Senior Software Engineer - LoopNet
About The Position
CoStar Group is a leading global provider of commercial and residential real estate information, analytics, and online marketplaces. LoopNet, the most popular place to find a space, is the #1 global commercial real estate marketplace. 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.
Requirements
- 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.
Nice To Haves
- 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.
Responsibilities
- Contribute to building scalable, high-quality systems across multiple products and brands—including LoopNet.com.
- Leverage modern AI-driven development practices to accelerate delivery and improve code quality.
- Play a key role in architecture decisions.
- Mentor engineers across the team.
Benefits
- Generous compensation and performance-based incentives.
- Internal training.
- Tuition reimbursement.
- 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.
- 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.
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What This Job Offers
Job Type
Full-time
Career Level
Senior
