LoopNet - Senior Software Engineer (C#/.NET)

Costar Group; Orange (CA); Hybrid; USD 124,000 - 187,000; Full time

Benefits offered by this job

Comprehensive healthcare coverage

401(K) retirement plan with matching contributions

Tuition reimbursement

Job summary

CoStar Group is seeking a Senior Software Engineer (C#/.NET) to join their team in Irvine, CA. The role involves designing enterprise applications and improving web products used by millions.

You will need 7+ years of development experience with .NET, as well as skills in AWS and frontend frameworks. The company offers competitive compensation, performance incentives, and a collaborative culture.

Qualifications

• 7+ years of production development experience with .NET or .NET Core.
• Experience developing enterprise products/platforms.
• Knowledge of application security.

Responsibilities

• Design and develop enterprise applications with high reusability and maintainability.
• Write unit testable software with C#.
• Contribute to CoStar's product platform as necessary.

Skills

C#

.NET

AWS cloud technologies

Frontend (Vue, React, Angular, TypeScript)

Git-based workflows

Education

Bachelor's degree from an accredited university

Tools

MS SQL

MySQL

Apache Kafka

Job description

LoopNet - Senior Software Engineer (C#/.NET)

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 for our customers. We continually refine, transform and perfect 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.

Our team is seeking an accomplished Senior Software Engineer to join us in supporting multiple software products and brands across the organization. You will have a direct impact on highly visible web applications that reach 10 million+ users. You will continuously learn emerging technologies and architecture advancements and apply the learnings to improve LoopNet’s software products.

This position is in Irvine, CA and offers 4 days a week on-site with 1 day working from home.

RESPONSIBILITIES

• Design and develop enterprise applications using software design principles/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 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 peer .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 university or college.
• A track record of commitment to prior employers.
• 7+ years of production development experience with .NET or .NET Core.
• Working experience with AWS cloud technologies (file storage, data storage, search, cache), Apache Kafka.
• Frontend working knowledge (Vue, React or Angular, and TypeScript).
• A demonstrable track record of building and launching enterprise products/platforms.
• Deliver products that meet specifications and performance SLA; experience in unit, performance, and integration tests.
• Experience with Git-based workflows.
• Deeply understand enterprise application business logic.

PREFERRED QUALIFICATIONS

• Experience in relational database design (MS SQL or MySQL) including performance optimization and NoSQL design.
• Application security knowledge.
• Leverage AI Coding Tools for development, refactoring, and debugging (Claude Code, GitHub Copilot or equivalent).

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.

BENEFITS

• 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 $124,000-$187,000, based on relevant skills and experience and includes a generous benefits plan.

#LI-AV1

#LoopNet

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