Senior & Principal C# / .NET/AI Developer | Application Modernization & AI (Oil & Gas Industry)

High Country Search Group; Denver (CO); On-site; USD 150,000 - 235,000; Full time

Benefits offered by this job

Health coverage

401(k) match

5–7 weeks vacation

Parental leave

Free daily lunch

Parking/transit

Wellness benefits

Student loan assistance

Job summary

High Country Search Group is seeking Senior & Principal C# / .NET/AI Developers for an Application Modernization & AI initiative in the Oil & Gas sector. You will help modernize legacy applications and drive AI-enabled development.

The roles require 10+ years in C#, .NET, and SQL Server, plus hands-on AI tooling experience. Denver-area residents who can be onsite 4 days a week are preferred. Competitive base salaries with annual bonuses and stock grants are offered.

Qualifications

• 10+ years of engineering experience, with heavy focus on C#, .NET, and Microsoft SQL Server.
• Hands-on experience with AI-assisted coding tools (Claude Code, GitHub Copilot, OpenAI Codex) and AI-forward transformation.
• Experience with Microsoft Azure, Infrastructure as Code, Git, and CI/CD pipelines; strong automated testing (unit/integration/e2e).
• Bachelor’s degree in Computer Science, Engineering, or related field.
• Experience in oil & gas, energy, or asset-intensive industries.

Job description

HIRING: Senior & Principal C# / .NET/AI Developer | Application Modernization & AI (Oil & Gas Industry)

A LITTLE ABOUT THE COMPANY

My client is a leading independent energy company focused on natural gas, NGLs, and oil production, one of the biggest in Colorado. They also have property in West Virginia and Pennsylvania and more than 15 years of Tier 1 drilling inventory. With over $5 Billion in revenue and executive leadership based in Denver, the company is investing heavily in a Board- and C-suite-backed digital transformation, building an internal software engineering team to modernize legacy applications and drive AI-enabled development across the organization.

ROLE REQUIREMENTS

• 10+ years of engineering experience, heavy in C#, .NET, and Microsoft SQL Server
• Deep, Hands-on experience with AI-assisted/agentic coding tools such as Claude Code, GitHub Copilot, or OpenAI Codex (and a passion for AI-forward transformation)
• Experience with Microsoft Azure, Infrastructure as Code, Git, and CI/CD pipelines.
• Strong automated testing experience, including unit, integration, and end-to-end testing.
• Deep, Hands-on experience with AI-assisted/agentic coding tools such as Claude Code, GitHub Copilot, or OpenAI Codex (and a passion for AI-forward transformation)
• Bachelor's degree in Computer Science, Engineering, or a related field
• Experience in oil & gas, energy, or asset-intensive industries

NICE TO HAVE:

• Experience with PostgreSQL
• Experience with AI/LLM applications
• Experience with RAG and vector databases
• Familiarity with Azure Foundry, Python
• Experience with Power BI and Azure Data Factory
• Familiarity with Power Platform and SharePoint

LOCATION

*This person must currently reside in the Denver area AND be open to spending 4 days onsite at our client's Denver office.

COMPENSATION:

The Principal role offers a $180K–$235K base salary.

The Senior role offers a $150K–$180K base salary.

Both also offer a 15%–20% annual bonus and 10%–25% stock grants. Benefits include 100% company-paid health coverage, 7% 401(k) match, 5–7 weeks of vacation, paid parental leave, free daily lunch, parking/transit, wellness benefits, and student loan assistance.

NOTE: This client is unable to offer sponsorship or visa transfers at this time.