Senior Software Engineer

ScaleX™ Talent Solutions; Chippenham; On-site; GBP 90,000 - 110,000; Full time

Job summary

ScaleX™ Talent Solutions is seeking an experienced Senior C#/.NET Developer to join a small technical team delivering a two-part platform: an HMI web app (ASP.NET Core, Blazor WebAssembly) and a cloud-enabled customer portal with Azure services.

You will own hands-on development, implement secure, reliable software for real-world environments, and contribute to delivery without moving into management.

Qualifications

• Senior-level commercial experience with C# and modern .NET.
• Production experience with Blazor WebAssembly.
• Strong component design and state-management knowledge.
• Experience designing applications that tolerate intermittent server connectivity.
• ASP.NET Core experience, including web APIs & authentication.
• Experience with ASP.NET Core Identity.
• Experience hosting ASP.NET Core apps on Linux.
• Strong SQL Server and relational database knowledge.
• Experience integrating with external REST APIs and managing API version changes.
• Secure development practices: input validation, secrets handling, TLS & certificates.
• Automated testing and Git-based development workflows.

Responsibilities

• Building the HMI application across ASP.NET Core back end, Blazor WebAssembly front end and local database.
• Developing the customer portal and supporting Azure cloud services.
• Working on the machine gateway, integration API and background services.
• Implementing security features including certificates, mutual TLS, MFA and RBAC.
• Supporting signed software updates and security event logging.
• Writing automated tests, including end-to-end testing against a physical test machine.
• Reviewing code and ensuring the design and code remain aligned.
• Helping shape how the team develops, tests and releases software.

Skills

C#/.NET

Blazor WebAssembly

ASP.NET Core

REST APIs

Security & TLS

Automated testing

Git workflows

Tools

Azure

Linux hosting

Job description

This is not another software role where your work disappears into the background of a large platform.

You will be building the software that customers and operators use to control and monitor hydrogen fuel-cell generators in real-world environments.

We are partnering with an innovative clean energy business developing a range of hydrogen power systems capable of delivering between 110 kVA and 1,200 kVA. Each machine is controlled through an onboard Linux computer and connects to a cloud platform for monitoring, fleet management and software updates.

The business is now building the next generation of this software and is looking for an experienced Senior C#/.NET Developer to join a small technical team.

The opportunity

You will work across two connected parts of the platform:

• An HMI web application built with ASP.NET Core and a Blazor WebAssembly front end, used by operators directly on the machine and remotely through a VPN
• A cloud platform incorporating a Blazor WebAssembly customer portal, machine gateway, integration API and background services hosted on Microsoft Azure

The architecture is already designed and initial development is underway. This role is about getting hands-on, building out the platform and helping create secure, reliable software that works in demanding, real-world conditions.

This is not a move away from development into people management. We are looking for someone who still enjoys writing code, solving difficult technical problems and taking ownership of delivery.

What you will be doing

• Building the HMI application across its ASP.NET Core back end, Blazor WebAssembly front end and local database
• Developing the customer portal and supporting Azure cloud services
• Working on the machine gateway, integration API and background services
• Implementing security features including certificates, mutual TLS, multi-factor authentication and role-based access
• Supporting signed software updates and security event logging
• Writing automated tests, including end-to-end testing against a physical test machine
• Reviewing code and ensuring the design and code remain aligned
• Helping shape how the team develops, tests and releases software

What we are looking for

You should be able to demonstrate:

• Senior-level commercial experience with C# and modern .NET
• Production experience with Blazor WebAssembly
• Strong component design and state-management knowledge
• Experience designing applications that remain usable when server connectivity is interrupted
• ASP.NET Core experience, including web APIs and authentication
• Experience with ASP.NET Core Identity
• Experience hosting ASP.NET Core applications on Linux
• Strong SQL Server and relational database knowledge
• Experience integrating with external REST APIs and managing changes between API versions
• A secure approach to development, including input validation, secrets handling, TLS and certificates
• Automated testing and Git-based development workflows

Useful additional experience

Experience in any of the following would be valuable, but is not essential:

• Front Door or Application Gateway
• Managed identities
• MQTT or MQTTnet
• IEC 62443 or the EU Cyber Resilience Act
• Certified products or regulated software
• Energy, power generation, industrial equipment or connected machinery

Why consider it?

You will be joining a growing clean energy business where the software team works closely with the physical product.

You will be able to see how your work performs on a real machine, influence how the platform develops and contribute to technology designed to provide reliable power without relying on traditional diesel generators.

If you are an experienced C#/.NET Developer who wants to remain hands-on and build secure software with a genuine real-world application, we would be keen to hear from you.