Backend development
C#, .NET, APIs, integrations, business logic, maintenance, and modernization of existing systems.
John Nielsen
Senior Backend & Infrastructure Consultant
I help companies stabilize, modernize, and operate business-critical software systems.
I am a senior backend and infrastructure engineer with around 25 years of experience across .NET, SQL Server, CI/CD, deployment automation, hosting, and production operations. I work best where reliability, operational clarity, and pragmatic engineering matter more than buzzwords.
My background includes long-term responsibility for production systems where downtime, deployment mistakes, and operational ambiguity had real business consequences.
Services
What I do
I help companies with systems that need to keep running, keep evolving, and remain understandable to the people responsible for them.
Infrastructure and operations
Production systems, hosting, Linux/Windows servers, IIS, SQL Server, deployment environments, monitoring, and operational troubleshooting.
CI/CD and deployment automation
Build pipelines, TeamCity, deployment workflows, release processes, automation, and reducing manual operational risk.
Legacy system modernization
Incremental modernization of older systems without reckless rewrites or unnecessary architectural theatre.
SQL Server and data-heavy systems
Practical experience with large SQL Server installations, performance-aware development, and production data concerns.
Technical rescue and stabilization
Helping teams understand fragile systems, remove operational bottlenecks, and make production behavior more predictable.
Approach
How I work
I prefer simple, robust solutions over unnecessary complexity. My background is strongly shaped by long-term responsibility for production systems: keeping services alive, debugging real failures, handling deployments, reducing operational risk, and making systems easier to reason about.
I can work independently, integrate into existing teams, or help as a senior external consultant when a project needs senior technical ownership.
- Direct communication
- Low-drama execution
- Strong production focus
- Pragmatic architecture
- Comfortable with legacy systems
- Comfortable with modern tooling
- Remote-first, Denmark-facing
- Available for contract or consulting work
Track record
Experience highlights
- Around 25 years of professional software and infrastructure experience
- Long-term work with C#, .NET, SQL Server, IIS, and backend systems
- Extensive experience with TeamCity-based CI/CD and deployment processes
- Production responsibility for large business-critical systems
- Experience with server operations, hosting, monitoring, and incident response
- Experience modernizing legacy systems incrementally
- Background in e-commerce / SaaS-style production environments
- Comfortable bridging development and operations
Fit
Who I help
I am a good fit for companies that have important existing systems and need senior help to maintain, stabilize, modernize, or extend them.
- Companies with mature .NET systems
- Teams with fragile deployment processes
- Businesses with important legacy systems
- Organizations that need production-aware engineering
- Teams that need senior backend/infrastructure capacity
- Companies preparing for scale, peak load, or operational cleanup
Availability
Engagement types
Available for consulting and contract-based work.
- Short technical assessments
- Part-time advisory work
- Full-time contract assignments
- Backend/infrastructure implementation work
- CI/CD and deployment improvement projects
- Legacy modernization projects
- Production troubleshooting and stabilization
Currently open to discussing Danish / Northern European consulting and contract opportunities.
Contact
Contact
The easiest way to reach me is by email.
Send me a short message with the problem, system context, expected time frame, and whether the work is remote, hybrid, or on-site.