Hybrid Senior Full-Stack Engineer AI-Driven Platform

CoStar Group; Arlington (VA); On-site; USD 143,000 - 187,000; Full time

Benefits offered by this job

Healthcare benefits

401(k) retirement plan with matching

Employee stock purchase plan

Paid time off

Tuition reimbursement

On-site fitness center

Job summary

CoStar Group is seeking a Senior Software Engineer for the Platform Development team in Arlington, VA. You will build distributed, API-driven systems and integrate AI-driven workflows across CoStar brands, applying TypeScript, C#, .NET, SQL Server, and AWS.

The role emphasizes business understanding and delivering robust, scalable software in an AI-focused environment. The position is in-office Monday-Thursday with Friday remote, offering competitive base compensation and opportunities for

Qualifications

• Bachelor's degree in a related field.
• 3+ years of .NET (C#) development experience including web APIs and services.
• 5+ years of TypeScript and modern frontend/backend JS tooling (e.g., Node, Vite, React).
• Experience with Terraform and cloud platforms (AWS or Azure).
• Experience building large-scale distributed systems and services in an agile environment.
• Familiarity with LLMs, context engineering, or agent-based architectures.
• Experience with monitoring, telemetry, observability, or automated diagnostics.

Responsibilities

• Build big, distributed, API-driven systems for tens of thousands of users.
• Integrate AI skills, agents, tools, and intelligent workflows across CoStar brands.
• Write robust, efficient, and maintainable code using TypeScript, C#, .NET, SQL Server, AWS.
• Develop customer-facing and internal web apps with React/TypeScript.
• Apply AI models to improve observability, diagnostics, and reliability.
• Drive software design, development standards, and code reviews.
• Collaborate with Product/Research/Data teams to identify AI-driven business value.

Skills

C#

TypeScript

Distributed systems

Terraform

AWS

Azure

LLMs / AI workflows

Observability

Data governance

Education

Bachelor's Degree in Computer Science or related field

Tools

React

Node.js

SQL Server

Kubernetes

Datadog

Kafka

DynamoDB

SQS

EKS

ECS

Job description

CoStar Group is seeking a Senior Software Engineer for the Platform Development team in Arlington, VA. You will build distributed, API-driven systems and integrate AI-driven workflows across CoStar brands, applying TypeScript, C#, .NET, SQL Server, and AWS.

The role emphasizes business understanding and delivering robust, scalable software in an AI-focused environment. The position is in-office Monday-Thursday with Friday remote, offering competitive base compensation and opportunities for