Software Engineer | C# / .NET Core

Software Engineer | C# / .NET Core | SQL | Azure | APIs | Full stack Leaning | Fully Remote UK

Salary: £65,000 + excellent benefits

Contract: Permanent Start: ASAP

Working model: Fully Remote (UK-based) - office available in London if you want it

Eligibility: Only UK residents - No Sponsorship

Required: C# .NET Core, APIs, Azure, SQL Server, 5+ years commercial experience (Non-Negotiable)

🚨 Please only apply if you have ALL of the following 🚨

Core technologies:

• C# / .NET Core
• APIs and backend services
• Azure (Service Bus, Storage, KeyVault, etc.)
• SQL Server
• Containers
• Unit testing
• Agile / Scrum

Environment:

• Minimum 5 years commercial software development experience
• Comfortable owning features end-to-end across back-end and front-end
• Strong experience designing, building, and deploying production-ready systems
• Solid understanding of modern engineering practices and scalable architectures
• Logical problem-solver - pragmatic, ambitious, and a genuine team player

Key skills:

• Strong C# / .NET Core engineering
• Building and maintaining APIs and backend services
• Hands-on Azure experience across multiple services
• Strong SQL Server skills
• Experience with containerised environments
• High standards for code quality, testing, and reliability
• Excellent written and spoken English - clear, confident communicator

Role Overview

Optimal has partnered exclusively to hire a Software Engineer for a well-established, fast-paced tech company that handles millions of transactions every day across a broad customer base. You’ll be working on real-world, high-impact systems like back-end architectures, APIs, e-commerce, and customer-facing web apps that thousands of people depend on daily.

This is a hands-on full-stack-leaning role focused on scalable back-end engineering, with the flexibility to contribute to modern .NET front-end applications too. You'll work closely with Product, BAs, QA, and external partners to ship features that genuinely make a difference.

Key Responsibilities

• Engineer scalable back-end architectures and communication protocols to support mobile and web systems
• Build and maintain APIs, message processing, HTTP data interfaces, e-commerce, and supporting services
• Design, develop, and support feature-rich, modern, customer-facing .NET web applications
• Collaborate with Product Owners, BAs, QA, and external partners to understand and deliver quality features
• Take ownership of systems from design through deployment
• Contribute to architectural decisions and long-term technical direction
• Maintain high standards of code quality, testing, and documentation

Nice to Have

• High volume data processing experience
• Kubernetes
• gRPC
• Knowledge of architectural and design patterns
• Front-end skills (CSS/SCSS, HTML, JavaScript, TypeScript, Blazor)
• Security awareness

The Company

An established UK tech company operating at serious scale - millions of transactions processed every day, hundreds of customers across the UK, and growing internationally. Remote-first culture, strong engineering bar, real-world impact, and excellent benefits.

If you tick all the boxes and can start ASAP, we'd love to hear from you. We are moving fast on this one!