Senior Software Engineer II - Backend, APIs & Cloud

CoStar Group, Inc.; Irvine, Northern (CA, KY); Hybrid; USD 118,000 - 154,000; Full time

Benefits offered by this job

Healthcare coverage

401(K) plan with matching

Job summary

LoopNet is seeking a Software Engineer II to contribute to backend services, APIs, and scalable systems within CoStar Group's market-leading platform. You will collaborate with product teams to deliver robust features and ensure performance SLAs, using C# and .NET in a modern, cloud-based environment.

The role emphasizes writing tests, mentoring others, and delivering quality software. You will work with AWS, Docker, Kubernetes, and data tooling, helping to advance LoopNet’s real estate

Qualifications

• Bachelor’s degree from an accredited university.
• 4+ years of production development with C# and .NET/.NET Core.
• Proven track record delivering products and meeting performance SLAs.
• Experience building APIs and backend systems with strong design principles.
• Mentoring developers and contributing to team consensus.

Responsibilities

• Develop and maintain backend services and APIs.
• Ensure software reliability, performance, and scalability.
• Collaborate with product, design, and other engineering teams.

Skills

APIs & backend systems

C# / .NET

Testing (unit, performance, E2E)

Mentoring & team collaboration

AWS services

Docker & Kubernetes

CI/CD & DevOps

Git-based workflows

Security awareness

AI coding tools (e.g., Copilot)

Education

Bachelor’s degree

Tools

Vue.js/React (TypeScript)

MS SQL / MySQL

Kafka

Datadog

BigQuery / Databricks / Snowflake

Job description

LoopNet is seeking a Software Engineer II to contribute to backend services, APIs, and scalable systems within CoStar Group's market-leading platform. You will collaborate with product teams to deliver robust features and ensure performance SLAs, using C# and .NET in a modern, cloud-based environment.

The role emphasizes writing tests, mentoring others, and delivering quality software. You will work with AWS, Docker, Kubernetes, and data tooling, helping to advance LoopNet’s real estate