CoStar Group

Build scalable backend systems, leverage AI tools, make architecture decisions, and mentor engineers. | Bachelor's degree and 6+ years experience in C#/.NET backend development with strong API and testing skills. | Senior Software Engineer - LoopNet 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. LoopNet, the most popular place to find a space, is the #1 global commercial real estate marketplace. With more than 12 million global unique monthly visitors, LoopNet provides brokers, buyers and sellers with what they need to meet and make deals. LoopNet has established itself as the most effective and far-reaching digital marketplace for commercial real estate owners and brokers. We are not done yet! We continue to focus on driving expansion by increasing market share in the US and abroad, continuously innovating and enhancing the product and growing a powerhouse global team to reach our goals. Learn more about LoopNet. We are seeking a highly skilled Senior Software Engineer with deep expertise in C#/.NET, AWS cloud development, and hands-on experience with AI coding tools such as Claude Code or GitHub Copilot. In this role, you will contribute to building scalable, high-quality systems across multiple products and brands—including LoopNet.com—while leveraging modern AI-driven development practices to accelerate delivery and improve code quality. You will also play a key role in architecture decisions and mentoring engineers across the team. This position is located in Irvine, CA and offers 4 days a week onsite with 1 day work from home. BASIC QUALIFICATIONS: Bachelor’s degree from an accredited, not-for-profit university or college. A demonstrated track record of commitment with prior employers. 6+ years of production development experience with C# and .NET or .NET Core. Proven history of building and launching successful products and platforms. Experience delivering products that meet specifications and performance SLAs. Solid experience writing unit, performance, and automated end-to-end tests Strong experience building APIs and backend systems with a solid grasp of software design principles. Deep understanding of the business context for which you are building software. Active participation in mentoring developers and building team consensus. PREFERRED QUALIFICATIONS: Working knowledge of Vue.js or React in TypeScript. Experience with relational database design (MS SQL or MySQL), including performance tuning. Hands-on experience with AWS services including S3, SQS, DynamoDB, and ElastiCache, as well as Apache Kafka and Datadog. Experience with microservices, distributed systems, Docker, and Kubernetes. Familiarity with CI/CD pipelines, DevOps practices, and Infrastructure as Code tools. Application security knowledge and experience with Git-based workflows. Hands-on professional experience with AI coding tools such as Claude Code, GitHub Copilot, or equivalent. Experience with cloud data warehouse platforms (BigQuery, Databricks, or Snowflake) and proficiency in Python for data engineering or analytics workflows. 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 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: $124,000-$187,000 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. #LoopNet #LI-PM3 CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing

Provide technical leadership and architectural direction while managing engineering teams and driving project execution. | Bachelor's degree, 7+ years software engineering experience, 2+ years leadership, proficiency in full-stack cloud-native development. | Manager, Software Engineering 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. As a Technical Manager in Software Engineering, you will be responsible for providing project definition and implementation through hands-on management of software development teams leveraging Agile Scrum development and project management best practices defined by the company. You will undertake the execution of software development projects to achieve the company’s strategic objectives and must work closely with Product Leaders & other managers. 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 offers a schedule of Monday to Thursday in office and the option to work from home on Friday. Responsibilities Provide technical leadership, architectural direction, and delivery ownership for a portfolio of software products and platforms. Lead and mentor high-performing teams of software engineers building scalable applications and services using TypeScript, React, Node.js, .NET, SQL Server, AWS, and AI technologies. Serve as a player-coach by guiding technical design, reviewing code, removing delivery obstacles, and contributing to key engineering initiatives. Drive execution across multiple projects, coordinating priorities, dependencies, and resources within engineering and across business functions. Champion AI-assisted software development practices that improve developer productivity, code quality, platform reliability, and engineering efficiency. Leverage AI-powered observability, monitoring, anomaly detection, replayability, and automation capabilities to improve system resiliency, incident response, and customer experience. Partner with Product, Engineering, and business stakeholders to identify and implement intelligent solutions that streamline workflows, reduce manual effort, and accelerate business outcomes. Lead the design, development, and governance of AI-powered solutions, including agents, tools, skills, copilots, and workflow automations that enhance internal operations and customer-facing products. Establish and enforce engineering best practices related to software quality, security, scalability, observability, and operational excellence. Promote responsible AI adoption by ensuring solutions meet established security, privacy, compliance, governance, and quality standards. Apply modern quality management practices to deliver reliable, maintainable, and defect-resistant software solutions. Represent the voice of the customer during product planning, design reviews, and release readiness processes to ensure solutions meet customer expectations. Basic Qualifications Bachelor’s degree in Computer Science, Software Engineering, Information Systems, or a related technical field from an accredited, not for profit, in-person university or college. Track record of commitment to prior employers. 7+ years of professional software engineering experience, including full-stack application development. 2+ years of engineering leadership experience managing software development teams. Proven experience delivering and scaling successful software products throughout the software development lifecycle. Hands-on experience with TypeScript, C#, .NET, React, SQL Server, Elasticsearch, AWS, and modern cloud-native development practices. Strong understanding of software architecture, distributed systems, API design, and scalable application development. Experience evaluating, adopting, or developing AI-powered solutions and applications. Familiarity with large language models (LLMs), agent frameworks, AI orchestration tools, and AI-assisted development platforms. Understanding of observability, monitoring, telemetry analysis, replayability, automated incident detection, and operational intelligence platforms. Strong written and verbal communication skills with the ability to effectively engage engineers, business stakeholders, and senior leadership. Demonstrated ability to recruit, mentor, develop, and inspire high-performing engineering teams. Preferred Qualifications Experience leading engineering teams through the full software development lifecycle, from strategy and architecture through deployment and ongoing operations. Experience building modern web applications using React and related JavaScript/TypeScript frameworks. Experience developing, deploying, or managing AI-powered applications, copilots, agents, intelligent search experiences, or workflow automation platforms. Experience leveraging AI technologies to improve engineering productivity, software quality, operational monitoring, research workflows, or data stewardship initiatives. Experience implementing AI-enabled data quality solutions, including enrichment, deduplication, classification, entity resolution, anomaly detection, and governance. Experience operating large-scale cloud-native applications in AWS environments. Experience with modern observability platforms and site reliability engineering (SRE) practices. Experience leading teams in highly agile, fast-paced, product-driven environments. Advanced degree in Computer Science, Engineering, or a related technical discipline. 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 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: $182,000 - $235,000 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-KW1 CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing

Build and maintain large-scale distributed API-driven systems and web applications integrating AI workflows, lead software design, and collaborate cross-functionally to improve reliability and decision-making. | Bachelor's degree with 3+ years .NET development, 5+ years TypeScript and modern frontend/backend tooling, proficiency in cloud platforms, infrastructure as code, distributed systems, and willingness to apply AI technologies. | Senior Full Stack 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. As a Senior Software Engineer on the Platform Development team, you will play a key role in expanding the data platform that supports all of CoStar Group’s largest brands including CoStar Suite, LoopNet, Homes.com and Apartments.com. You will deeply understand what drives the business for which you are building software. We firmly believe that what separates a good developer from a great one is a deep understanding of the business that they are supporting. 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 Arlington, VA and is in office Monday through Thursday with work from home on Friday. Responsibilities Build big, distributed, API-driven systems for tens of thousands of users. Build and integrate AI skills, agents, tools, and intelligent workflows into internal systems and customer-facing applications across CoStar brands, improving platform intelligence and unlocking new product capabilities. Produce code that is robust, efficient, and maintainable; our primary tools are TypeScript, C#, .NET, SQL Server, AWS. Build and maintain customer-facing and internal web applications using React/TypeScript. Utilize AI models to enhance monitoring, replayability, observability, and diagnostic capabilities to improve system reliability, accelerate problem resolution, and reduce operational risk. Drive and lead software design, development standards, and code review practices. Collaborate with Product, Research, and Data teams to identify opportunities where AI-driven workflows and automation can create business value and improve decision-making. 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. 3+ years of deep .NET development (C#) development experience such as web APIs, background services, and developing and publishing shared packages. 5+ years of experience with TypeScript and modern frontend and backend JS tooling (e.g. Node, Vite, React, etc.). Experience with Infrastructure as Code (IaC) tools such as Terraform. Working knowledge and experience with cloud-based platforms (AWS or Azure). Experience in architecting, designing, and building large-scale distributed, service-oriented systems and web applications in an agile environment. Familiarity with using large language models (LLMs), context engineering, or agent-based architectures. Experience working with monitoring, telemetry, observability, or automated diagnostics platforms. Strong understanding of data quality principles, data governance concepts, and data-centric application design. Preferred Qualifications and Skills Strong communication skills (to both business and technical partners). Experience with React Router Framework and Effect. SQL and database development knowledge. Experience using observability and APM platforms like Datadog. Familiarity with services such as Kafka, DynamoDB, and SQS. Experience with deploying to Kubernetes, EKS, and ECS. Data modeling experience from conceptual, logical, and physical designs. Experience implementing MCP clients and servers, workflow automation platforms, or intelligent search solutions. Experience applying AI-assisted software development practices to improve engineering productivity and code quality. 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) Access to CoStar Group’s Employee Resource Groups Complimentary gourmet coffee, tea, hot chocolate, fresh fruit, and other healthy snacks 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: $143,000 - $187,000 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-AR CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing

Design and develop reusable software using C# and collaborate within Agile teams to maintain the platform and implement database procedures. | Bachelor's degree with 5+ years production experience in C# .Net, proficiency in modern frontend frameworks, and AWS cloud experience. | Software Engineer II - LoopNet Job Description CoStar Group 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. LoopNet, the most popular place to find a space, is the #1 global commercial real estate marketplace. With more than 12 million global unique monthly visitors, LoopNet provides brokers, buyers and sellers with what they need to meet and make deals. LoopNet has established itself as the most effective and far-reaching digital marketplace for commercial real estate owners and brokers. We are not done yet! We continue to focus on driving expansion by increasing market share in the US and abroad, continuously innovating and enhancing the product and growing a powerhouse global team to reach our goals. Learn more about LoopNet. Our team is seeking an accomplished Senior Software Engineer to join our team in supporting multiple software products and brands across the organization, such as www.LoopNet.com. You will have a direct impact on highly visible web applications that touch more than 10,000,000 users. You continuously learn emerging technologies and architecture advancements and apply the learnings to improve LoopNet’s software products. This position is located in Irvine, CA and offers 4 days a week onsite with 1 day work from home. RESPONSIBILITIES: Design and develop using Object Oriented design principles and software design patterns to attain high reusability and maintainability. Deep knowledge and experience in writing unit testable software with C# Develop an in-depth understanding of CoStar’s product architecture and frameworks. Maintain and contribute to CoStar’s product platform as necessary. Develop database stored procedures and SQL scripts/ETL jobs that meet CoStar database standards to implement product requirements. Participate and drive continuous improvement within CoStar’s Agile/Scrum teams. Build consensus among different teams working on software development projects. Facilitate discussions among other .NET and database developers to exchange new ideas and improvements. Continually evaluate emerging technologies to identify opportunities, trends and best practices that can be used to strengthen CoStar’s technology platform and development practices. REQUIRED QUALIFICATIONS: Bachelor’s Degree required from an accredited, not-for-profit in person university or college. A track record of commitment to prior employers. Working knowledge Vue, React or Angular in TypeScript Experience with AWS S3, SQS, Dynamo, ElastiCache, Apache Kafka and Datadog Leverage AI Coding Tools for development, refactoring, and debugging (Claude Code, GitHub Copilot or equivalent). 5+ years of production development experience with C# .Net (or .Net Core) A demonstrable track record of building and launching successful products and platforms Deliver products that meet specifications and performance SLA Deeply understand what drives the business for which you are building software PREFERRED QUALIFICATIONS: Experience in relational database design (MS SQL or MySQL) including performance tuning Application security knowledge and experience with Git-based workflows. Take an active role in mentoring developers with ability to build consensus Experienced in unit, performance, and automation testing 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 of $119,000-$165,000 based on relevant skills and experience and includes a generous benefits plan. #LoopNet #LI-AV1 CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing

Build scalable backend systems using C#/.NET and AWS, lead architecture decisions, and mentor engineers. | Bachelor's degree with 7+ years in C#/.NET, experience in product launches, automated testing, and API design. | LoopNet - Software Engineer II 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. LoopNet, the most popular place to find a space, is the #1 global commercial real estate marketplace. With more than 12 million global unique monthly visitors, LoopNet provides brokers, buyers and sellers with what they need to meet and make deals. LoopNet has established itself as the most effective and far-reaching digital marketplace for commercial real estate owners and brokers. We are not done yet! We continue to focus on driving expansion by increasing market share in the US and abroad, continuously innovating and enhancing the product and growing a powerhouse global team to reach our goals. Learn more about LoopNet. We are seeking a highly skilled Senior Software Engineer with deep expertise in C#/.NET, AWS cloud development, and hands-on experience with AI coding tools such as Claude Code or GitHub Copilot. In this role, you will contribute to building scalable, high-quality systems across multiple products and brands—including LoopNet.com—while leveraging modern AI-driven development practices to accelerate delivery and improve code quality. You will also play a key role in architecture decisions and mentoring engineers across the team. This position is located in Irvine, CA and offers 4 days a week onsite with 1 day work from home. BASIC QUALIFICATIONS: Bachelor’s degree from an accredited, not-for-profit university or college. A demonstrated track record of commitment with prior employers. 7+ years of production development experience with C# and .NET or .NET Core. Proven history of building and launching successful products and platforms. Experience delivering products that meet specifications and performance SLAs. Solid experience writing unit, performance, and automated end-to-end tests Strong experience building APIs and backend systems with a solid grasp of software design principles. Deep understanding of the business context for which you are building software. Active participation in mentoring developers and building team consensus. PREFERRED QUALIFICATIONS: Working knowledge of Vue.js or React in TypeScript. Experience with relational database design (MS SQL or MySQL), including performance tuning. Hands-on experience with AWS services including S3, SQS, DynamoDB, and ElastiCache, as well as Apache Kafka and Datadog. Experience with microservices, distributed systems, Docker, and Kubernetes. Familiarity with CI/CD pipelines, DevOps practices, and Infrastructure as Code tools. Application security knowledge and experience with Git-based workflows. Hands-on professional experience with AI coding tools such as Claude Code, GitHub Copilot, or equivalent. Experience with cloud data warehouse platforms (BigQuery, Databricks, or Snowflake) and proficiency in Python for data engineering or analytics workflows. 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 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: $118,000-$154,000 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. #LoopNet #LI-PM3 CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing

Design and maintain scalable cloud-native applications with AI-assisted development and mentoring. | Bachelor's degree and strong experience with C#/.NET, AWS, and AI development tools. | 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. #LI-CG1 #CoStar CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing 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 37 years, giving us the perspective to create truly unique and valuable products and services. We’ve continually refined, transformed and perfected our approach to our business, creating a language that has become standard in our industry and for our customers. 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. CoStar Group is committed to creating a diverse environment and is proud to be an equal opportunity workplace and affirmative action employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. CoStar Group is also committed to compliance with all fair employment practices regarding citizenship and immigration status. If you are a qualified individual with a disability or a disabled veteran, you may request a reasonable accommodation if you are unable or limited in your ability to use or access www.costargroup.com/careers as a result of your disability. You can request reasonable accommodations by sending an email to recruitaccommodation@costar.com.