Senior Software Engineer
At a glance
Senior Software Engineering role at CoStar Group. CA San Diego · full-time · $124,000–$187,000 base.
techroles summary, based on the employer's posting.
What you'll do
- Build and support production applications with C# and .NET, keeping them scalable and reliable
- Use Claude to generate, refactor, debug and analyze code
- Run cloud services on AWS and develop APIs and backend systems
- Shape technical decisions through system design, code reviews and collaboration with product and engineering teams
- Raise engineering standards by mentoring colleagues and improving application performance
What you bring
- You hold a bachelor's degree from an accredited, nonprofit college or university with in-person instruction
- You bring strong C# and .NET experience, plus hands-on AWS work across services such as EC2, Lambda or S3
- You have built APIs and backend services, understand software design, and use Git-based workflows
- You have a record of commitment to previous employers
Who this fits
This suits a senior engineer who can build and operate cloud-based software and contribute to technical decisions and mentoring. The job is based in San Diego, with four days onsite and one day working from home. You must already be authorized to work full-time in the United States; visa sponsorship is unavailable.
From the employer
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Job Description
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Overview:
CoStar Group (NASDAQ: CSGP) is a leading global provider of commercial and residential real estate information, analytics, and online marketplaces. Included in the S&P 500 Index, CoStar Group is on a mission to digitize the world’s real estate, empowering all people to discover properties, insights and connections that improve their businesses and lives.
We have been living and breathing the world of real estate information and online marketplaces for over 35 years, giving us the perspective to create truly unique and valuable offerings to our customers. We’ve continually refined, transformed and perfected our approach to our business, creating a language that has become standard in our industry, for our customers, and even our competitors. We continue that effort today and are always working to improve and drive innovation. This is how we deliver for our customers, our employees, and investors. By equipping the brightest minds with the best resources available, we provide an invaluable edge in real estate.
Role Description:
We’re seeking a Senior Software Engineer with strong C#/.NET experience, hands-on use of Claude for AI-assisted development, and proven experience building and operating systems on AWS. This role focuses on developing scalable, cloud-native solutions while leveraging modern AI tools to accelerate development and improve code quality.
This position is located in San Diego, CA and has the work schedule of 4 days onsite and 1 day work from home.
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
Basic Qualifications:
Bachelor's degree required from an accredited, not-for-profit, in-person college/university
A track record of commitment to prior employers.
Strong 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
Solid understanding of software design principles
Experience with Git-based workflows
Preferred Qualifications:
Practical experience using Claude for coding or code review
Experience with Databricks
Microservices or distributed systems experience
CI/CD pipelines and DevOps practices
Infrastructure-as-Code (Terraform, CloudFormation, CDK)
Experience with additional AI coding tools
What’s in it for you?
When you join CoStar Group, you’ll experience a collaborative and innovative culture working alongside the best and brightest to empower our people and customers to succeed. We offer you generous compensation and performance-based incentives. CoStar Group also invests in your professional and academic growth with internal training, and tuition reimbursement.
Our benefits package includes (but is not limited to):
Comprehensive healthcare coverage: Medical / Vision / Dental / Prescription Drug
Life, legal, and supplementary insurance
Virtual and in person mental health counseling services for individuals and family
Commuter and parking benefits
401(K) retirement plan with matching contributions
Employee stock purchase plan
Paid time off
Tuition reimbursement
On-site fitness center and/or reimbursed fitness center membership costs (location dependent), with yoga studio, Pelotons, personal training, group exercise classes
Access to CoStar Group’s Employee Resource Groups
Complimentary gourmet coffee, tea, hot chocolate, fresh fruit, and other healthy snacks
We welcome all qualified candidates who are currently eligible to work full-time in the United States to apply. However, please note that CoStar Group is not able to provide visa sponsorship for this position.
This position offers a base salary range from $124,000 to $187,000 a year, determined by relevant skills and experience, and a generous benefits plan.
#CoStar
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CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing
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