Senior Software Engineer

Senior Software Engineer 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, 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. We are seeking a Senior Software Engineer who excels at designing and architecting modern web applications. This engineer would support our Web Enterprise team in building the software tools that power our proprietary CRM platform and support our sales and research teams across Homes.com, Costar.com, Apartments.com, LoopNet.com, and more. CoStar is investing heavily in artificial intelligence to accelerate software delivery, improve platform observability, automate research and business workflows, enhance product experiences through intelligent agents and skills, and improve data quality across enterprise systems. Successful candidates will demonstrate a willingness to learn, adopt, and apply AI technologies responsibly to solve complex business and engineering challenges. This position is located in Richmond, VA and is in office Monday through Thursday with work from home on Friday. Responsibilities

• Develop and maintain engaging, responsive, and high-performance web applications using React, TypeScript, and Tailwind CSS.
• Design and implement AI-powered software solutions that enhance the customer experience, improve platform intelligence, and unlock new product capabilities across CoStar brands.
• Build and integrate AI skills, agents, tools, and intelligent workflows into internal systems and customer-facing applications.
• Build reusable, scalable, and secure UI components and libraries with a focus on maintainability and performance.
• Collaborate with Product, Research, and Data teams to identify opportunities where AI-driven automation can create business value and improve decision-making.
• Contribute to and maintain shared component libraries and front-end architecture.
• Write comprehensive unit and integration tests using tools like Jest, React Testing library.
• Participate actively in code reviews, pair programming, and agile ceremonies.
• Take an active role in mentoring other developers.
• Be a subject matter expert in front-end technology stack.
• Continually evaluate emerging technologies to identify opportunities, trends, and best practices that can be leveraged to strengthen CoStar’s technology platform and development practices.

Basic Qualifications

• Bachelor’s Degree required from an accredited, not for profit, in person, university or college.
• A track record of commitment to prior employers.
• Familiarity with large language models (LLMs), prompt engineering, or agent-based architectures.
• 5+ years of production development experiencing using modern front-end frameworks.
• Strong proficiency in React.js, TypeScript and Tailwind CSS.
• Deep understanding of HTML, CSS, JavaScript, and responsive design.
• Solid understanding of RESTful APIs and familiarity with front-end build tools (e.g., Webpack, Babel).
• Strong grasp of web standards, accessibility, and security best practices.
• Experience working in Agile development environments.
• Experience in unit, performance and automation testing.

Preferred Qualifications

• Experience with any state management libraries like Redux, Context API.
• Experience implementing AI agents, workflow automation platforms, or intelligent search solutions.
• Experience applying AI-assisted software development practices to improve engineering productivity and code quality.
• Hands-on experience with CI/CD pipelines and version control using Git.
• Experience with .NET Core and SQL Server with the ability to integrate front-end components into a scalable, secure, and maintainable backend architecture
• Experience with Relational Database Management Systems (SQL Server) and Document Data Systems (Dynamo, Elastic Search) a plus.
• Comfortable working across the stack with Node.js on the server-side
• Nice to have experience with AWS S3, Lambda, SQS, Kafka, Redis.

The final salary or hourly rate offered for this role will fall within the range set forth below based on a variety of factors, including but not limited to, geographic location, skills, and competencies. Base Compensation: $130,500- 170,000 Annually 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. #LI-CH1 CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing