CESM Software Engineer II

ucar; Boulder (CO); On-site; USD 83,000 - 104,000; Full time

Job summary

UCAR in Boulder, CO, seeks a Software Engineer to modernize the CESM modeling ecosystem toward new architectures and computational approaches. The role requires profiling, refactoring legacy code, and collaborating across scientists and engineers to implement modernization strategies.

As part of the CGD Laboratory's Computer Engineering Group, you will work on performance improvements, memory reductions, and hardware portability, including GPUs, while staying current with emerging tools and

Qualifications

• Bachelor's degree in computer-related field with 4–8 years of experience or equivalent.
• Ability to identify performance bottlenecks through profiling and analysis.
• Ability to modernize software via refactoring and updated libraries/frameworks.
• Experience with software requirements analysis and systems design.
• Able to work independently and in a team on complex projects.
• Strong attention to detail and communication skills.
• Experience with at least one compiled language (Fortran, C, C++).

Responsibilities

• Enhance the CESM modeling ecosystem for performance, memory, and portability.
• Collaborate with team members and stakeholders on integration plans.
• Review existing modeling software for structure, quality, and maintainability.
• Document findings and decisions to support knowledge sharing.
• Explore benchmarks in newer languages and paradigms.
• Stay current with tools and techniques for software modernization.

Skills

Performance profiling

Code analysis

Refactoring legacy code

Software development process

Team collaboration

Attention to detail

Compiled languages (Fortran/C/C++)

Education

Bachelor's degree in computer-related field

Tools

MPI

OpenMP

OpenACC

Job description

Position Type

Regular

Visa Sponsored Job

Yes

Relocation Assistance Eligible

Yes

Hiring Range

83,299.00 USD - 104,127.00 USD *Final salary and rates are based on education, experience, and skills relevant to the role.

Application Closes

12:00am MST on 2026-09-08

About the Role

This position will focus on modernizing the software in CESM, a world-leading Earth system model, towards new architectures, infrastructure and computational approaches. The work will require some knowledge of algorithms, data structures, software development and hardware platforms, as well as attention to detail, and will emphasize problem solving and rapid development for the scientific community we serve. The position will interact with our Community Software Facility, as well as a variety of software engineers and scientific leadership on targeted, strategic priorities.

This Software Engineer position is part of the computer engineering group within NSF NCAR's CGD Laboratory. CGD is home to approximately 130 staff members, along with visiting researchers from around the world. Together, they advance the understanding of Earth system variability and change while addressing the risks of environmental change through collaborative, innovative, and inclusive research. More information about CGD can be found online at https://www.cgd.ucar.edu/.

Job Description

Application Deadline: This position will be posted until 11:59 pm MDT on Monday, September 7, 2026.

Background Checks: Conducted for candidates selected for hire. Learn more .

Work Location: Regardless of flexible work arrangements, UCAR requires ALL positions to be performed within the U.S., excluding U.S. Territories.

Visa Sponsorship and Relocation Assistance may be available to final candidate if eligible.

What You Will Do

• Participates in the enhancement of the CESM modeling ecosystem, targeting performance improvements, memory reductions, hardware portability (GPUs) and other key strategic needs.
• Collaborates with team members & project stakeholders on proposed changes & processes for integration into the model.
• Review and analyze existing modeling software capabilities to assess its structure, quality, and maintainability.
• Document findings, proposed changes, and technical decisions to support knowledge sharing across a wide team of scientists and engineers.
• Explore & evaluate benchmarks in newer languages and paradigms.
• Stay current with emerging tools, languages & techniques relevant to software modernization.

Who We'd Love To Join Our Team

Successful candidates will ensure their application materials speak to the following criteria:

Education and Experience (Required)

Bachelor's degree in computer-related field and progressive relevant experience, which is typically gained by four to eight years of experience; or equivalent combination of education and experience.

Knowledge, Skills, and Abilities

• Proven ability to identify performance bottlenecks, inefficiencies, and other technical limitations through profiling, testing, and code analysis.
• Ability to recommend and implement modernization strategies, including refactoring legacy code, updating outdated libraries or frameworks, and applying current development standards and best practices.
• Demonstrated skill applying the software development process, including participation in software requirements analysis and systems design.
• Ability to work both independently and within a team on interesting & challenging software projects.
• Attention to detail and strong communication skills to accurately assess and convey complexities.
• Experience with at least one compiled language (Fortran, C, C++, etc).

Desired

• Familiarity with parallel programming (MPI, OpenMP, OpenACC, JAX, etc)
• Some knowledge of numerical methods, data structures and algorithms.

Preferred Qualifications

Salary Range $83,299 - $104,127 *Final salary and rates are based on education, experience, skills relevant to the role.