Lead AI‑First Software Engineer Greenfield Web App

Lead Software Engineer
- Co Star
- Arlington, VA

Job Description

Overview

CoStar Group 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 to our customers. We’ve continually refined, transformed and perfected 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.

Co Star

CoStar is the global leader in commercial real estate information, analytics and news. Commercial Real Estate industry professionals around the globe use CoStar to access the most comprehensive data to make decisions with confidence. CoStar delivers immediate, verified commercial real estate information on over 5.9 million properties across every market. Learn more about CoStar.

About the Role

As CoStar’s next Lead Software Engineer, you will lead the build of a greenfield, enterprise-scale web application infused with AI
, leveraging modern technologies and frontier models. Drive the development of AI-powered product experiences while shaping AI-first engineering workflows that redefine how software is built. This is a high-impact role to architect, innovate, and influence the future of intelligent applications at scale.

This position is located in Arlington, VA and is in onsite Monday – Thursday, with the option to work from home on Friday.

Responsibilities

• Architect scalable, resilient distributed systems — defining service boundaries, data contracts, and cross-team API standards for an enterprise-scale platform

• Build responsive, high-performance applications using React, Node.js, Tailwind, etc.
• Work with cloud-native services (Azure/AWS/GCP), containers, and microservices
• Optimize for performance, observability, and developer productivity
• Leverage AI Tooling & Automation (CI/Cd, code generation, test generation)
• Influence and establish AI-first engineering practice (vibe coding, human-in-the-loop, debugging)
• Establish AI Culture & Mentorship (team upskilling, lifecycle redefinition)
• Continually evaluate emerging technologies to identify opportunities, trends and best practices that can be used to strengthen CoStar’s technology platform and development practices
• Develop and maintain an in-depth working knowledge of the CRE Industry and CoStar’s business model / technology

Basic Qualifications

• Bachelor’s Degree required from an accredited, not for profit, in-person university or college.
• A track record of commitment to prior employers
• 8+ years of production development experience in modern technologies, like React, Vue, Type Script, NodeJS, C#, .Net, Open Search, Kafka, SQL, No
  
  SQL
• A demonstrable track record of building and launching successful products and platforms
• Experience designing for high availability, horizontal scalability, and production observability at enterprise scale
• Experience with cloud technologies like AWS, Cloud Managed Services, etc.
• Experience in Agile/Scrum processes, and Continuous delivery practices
• Experienced in unit, performance, and automation testing
• Deeply understand what drives the business for which you are building software
• Take an active role in mentoring developers with ability to build consensus

Preferred Qualifications and Skills

• Experience managing a large Enterprise level code base, code quality and dependencies
• Experience with C#, NodeJS, and/or React in particular
• Build Agents and Workflows using modern AI patterns
• Leverage Vibe coding to improve productivity and quality
• Excellent written and verbal communication…