Software Engineer II at CoStar Group

Compensation

$118,000 – $154,000/yr

Setup: Hybrid
Location: Irvine, California
Type: Full-time
Level: not_specified
Posted: Aug 11, 2026

Description

CoStar Group's LoopNet division is looking for a Senior Software Engineer to build scalable, high-quality systems using C#, .NET, and AWS cloud development. The role involves contributing to various products like LoopNet.com, accelerating delivery with AI-driven development practices, and playing a key role in architectural decisions and mentoring engineers.

Required Skills

C#/ .NET
AWS cloud development
AI coding tools
Claude Code
GitHub Copilot
unit testing
performance testing
automated end-to-end tests
APIs
backend systems
software design principles
Vue.js
React in TypeScript
relational database design
MS SQL
MySQL
performance tuning
AWS services
Apache Kafka
Datadog
microservices
distributed systems
Docker
Kubernetes
CI/CD pipelines
DevOps practices
Infrastructure as Code tools
Application security
Git-based workflows
cloud data warehouse platforms
Python for data engineering/analytics workflows

Additional Information

Minimum Education: Bachelor’s degree from an accredited, not-for-profit university or college.
Required Previous Experiences: 4+ 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.
Preferred Qualifications: 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.