements.
• Detail-oriented and maintainable coding.

Responsibilities

• Upgrade and modernize legacy .NET apps to .NET 6/8/10.
• Analyze codebases to identify risks and improvements.
• Collaborate with stakeholders to translate needs into technical solutions.
• Work with MSSQL and PostgreSQL ensuring data integrity and tuning.
• Integrate with AWS cloud services and follow scalable, secure practices.
• Use GitHub for PRs and collaboration.
• Build, release, and deploy via TeamCity and Octopus Deploy.
• Write clean, tested code with unit/integration tests.
• Maintain monitoring and alerting systems.
• Provide ongoing support and troubleshooting.

Skills

C# & .NET

Agile methodologies

Problem solving

Documentation

Tools

AWS

Lambda

GitHub

TeamCity

Octopus Deploy

Docker

Kubernetes

CloudWatch

ELK

Grafana

PostgreSQL

SQL Server

Job description

Salary: £75,000 - 80,000 per year

Requirements:

• Strong experience with C# and .NET, including migration to modern .NET Core/.NET versions, and building systems such as web APIs and background services using technologies such as HTTP, JSON, XML and message brokers.
• Proficiency in SQL Server (T-SQL) and PostgreSQL – schema design, stored procedures, performance optimization.
• Familiarity with cloud-based development and deployment, ideally in AWS (EC2, RDS, Lambda, S3, etc.).
• Experience with CI/CD pipelines and automated deployments using TeamCity and Octopus Deploy (or equivalent services).
• Version control expertise with GitHub (branching strategies, pull requests, code reviews).
• Ability to develop integration and unit tests with tools such as xUnit, and knowledge of when to use either type of test.
• Good understanding of software design principles (SOLID, clean architecture, layered design).
• Proven ability to work with legacy systems and progressively modernize them.
• Knowledge of containerization (Docker, ECS, or Kubernetes in AWS) – desirable.
• Familiarity with microservices and event-driven architectures – desirable.
• Experience with monitoring and logging solutions (e.g., CloudWatch, ELK stack, Grafana) – desirable.
• Exposure to Agile methodologies and DevOps practices – desirable.
• Comfortable working with both legacy and modern technologies.
• Good written and verbal skills with the ability to clearly document and explain business processes and solution designs.
• Able to work well in a small team either with peers or mentoring less experienced colleagues.
• Proactive in identifying improvements to codebases, processes, and systems.
• Detail-oriented with a focus on writing reliable and maintainable software.

Responsibilities:

• Upgrade, refactor, and modernize legacy .NET applications, web APIs and services to supported frameworks (.NET 6/8/10).
• Analyse existing codebases to identify risks, dependencies, and opportunities for improvement.
• Collaborate with stakeholders to understand business needs and translate them into technical solutions.
• Work with both SQL Server (MSSQL) and PostgreSQL databases, ensuring data integrity and performance tuning.
• Integrate with and deploy to AWS cloud services, leveraging best practices in scalability, security, and reliability.
• Use GitHub for version control and collaborative development workflows (PRs, code reviews).
• Build, release, and deploy applications via TeamCity and Octopus Deploy.
• Write clean, maintainable, and well-documented code with appropriate unit or integration tests, in a test-driven manner where appropriate.
• Maintain and enhance our monitoring and alerting systems to ensure rapid response to production incidents.
• Provide ongoing support and troubleshooting for applications, ensuring minimal downtime and performance issues.

Technologies:

• AWS
• Lambda
• C#
• CI/CD
• Cloud
• CloudWatch
• DevOps
• Docker
• EC2
• ELK
• GitHub
• Grafana
• HTTP
• Support
• JSON
• Kubernetes
• LESS
• PostgreSQL
• SQL
• Security
• Teamcity
• Web
• XML
• microservices
• ASP.NET

More:

We are seeking a skilled .NET engineer to modernize and support our portfolio of legacy applications and services. Many of our existing systems are built on older, unsupported .NET versions, and you will play a key role in refactoring and/or re-architecting and future-proofing them for long-term stability. This is a hands-on role that requires strong problem-solving skills, a solid understanding of enterprise application design, and experience working across the full development lifecycle. Working alongside colleagues in both the UK and India, you will be part of a team that collaborates closely with the commercial side of the business. If you enjoy building systems using the .NET platform, with a focus on delivering quality software whilst continuing to learn and improve with colleagues, then this is an excellent opportunity to further your career. The salary range for this position is £75,000 – £80,000 per year.

last updated 40 week of 2026