.NET Backend Developer & Legacy System Modernisation Specialist

UK-based .NET Backend Developer • SQL Server • Sage 200 Integration • API Platforms

Focused on custom backend systems and integrations — no CMS or WordPress development.

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.NET, SQL Server & Sage 200 Services

Specialist contract delivery across backend development, database optimisation and enterprise integration.

.NET Backend Development

Design and build scalable backend systems using modern .NET architectures for high-demand business environments.

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SQL Server Optimisation

Advanced query tuning, stored procedure optimisation and high-volume data processing systems.

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Sage 200 Integration

End-to-end integration with Sage 200, ERP platforms and external systems via APIs and data sync pipelines.

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Integration Expertise

I specialise in connecting systems that were never designed to work together. From legacy platforms to modern APIs, I design integration layers that are reliable, maintainable and aligned with real business processes.

Anything to Anything Integration

Whether it is Sage 200, ecommerce platforms, internal systems or third-party APIs, I build robust data pipelines and service layers to connect them seamlessly.

API & Middleware Design

Designing clean API layers and middleware services that decouple systems, improve reliability and simplify future changes.

Data Synchronisation

Real-time and scheduled sync processes with validation, error handling and reconciliation built in — eliminating manual fixes and spreadsheet workarounds.

Legacy Integration

Bridging older systems like Visual FoxPro or bespoke databases into modern .NET and SQL Server ecosystems without disrupting operations.

Business Process Alignment

Integrations designed around how your business actually works — not just technical connectivity, but real operational flow.

Resilient Architecture

Fault-tolerant integrations with logging, retry logic and monitoring to ensure systems stay in sync even under failure conditions.

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Core Delivery Areas

Senior-level delivery across legacy modernisation, backend application engineering, SQL Server optimisation and complex systems integration.

Legacy system modernisation .NET migration

Legacy Modernisation

Move Visual FoxPro and older business platforms into maintainable .NET and SQL Server solutions while preserving critical business rules.

Backend & SQL Systems

Design resilient backend services, optimise stored procedures and support data-heavy operational platforms.

Integration & APIs

Connect Sage 200, ERP, ecommerce and third-party platforms through robust API and synchronisation layers.

Key Achievements

Proven delivery across high-scale, business-critical systems.

1M+ Transactions Annually

Designed and delivered systems handling high-volume transactional workloads in production environments.

50,000+ Users Supported

Built and maintained platforms supporting large consultant networks and distributed teams.

Multi-Country Deployments

Delivered enterprise systems deployed across multiple regions including Africa and the UK.

Backend Application Development

Design and development of robust, scalable business applications powered by .NET backends and SQL Server.

custom .NET business application development

Custom Business Applications

Build secure, scalable backend-driven systems tailored to complex operational requirements.

Workflow & Data Systems

Develop backend services and data platforms to manage workflows, reporting, and integrations.

Example: Teleios Warranty System

Custom-built .NET backend platform managing warranties, policies, and operational data processes.

Selected Project Experience

Examples of real-world systems, integrations and modernisation work delivered in production environments.

Legacy VFP to .NET Platform

Rebuilt a complex Visual FoxPro business system into a modern .NET and SQL Server platform, preserving critical business logic while improving scalability and maintainability.

High-Volume SQL Processing System

Optimised and redesigned SQL Server procedures supporting over 1 million transactions annually, significantly improving performance and reporting accuracy.

Sage 200 Integration Layer

Designed and implemented integration between Sage 200, ecommerce systems and internal applications, replacing manual processes with automated data synchronisation.

Custom Warranty Platform

Built a full .NET backend system for warranty and policy management, including workflows, reporting and operational data handling.

Multi-System Integration Architecture

Developed middleware services to connect multiple business systems, ensuring reliable data flow with validation, logging and retry mechanisms.

Compensation & Reporting Engine

Designed complex SQL-driven calculation engines for multi-level compensation structures with high data volumes and intricate business rules.

About

Solutions architect and developer with decades of experience delivering business-critical systems, modernising legacy platforms, and leading complex integration projects.

I am a versatile and self-motivated professional with extensive experience across the software lifecycle—from system design and architecture to hands-on development and delivery. My work spans ERP, ecommerce, mobile applications and high-volume transactional systems.

I specialise in modernising legacy environments, including Visual FoxPro, into scalable .NET and SQL Server platforms while preserving complex business rules and operational continuity. I also design and build bespoke backend-led applications from scratch for organisations with demanding process, reporting and integration needs.

My focus is on serious business systems rather than brochure websites or CMS work—typically projects involving data, workflow, integration and long-term maintainability.

Contact

Discuss backend systems, integration work, legacy modernisation or new application builds.

Get in touch

Direct contact

Email: rodney@rhesys.co.uk

Location: Near Edinburgh, Scotland

Availability: Remote-first, contract and specialist project work

Focus: .NET backend systems, SQL Server, Sage 200 integration, APIs and legacy modernisation