.NET Developer (Contract)

Ocho People; Toome; On-site; GBP 80,000 - 100,000; Full time

Job summary

A Mid Ulster manufacturing company is looking for an experienced contractor to help rewrite a legacy platform using modern .NET technologies. The role involves designing, building, and shipping production-ready services while mentoring the in-house team. Strong experience in C#/ASP.NET Core and migration from legacy systems is essential. This on-site role offers an immediate start and a day-rate contract.

Qualifications

• Proven experience in migrating legacy .NET Framework applications to modern .NET.
• Strong knowledge of designing and building secure APIs.
• Experience with CI/CD pipelines and deployment automation.

Responsibilities

• Lead the rewrite from .NET Framework to modern .NET.
• Design and implement CI/CD pipelines for deployment.
• Mentor the in-house engineering team.

Skills

C#/.NET Core/.NET 6-8

ASP.NET Core Web API

Entity Framework Core

SQL Server

Performance tuning

Secure coding practices

CI/CD with Azure DevOps

Logging/metrics/tracing

Tools

Azure DevOps

GitHub Actions

Docker

Kubernetes

Job description

Location

Mid Ulster (on-site 4 days/week during onboarding, moving to 3 days/week thereafter)

Contract

Day-rate contract, rate negotiable, immediate start available, IR35 status to be confirmed via SDS

About the role

Our client, a Mid Ulster manufacturing business, is rewriting a legacy platform onto modern .NET. They need an experienced contractor to add both expertise and capacity, helping design, build, and ship production-ready services while transferring knowledge to the in-house team.

What you\'ll do

• Lead and contribute to the rewrite from .NET Framework to modern .NET (e.g. .NET 8)
• Build secure, performant APIs and services with ASP.NET Core and Entity Framework Core
• Refactor legacy components, reduce tech debt, and improve reliability and observability
• Design data access patterns for SQL Server; tune queries, indexing, and migrations
• Implement CI/CD pipelines (Azure DevOps/GitHub Actions) and deployment automation
• Introduce testing discipline (unit/integration), code reviews, and coding standards
• Collaborate with manufacturing stakeholders to align solutions with shop-floor workflows
• Document architecture, decisions, and run-books; mentor permanent engineers

Essential experience

• Strong commercial C#/.NET Core/.NET 6-8 and ASP.NET Core Web API
• Deep experience migrating legacy .NET Framework applications to modern .NET
• Entity Framework Core, SQL Server, performance tuning and profiling
• Secure coding practices, authentication/authorisation, configuration management
• CI/CD with Azure DevOps or GitHub Actions; IaC and deployment automation
• Logging/metrics/tracing with tools such as Serilog, Application Insights, OpenTelemetry
• Working in hybrid on-site teams; clear stakeholder communication

Desirable

• Message queues (Service Bus/RabbitMQ), caching, and distributed systems patterns
• Front-end awareness (Blazor/React) for cross-stack collaboration
• Docker/Kubernetes, Windows and Linux hosting, reverse proxies, networking basics
• Manufacturing domain exposure (ERP/MES integrations, barcode/label workflows, PLC/OPC UA)
• Experience introducing coding standards and lightweight governance in SME environments

Why this contract

• Direct impact: define the target architecture and delivery pace for a full platform modernisation
• Knowledge transfer: shape standards and upskill an engaged in-house team
• Momentum: immediate start, clear deliverables, and visible outcomes on the shop floor

How to apply

Apply here or reach out to Aaron Somers at Ocho for more information via LinkedIn.