Senior Engineer

CoStar Group, Inc.; City of Melbourne; On-site; AUD 120,000 - 170,000; Full time

Benefits offered by this job

Extra leave days

Leadership development programs

LinkedIn Learning

Perkbox discounts

Job summary

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

You’ll own design before coding, build tests for confidence, and monitor production after release. You are a force multiplier, not just a contributor, driving quality and collaboration across the team.

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 a comparable framework with willingness to ramp up on Rails quickly.
• Deep PostgreSQL experience: query optimisation, indexing, migrations, and performance analysis.
• Demonstrated ability to design solutions upfront with ADRs/architectural decisions.
• Track record of improving team quality through code reviews, documentation, or process improvement.
• Comprehensive testing across unit, integration, and end-to-end layers (Jest, RSpec, Cypress).
• Proficient in production observability tooling (NewRelic, CloudWatch).
• Strong written communication: PRs, tickets, and technical documentation.

Responsibilities

• Rails internals: deep ActiveRecord and background jobs (Sidekiq) understanding.
• Experience ramp-up on Rails quickly; contribute to design before coding.
• Database: query optimisation, joins, indexing, migrations, constraints.
• Security: OWASP Top 10, data protection, auth/authorisation patterns.
• Testing: ensure coverage across unit/integration/e2e with relevant tools.
• Observability: structured logging, error handling, and production monitoring.
• Frontend (primary): production-grade React with TypeScript, performance tuning.
• Infrastructure: AWS, CI/CD pipelines, Terraform basics, secrets management.

Skills

TypeScript

React

Rails

PostgreSQL

Design docs

Code reviews

Testing

Observability

AWS

CI/CD

Tools

RSpec

Cypress

New Relic

Terraform

Sidekiq

Redis

Git

Job description

Senior Engineer

Job Description

We're looking for a Senior Software Engineer to join the Keystone Squad within our Agent Workflows crew. You'll be working 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. Strong TypeScript and React experience is essential. Solid backend engineering and the ability to ramp up quickly on Rails are equally important. At this level, we expect you to own more than your ticket. That means thinking about design before writing code, building tests that give you and your team genuine confidence, monitoring production after you ship, and making the engineers around you better. You are not just a contributor; you are a force multiplier.

What you’ll do Rails internals:

• Deep understanding of ActiveRecord, complex background job processing (Sidekiq), RESTful API design, and modular architectural patterns including service objects and Rails engines.
• Strong candidates with experience in comparable frameworks (Python/Django, Elixir/Phoenix) who can ramp up on Rails quickly are equally welcome.
• Database expertise: Query optimisation, complex joins and views, indexing strategies, query plan analysis, schema and data migration strategies; working knowledge of constraints, triggers, and stored procedures.
• Security: Rails and web security best practices including OWASP Top 10, data protection, user authentication and authorisation patterns.
• Testing: Comprehensive test coverage across unit, integration, and end-to-end layers using RSpec and Cypress; writes tests that build confidence, not just coverage.
• Observability: Structured logging, error handling, and APM tooling (NewRelic or equivalent); knows how to read what's happening in production.
• Frontend (primary): Deep, production-proven experience with React including hooks, Context API, and state management patterns; TypeScript for type-safe development; performance optimisations including memoization, lazy loading, and code splitting.
• Infrastructure: Comfortable with AWS services, CI/CD pipelines with automated testing and deployment, Terraform basics, and secrets management best practices.

Essential:

• 5+ years in software engineering with meaningful senior-level experience in production systems
• Strong TypeScript and React: you can own frontend features end-to-end with confidence, from component design to production monitoring
• Solid backend engineering in Ruby on Rails, or a comparable framework (Python/Django, Elixir/Phoenix) with a genuine willingness to ramp up on Rails quickly
• Deep PostgreSQL experience: query optimisation, indexing, migrations, and performance analysis
• Demonstrated ability to design solutions upfront, with examples of design docs, ADRs, or architectural decisions you've led
• A 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 or equivalent)
• Comfortable with production observability tooling (NewRelic, CloudWatch, or equivalent)
• Strong written communication: clear PRs, tickets, and technical documentation

Nice to have

• Prior Ruby on Rails experience in production
• Experience with Sidekiq, Redis, and background job architecture
• Familiarity with AWS services (RDS, SQS, S3, ECS) and Terraform
• Experience with feature flagging systems (Flipper) and progressive rollout strategies
• Real estate, proptech, or high-volume B2B SaaS domain experience
• Experience with API integrations across diverse payload formats (XML feeds, CRM integrations, vendor APIs)

What’s In It For You?

Working at CoStar Group means you'll enjoy a culture of collaboration and innovation that attracts the best and brightest across a broad range of disciplines. We offer you generous compensation and performance-based incentives.

As well as having an outstanding working environment, other perks include extra days of annual leave, leadership development programs, LinkedIn Learning, Perkbox discounts and much more!

At CoStar, we recognise the positive value of diversity and promote equality. We aim at all times to recruit the person who is most suited to the job and welcome applications from people of all backgrounds including but not limited to; people of all genders, of all ages, sexual orientations, ethnicities, nationalities, religions and beliefs.

About Domain (part of the CoStar Group)

Domain is a leading property technology and services marketplace that is home to one of the largest portfolios of property brands in Australia, including the Domain, Allhomes and Commercial Real Estate (CRE) platforms. In 2025, Domain became part of CoStar Group - a global leader in commercial real estate information, analytics, online marketplaces and 3D digital twin technology. We are dedicated to digitising the world’s real estate, empowering all people to discover properties, insights, and connections that improve their businesses and lives.

Equity, Diversity & Inclusion

Domain is enthusiastically and unapologetically committed to fostering an equitable, inclusive work culture which reflects our customers and communities. We are proactively looking for candidates from all lived experiences, including people with disability, and people of all ages, ethnicities, cultures (including Aboriginal and Torres Strait Islander Peoples), faiths, sexual orientations, and gender identities (including trans and non-binary people). We are committed to providing an equitable recruitment process for people with disability. If you require adjustments during the process we’re here to support. If you wish to receive this job advertisement in an accessible format, or have a confidential chat about workplace adjustments, please contact our Equity, Diversity and Inclusion team at [e-mail] or leave a message on 1300 858 356 and we will get back to you.

Equal Employment Opportunity

CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing.

CoStar Group (NASDAQ: CSGP)

CoStar Group (NASDAQ: CSGP) 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 37 years, giving us the perspective to create truly unique and valuable products and services. We’ve continually refined, transformed and perfected our approach to our business, creating a language that has become standard in our industry and for our customers. 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. CoStar Group is committed to creating a diverse environment and is proud to be an equal opportunity workplace and affirmative action employer.

Hiring Policy

All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.

Compliance with fair employment practices

CoStar Group is also committed to compliance with all fair employment practices regarding citizenship and immigration status. If you are a qualified individual with a disability or a disabled veteran, you may request a reasonable accommodation if you are unable or limited in your ability to use or access www.costargroup.com/careers as a result of your disability. You can request reasonable accommodations by sending an email to [e-mail].