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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Developer - **Company:** Commercial Ltd - **Location:** Cheltenham, UK - **Experience:** Expert - **Salary:** £60,000.0 - £65,000.0 - **Contract:** Permanent contract - **Skills:** ASP.NET, .NET Framework, Application Programming Interfaces (APIs), Artificial Intelligence, Business Software, Business Systems, C Sharp (Programming Language), Cloud Computing, Data Integrity, Extract Transform Load (ETL), Database Design, Electronic Data Interchange (EDI), Middleware, Microsoft Software, Microsoft SQL Server, Performance Tuning, Systems Development Life Cycle, Query Optimization, Release Management, Standard Sql, Software Engineering, Data Streaming, Systems Integration, Database Optimization, Database Performance, Usage Tracking, Web Technologies, Software Version Control, Legacy Systems - **Published:** August 14, 2026 - **Apply:** https://www.adzuna.co.uk/jobs/details/5841743347 ## About the Role * We have strong experience in software development using Microsoft technologies, including C#, .NET, and SQL Server. * We have solid understanding of the full development lifecycle, including support and continuous improvement. * We have proven expertise in SQL Server, including performance tuning, database design, and query optimisation. * We have experience with integrations, APIs, middleware, and data flows such as ETL, transformation, and mapping. * We can troubleshoot complex system and data issues across interconnected platforms. * We have a good understanding of development best practices, including source control, testing, and structured troubleshooting. * Exposure to business systems such as ERP or CRM, cloud platforms, or web technologies is beneficial. * We have a strong problem-solving mindset with a focus on improving systems and user experience. * We are well organised and able to manage priorities in a fast-paced environment. * We are confident communicators who work collaboratively and contribute positively to team culture. * We have awareness or interest in AI, automation, or emerging technologies, with a practical approach to applying them to real business challenges. ## Description * We develop, maintain, and enhance business applications, integrations, and internal systems, ensuring solutions are scalable, reliable, and user-focused. * We work closely with stakeholders to understand requirements, provide technical guidance, and deliver pragmatic solutions aligned to business needs. * We support and improve existing systems by troubleshooting issues, optimising performance, and enhancing usability and stability. * We design and deliver system integrations, including APIs, middleware, and data exchange, ensuring robustness, security, and effective data flow between platforms. * We take ownership of database performance, including schema design, query optimisation, indexing strategies, and data integrity. * We manage and support data processes such as imports, exports, transformation, and reconciliation across multiple systems. * We contribute across the full development lifecycle, including design, development, testing, deployment, and ongoing support. * We support release management, version control, and deployment processes to ensure controlled and stable system changes. * We collaborate with internal teams and third-party suppliers to ensure systems and integrations operate effectively. * We contribute to continuous improvement by modernising legacy systems and adopting best practice development approaches. * We explore and implement opportunities to leverage AI and automation technologies to improve system efficiency, data usage, and business processes, ensuring solutions are practical, secure, and aligned with business needs. 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