Senior Software Engineer

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 rolewill 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