Senior Software Engineer (Contract)

Digital Waffle; United Kingdom; Remote; GBP 50,000 - 70,000; Full time

Job summary

A tech consultancy is seeking a Senior Software Engineer (Contract) to enhance application and infrastructure performance. This fully remote position requires expertise in .NET, SQL Server, and performance tuning. Key responsibilities include analyzing .NET efficiency, optimizing database performance, and collaborating on telemetry improvements. Familiarity with tools like K6, Playwright, and Azure DevOps is essential. The ideal candidate is proactive and translates complex findings into actionable recommendations. Competitive compensation is offered.

Qualifications

• Hands-on expertise with .NET (C#), async programming, concurrency, and memory management.
• SQL Server query tuning and indexing.
• Familiarity with modern observability and testing tools.

Responsibilities

• Analyze .NET applications for efficiency, memory usage, and concurrency.
• Optimize SQL queries, indexes, and overall database performance.
• Expand and refine telemetry across the stack.

Skills

DOM performance

MS SQL Server

K6

Playwright

Azure DevOps

Job description

Role: Senior Software Engineer (Contract)

Location: Fully Remote (UK)

We’re looking for an experienced Senior Software Engineer (Contract) to join on an interim basis and drive performance improvements across our applications and infrastructure. You’ll be responsible for identifying bottlenecks, putting the right telemetry in place, and helping our teams deliver a faster, more reliable experience for customers at scale.

Key Must Have Skills

• DOM performance
• MS SQL Server, query optimisation, and indexing strategies
• K6, Playwright, AppInsights
• Azure DevOps - CI/CD pipelines and observability tooling

What you’ll be doing

• Backend performance: Analyse .NET applications for efficiency, memory usage, and concurrency, implementing improvements where needed.
• Database tuning: Optimise SQL queries, indexes, and overall database performance.
• Instrumentation & monitoring: Expand and refine telemetry across the stack using tools such as AppInsights, K6, and Playwright.
• Collaboration: Partner with engineers, testers, and product teams to prioritise performance initiatives, share best practices, and influence long-term improvements.
• Load testing: Support the design and execution of realistic load/performance scenarios to uncover weaknesses and recommend fixes.

What we’re looking for

• Hands-on expertise with:
• .NET (C#), async programming, concurrency, and memory management.
• SQL Server query tuning and indexing.
• Familiarity with modern observability and testing tools (e.g. K6, Playwright, AppInsights, Azure DevOps).
• Good knowledge of CI/CD practices and performance instrumentation.
• Clear communicator, able to turn complex technical findings into actionable recommendations.
• Independent, proactive, and delivery-focused.

Nice to have

• Experience working with Vue.js or other modern front-end frameworks.