Senior Software Developer C#

Date: Oct 6, 2026 Location: Oslo, 03, NO, 0167

Job Duties
Landmark, a Halliburton company, builds the software and data platforms that help the global energy industry make better decisions. Our products span subsurface interpretation, well construction planning, reservoir simulation, and digital operations — tools used daily by engineers and scientists at the world’s largest energy companies. We are investing significantly in our engineering capability in Oslo, and these roles are part of building a permanent, locally-owned engineering organization to take long-term ownership of the platform.

We are hiring experienced C# developers to build and evolve the .NET services at the core of the platform. These are backend roles on services that handle demanding, domain-rich workloads in the energy space — services that need both ongoing feature development and the careful maintenance that keeps a production platform reliable. Parts of the codebase are written in F#, so comfort with — or a willingness to pick up — a functional style alongside C# is a welcome plus. You will work in a modern microservices environment with REST and message-based communication, in a team that takes engineering quality seriously and treats AI-assisted development as a normal, everyday way of working. You will collaborate closely with other backend and full-stack engineers, and your work will sit directly behind tools that engineers and scientists at major operators rely on.

Backend Service Development

• Design, build, and maintain .NET backend services in C#, using ASP.NET Core and an ORM such as Entity Framework, to deliver and evolve platform capabilities.
• Work across parts of the codebase written in F#, contributing to or extending functional code where the platform uses it.
• Own features end to end — from design through implementation, testing, and production support — with a high degree of personal ownership.

Architecture and Integration

• Build within a microservices architecture, designing clean REST APIs and message-based integrations between services.
• Make pragmatic design decisions about service boundaries, data access, and inter-service communication, and contribute to the platform’s evolving technical standards.
• Integrate with the platform’s data stores and streaming infrastructure, working alongside the data and DevOps teams as needed.

Quality and AI-Assisted Engineering

• Hold a high bar for code quality — automated testing, code review, and maintainable design — so the platform stays fast and safe to change.
• Use AI-assisted coding tools (Claude Code, Copilot, and similar) as a normal part of your daily workflow to work faster without lowering the quality bar.
• Contribute to a strong, collaborative engineering culture: sharing knowledge, reviewing peers’ work constructively, and helping raise the team’s overall standard

Qualifications & Experience

• Master’s degree in Computer Science, Software Engineering, or a closely related STEM discipline.
• Strong C# with solid production experience building backend services.
• .NET backend development experience, including ASP.NET Core and Entity Framework or a similar ORM.
• Comfortable with microservices architecture, REST API design, and message-based communication between services.
• Proficient with AI-assisted coding tools (Claude Code, Copilot, or similar) in daily work.

Preferred

• F# experience, or a genuine willingness to learn and work in F# (parts of the codebase use it).
• Experience with PostgreSQL, Kafka, Kubernetes, and Azure.
• Exposure to the oil & gas or wider energy domain.
• Experience working in a monorepo with code review, and with continuous integration and incremental delivery.
• We welcome candidates from all backgrounds and encourage you to apply even if your experience does not match every item in the preferred list.

Why Landark
These roles are part of a deliberate investment in building a permanent engineering organization in Oslo, with real ownership of a platform used across the global energy industry. We build small, high-ownership teams and invest in the quality of every person on them. Engineers here co-author the product strategy alongside product management and domain science: the art of the possible is an engineering contribution, not a function that sits upstream. You will work in a business where software is the product, solving technically demanding problems in a domain where your improvements have visible, measurable impact. We offer competitive compensation including bonus and long-term incentive programs, and the scope to build something that lasts.

Minimum Qualifications: Minimum qualifications may be acquired through technical schools or equivalent related experience. Candidates having qualifications that exceed the minimum job requirements will receive consideration for higher level roles given (1) their experience, (2) additional job requirements, and/or (3) business needs. Depending on education, experience, and skill level, a variety of job opportunities might be available from the Senior Software Principal - Advisor

Halliburton is an Equal Opportunity Employer. Employment decisions are made without regard to race, color, religion, disability, genetic information, pregnancy, citizenship, marital status, sex/gender, sexual preference/ orientation, gender identity, age, veteran status, national origin, or any other status protected by law or regulation .

Location
Wergelandsveen 1, Oslo, , 0167, Norway

Job Details

Requisition Number: 209485
Experience Level: Experienced Hire
Job Family: Engineering/Science/Technology
Product Service Line: Landmark Software & Services
Full Time / Part Time: Full Time

Additional Locations for this position:

Compensation Information
Compensation is competitive and commensurate with experience.

Job Segment: Developer, Testing, .NET, C#, Computer Science, Technology