Lead Software Engineer

Company 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 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.

Our team is seeking an accomplished Lead Software Engineer to support multiple software products and brands across the organization, such as  You will directly impact highly visible web applications that reach more than 10,000,000 users, continuously learning emerging technologies and architecture advancements to improve our products.

Location:

Irvine, CA. 4 days 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.
• Write unit‑testable software with C#.
• Develop an in‑depth understanding of CoStar’s product architecture and frameworks, maintaining and contributing to the 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 .NET and database developers to exchange new ideas and improvements.
• Continuously evaluate emerging technologies to identify opportunities, trends, and best practices that strengthen CoStar’s technology platform and development practices.

• Bachelor’s Degree from an accredited institution.
• Track record of commitment to prior employers.
• Working knowledge of Vue, React, or Angular in Type Script.
• Experience with AWS S3, SQS, Dynamo, Elasti Cache, Apache Kafka, and Datadog.
• Experience using AI coding tools for development, refactoring, and debugging (Claude Code, Git Hub Copilot, or equivalent).
• 9+ years of production development experience with C# .Net (or .Net Core).
• Demonstrable track record of building and launching successful products and platforms.
• Ability to deliver products that meet specifications and performance SLAs.
• Deep understanding of 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.
• Mentoring developers and building consensus.
• Experience in unit, performance, and automation testing.

• Comprehensive health care coverage: medical, vision, dental, prescription drug.
• Life, legal, and supplementary insurance.
• Virtual and in‑person mental health counseling services.
• 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 employee resource groups.
• Complimentary coffee, tea, hot chocolate, fresh fruit, and 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, 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.