Senior Software Engineer; C#​/.NET

Senior Software Engineer (C#/.NET) Job Description

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 and the NASDAQ 100, 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.

The Product Data Services team is seeking a Senior Software Engineer to join us in building backend services powering CoStar’s products. Come be an integral part of brands across the organization such as , , CoStar and more to solve problems of scale, consistency, and performance. Working primarily on Amazon Web Services components you can have a tangible impact on thousands of end users that use our products.

This position is located in San Diego, CA, and offers a work schedule of 4 days onsite, 1 day work from home.

• Build big, distributed, API‑driven systems for tens of thousands of users
• Produce bullet‑proof code that is robust, efficient, and maintainable; our primary tools are C#, .NET Framework, JSON, SQL Server, and AWS
• Drive and lead software design, development standards, and code reviews
• Continually evaluate emerging technologies to identify opportunities, trends, and best practices that can be leveraged to strengthen CoStar’s technology platform and develop practices

• Bachelor’s degree required from an accredited, not-for-profit, in‑person college/university
• A track record of commitment to prior employers.
• A demonstrable track record of building and launching successful products and/or platforms that leverage terabytes of data and scale to meet the needs of millions of users
• 5 years of deep .NET development (C#) development experience including cross‑platform communication technologies such as Web API
• 2 years of database design, T‑SQL programming, and performance tuning experience
• Ability to design and develop using Object Oriented design principles and software design patterns to attain high reusability and maintainability
• Deliver work products that meet specifications and are defect free and performant
• Experienced in application performance testing and unit testing strategies and implementation
• Excellent software development and engineering skills on large‑scale, mission‑critical infrastructure applications
• Solid understanding of HTTP concepts (status codes, headers, etc.)

• Facilitate discussions among other developers to exchange ideas and introduce new technologies. Ability to build consensus among other technologists
• Experience with .NET Core
• Willingness to take an active role in mentoring other developers
• Demonstrates knowledge of NPM and Nu Get
• AWS or Azure experience
• Experience with AI or Dev Tools

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(…