Contract Software Developer

iO Associates - UK/EU; Milton Keynes; On-site; GBP 92,250 - 110,700; Full time

Job summary

A leading consulting firm in Milton Keynes is seeking a Lead Principal Consultant for a contract role in Government, Defence & Security. The ideal candidate will have expertise in C# .NET Core or C++, along with experience in AWS, Docker, and security practices. The position offers a competitive day rate of £500 to £600, with the requirement of active UK*C DV clearance. This role is well-suited for mid-senior level professionals.

Qualifications

• Experience with cloud platforms (AWS, Azure, GCP) and containerization (Docker, Kubernetes).
• Exposure to security tools (SAST, DAST, dependency scanning).
• Knowledge of compliance frameworks (ISO 27001, NIST).

Responsibilities

• Design, develop, and maintain software using C# .NET Core or C++.
• Build APIs and microservices aligned with business and technical requirements.
• Embed secure coding practices into all development activities.

Skills

C# .NET Core

C++

Docker

Kubernetes

AWS

Azure

GCP

SAST

DAST

Education

Certifications in software development, cloud, or security

Tools

CI/CD

Job description

Overview

Title: Lead Principal Consultant - Government, Defence & Security

Role: Contract Software Developer

Clearance: UK*C DV

Day rate: £500 to £600 | Outside IR35 | DOE

Responsibilities

• Design, develop, and maintain software using C# .NET Core (v6+) or C++ (C++11+), with opportunities to work on .NET Core 8 microservices.


• Build APIs and microservices aligned with business and technical requirements.


• Embed secure coding practices into all development activities and CI/CD pipelines.


• Participate in code reviews, architecture discussions, and team retrospectives to drive quality and maintainability.


• Write unit and integration tests to ensure reliable, production-ready software.


• Stay up-to-date with modern development practices, frameworks, and security trends.

Qualifications

• Experience with cloud platforms (AWS, Azure, GCP) and containerization (Docker, Kubernetes).


• Exposure to security tools (SAST, DAST, dependency scanning).


• Knowledge of compliance frameworks (ISO 27001, NIST).


• Certifications in software development, cloud, or security.

Please note: this role requires active UK*C DV Clearance.

If this sounds of interest, or you hold the right clearance but are looking for a slightly different role, please reach out for a confidential conversation to find out more!

Additional details

• Seniority level: Mid-Senior level


• Employment type: Contract


• Job function: Information Technology and Strategy/Planning


• Industries: IT System Custom Software Development, Software Development, and IT Services and IT Consulting