Costar Software Engineer Jobs in California (NOW HIRING)

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.

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 Lead 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.

• 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.

• Bachelor’s Degree required from an accredited, not-for-profit 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).
• 9+ 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.

• 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.

• 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.

This position offers a base salary range of $144,000-$222,000, based on relevant skills and experience and includes a generous benefits plan.

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.

CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing.