Senior Software Engineer
CoStar Group
About the role
Senior Software Engineer
Job Description
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.
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#CoStar
CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing
Responsibilities
- Design, build, and maintain production applications using C# and .NET
- Use 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 promote engineering best practices
Qualifications
- Bachelor's degree from an accredited, not-for-profit, in-person college or university
- Strong experience with C# and .NET or .NET Core
- Hands-on AWS experience, including EC2, ECS/EKS, Lambda, S3, RDS, DynamoDB, or CloudWatch
- Experience building APIs and backend services
- Solid understanding of software design principles
- Experience with Git-based workflows
- Track record of commitment to prior employers
- Preferred: practical Claude coding or code review experience, Databricks, microservices or distributed systems, CI/CD, DevOps, Infrastructure-as-Code, or additional AI coding tools
Benefits
- Medical, vision, dental, and prescription coverage
- Life, legal, and supplementary insurance
- Mental health counseling services
- Commuter and parking benefits
- 401(k) with matching contributions
- Employee stock purchase plan
- Paid time off
- Tuition reimbursement and internal training
- Fitness facilities or membership reimbursement, with wellness classes and services
- Employee Resource Groups
- Complimentary coffee, tea, fruit, and healthy snacks
Skills mentioned
About CoStar Group
CoStar Group (NASDAQ: CSGP) is a global leader in commercial real estate information, analytics, online marketplaces, and 3D digital twin technology. Founded in 1986, CoStar Group is dedicated to digitizing the world’s real estate, empowering all people to discover properties, insights, and connections that improve their businesses and lives. CoStar Group’s major brands include CoStar, a leading global provider of commercial real estate data, analytics, and news; LoopNet, the most trafficked commercial real estate marketplace; Apartments.com, the leading platform for apartment rentals; Homes.com, the fastest-growing residential real estate marketplace; and Domain, one of Australia’s leading property marketplaces. CoStar Group’s industry-leading brands also include Matterport, a leading spatial data company whose platform turns buildings into data to make every space more valuable and accessible; STR, a global leader in hospitality data and benchmarking; Zonda, a leading provider of data, analytics, software, and marketplace solutions for the residential construction industry; Ten-X, an online platform for commercial real estate auctions and negotiated bids; and OnTheMarket, a leading residential property portal in the United Kingdom. CoStar Group’s websites attracted over 118 million average monthly unique visitors in the second quarter of 2026, serving clients around the world. Headquartered in Arlington, Virginia, CoStar Group is committed to transforming the real estate industry through innovative technology and comprehensive market intelligence. From time to time, we plan to utilize our corporate website as a channel of distribution for material company information. For more information, visit CoStarGroup.com.