Senior Software Engineer – React + Rails Architect

CoStar Group; City of Yarra; On-site; AUD 150,000 - 190,000; Full time

Job summary

CoStar Group is seeking a Senior Software Engineer to join the Keystone Squad within the Agent Workflows crew. You will work across a React TypeScript frontend and Ruby on Rails backend, delivering features and infrastructure used daily by thousands of agents across Australia and New Zealand.

You will own design, tests, production monitoring, and help elevate the engineering team. Strong TypeScript and React experience is essential, along with solid Rails experience or willingness to ramp up

Qualifications

• : 5+ years in software engineering with senior-level experience in production systems.
• Strong TypeScript and React: own frontend features end-to-end with confidence
• Solid backend engineering in Ruby on Rails, or comparable framework with willingness to ramp up on Rails
• Deep PostgreSQL experience: query optimisation, indexing, migrations, performance analysis
• Demonstrated ability to design solutions upfront with ADRs or architectural decisions
• Track record of improving team quality through code reviews, mentoring, documentation, or process improvement
• Comprehensive testing practice across unit, integration, and end-to-end layers (Jest, RSpec, Cypress)
• Production observability tooling experience (NewRelic, CloudWatch)
• Strong written communication: PRs, tickets, and technical documentation

Responsibilities

• Own frontend features end-to-end with confidence, from component design to production monitoring.
• Collaborate on Rails backend development and RESTful API design with other squads.
• Write tests to ensure confidence across unit, integration, and end-to-end levels.
• Participate in system design, ADRs, and architectural decisions.
• Improve team quality through code reviews, mentoring, and documentation.
• Ensure production observability and monitoring with appropriate tooling.

Skills

TypeScript

React

Ruby on Rails

PostgreSQL

Testing (RSpec/Cypress)

AWS

CI/CD

RESTful APIs

Software design

Tools

RSpec

Cypress

Sidekiq

Redis

Terraform

AWS

Job description

CoStar Group is seeking a Senior Software Engineer to join the Keystone Squad within the Agent Workflows crew. You will work across a React TypeScript frontend and Ruby on Rails backend, delivering features and infrastructure used daily by thousands of agents across Australia and New Zealand.

You will own design, tests, production monitoring, and help elevate the engineering team. Strong TypeScript and React experience is essential, along with solid Rails experience or willingness to ramp up