LoopNet - Software Engineer II

Company Overview

CoStar Group (NASDAQ:CSGP) is a leading provider of commercial and residential real estate information, analytics, and online marketplaces. Loop Net is the #1 global commercial real estate marketplace.

A Senior Software Engineer with deep expertise in C#/.NET and AWS cloud development, responsible for building scalable systems across Loop Net and other products. The role leverages AI‑driven development practices, participates in architecture decisions, and mentors engineering teammates. Based in Irvine, CA with a hybrid schedule (4 days onsite, 1 day remote).

• Design, develop, and deploy high‑quality, scalable systems across multiple Loop Net products.
• Apply modern AI coding tools (Claude Code, Git Hub Copilot) to accelerate delivery and improve code quality.
• Make key architecture decisions and enforce best practices across the engineering team.
• Mentor junior developers and foster technical consensus.
• Write robust unit, performance, and end‑to‑end tests, and maintain high code coverage.

• Bachelor’s degree from an accredited, not‑for‑profit institution.
• 7+ years of production development experience with C# and .NET (or .NET Core).
• Demonstrated history of building and launching successful products and platforms.
• Experience delivering products that meet specifications and performance SLAs.
• Solid experience building APIs and back‑end systems with strong software design principles.
• Deep understanding of business context for which software is built.
• Active participation in mentoring developers and building team consensus.

• Working knowledge of Vue.js or React with Type Script.
• Experience with relational database design (MS SQL or MySQL) and performance tuning.
• Hands‑on experience with AWS services (S3, SQS, DynamoDB, Elasti Cache), Apache Kafka, and Datadog.
• Experience with microservices, distributed systems, Docker, and Kubernetes.
• Familiarity with CI/CD pipelines, Dev Ops practices, and Infrastructure as Code tools.
• Knowledge of application security and Git‑based workflows.
• Professional experience with AI coding tools (Claude Code, Git Hub Copilot, etc.).
• Experience with cloud data warehouse platforms (Big Query, Databricks, Snowflake) and proficiency in Python for data engineering or analytics.

Base salary: $118,000–$154,000 annually. Salary is based on location, skills, and experience.

• Comprehensive health, vision, dental, and prescription coverage.
• Life, legal, and supplemental insurance.
• Virtual and on‑site mental health counseling.
• Commuter and parking benefits.
• 401(k) retirement plan with matching contributions.
• Employee stock purchase plan.
• Paid time off.
• Tuition reimbursement.
• On‑site fitness center or reimbursed membership (location dependent).
• Employee Resource Groups.
• Complimentary healthy snacks and beverages.

CoStar Group is an Equal Employment Opportunity 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. The company is committed to fair employment practices regarding citizenship and immigration status and to providing reasonable accommodations for qualified individuals with disabilities.
Applicants must be eligible to work full‑time in the United States. Visa sponsorship is not available for this role.