Lead Software Engineer

About the role

Masson Appointments Ltd is seeking a Lead Software Engineer to work directly with the founders on high‑impact client projects across aviation, transport and other industries. This hands‑on, senior‑level position will involve designing scalable architectures, building clean APIs and cloud infrastructure, and taking full ownership of production systems.

Key responsibilities

• Mentor and coach developers, set engineering standards and lead technical decisions.
• Own technical direction and architecture for client projects, including domain modelling and service design.
• Design, develop and maintain REST APIs and backend services in C#/.NET.
• Integrate with external HR platforms, asset management tools, data warehouses and messaging systems.
• Write and optimise SQL queries, design database schemas and ensure data integrity.
• Establish and enforce engineering best practices: code review, testing, CI/CD and conventions.
• Work daily with Azure services such as Functions, App Service, Service Bus, Blob Storage and Key Vault.
• Contribute to hiring, onboarding and the technical growth of the team.
• Support production systems and guarantee reliability.

Required profile

• Proven senior‑level experience in C# and .NET development.
• Strong background in designing and delivering enterprise‑grade APIs.
• Experience mentoring developers and raising engineering standards.
• Ability to own end‑to‑end delivery of complex, cloud‑based solutions.

Required skills

• C# on .NET
• ASP.NET Core (Web API)
• Azure Functions (isolated worker)
• SQL Server, Entity Framework Core, Dapper
• Microsoft Azure (Functions, App Service, Service Bus, Blob Storage, Key Vault, AKS)
• Microsoft Dataverse integration
• Entra ID (Azure AD) and OAuth 2.0
• Azure DevOps CI/CD pipelines
• Docker and Azure Container Registry