RJJ Software

Who We Are

RJJ Software Ltd is a technology consultancy based in Leeds, working with small and medium enterprises, high-growth startups, and investors across the UK and beyond. Founded in 2018 (Companies House 11599743), the company pairs strategic advice with hands-on engineering experience, so recommendations are grounded in how software actually gets built.

Much of the writing published under this byline is in the company’s voice: announcements, award news, and work that reflects the wider team rather than a single author.

What We Do

The work spans fractional CTO engagements, technical due diligence, architecture and security reviews, and helping teams adopt AI-assisted and agentic development on their own codebases — safely, and with measurable results. RJJ Software works across .NET, Ruby on Rails, and Python, and emphasises knowledge transfer over consulting dependency.

Recognition

RJJ Software has been named Best Strategic SME Tech Consultancy 2025, recognised as a top five software development company in Leeds by DesignRush, and awarded an Education Award by the West and North Yorkshire Chamber of Commerce for its work developing the next generation of engineers.

Beyond Client Work

RJJ Software produces The Modern .NET Show, one of the longest-running podcasts about modern .NET development, and maintains OwaspHeaders.Core, an open-source security-headers library for ASP.NET Core with over 1.9 million downloads.