Senior .NET Engineer — Cloud, AI, AWS (Hybrid)

CoStar Group; San Diego (CA); Hybrid; USD 124,000 - 187,000; Full time

Benefits offered by this job

Healthcare coverage

401(K) matching

Employee stock purchase plan

Tuition reimbursement

Job summary

CoStar Group is seeking a Senior Software Engineer in San Diego, CA, specializing in C#/.NET with AWS cloud-native experience. You will work heavily with Claude for AI-assisted development and contribute to scalable backend services. This hybrid role offers 4 days onsite and 1 day remote.

You will design and implement production-grade software, participate in code reviews, and mentor engineers while advancing performance and reliability across cloud-based solutions.

Qualifications

• Bachelor's degree from an accredited, in-person college/university.
• Proven experience with C# and .NET/.NET Core.
• Hands-on AWS experience (EC2, ECS/EKS, Lambda, S3, RDS, DynamoDB, CloudWatch).
• Experience building APIs and backend services.
• Experience with Git-based workflows.

Responsibilities

• Design, build, and maintain production applications using C# and .NET.
• Leverage Claude for code generation, refactoring, debugging, and analysis.
• Build and operate cloud-based solutions on AWS.
• Collaborate with product, architecture, and engineering teams.
• Participate in system design, code reviews, and technical decision-making.
• Improve application performance, scalability, and reliability.
• Mentor engineers and contribute to engineering best practices.

Skills

C#

.NET

Claude AI

AWS

APIs/Backend

Git workflows

Microservices

CI/CD

Education

Bachelor's degree

Tools

AWS EC2

AWS ECS/EKS

AWS Lambda

AWS S3

AWS RDS

AWS DynamoDB

CloudWatch

Databricks

Terraform

CloudFormation

CDK

Job description

CoStar Group is seeking a Senior Software Engineer in San Diego, CA, specializing in C#/.NET with AWS cloud-native experience. You will work heavily with Claude for AI-assisted development and contribute to scalable backend services. This hybrid role offers 4 days onsite and 1 day remote.

You will design and implement production-grade software, participate in code reviews, and mentor engineers while advancing performance and reliability across cloud-based solutions.