Senior Engineer (OAuth2)
Job Description
The role of Senior Engineer is pivotal in supporting the delivery of our Domain Strategy by driving innovation and ensuring the development of high-quality software solutions. By leveraging advanced technical skills and a deep understanding of software engineering principles, the Senior Engineer contributes to the creation of robust, scalable, and efficient applications that align with our strategic goals. This role involves not only writing and reviewing code but also architecting solutions that meet both current and future business needs, ensuring Software Solutions supports the overall Domain vision.
In addition to technical expertise, the Senior Engineer plays a crucial role in mentoring and guiding junior team members, fostering a culture of continuous improvement and Engineering excellence. By leading by example and providing support, this role helps build a strong, cohesive team capable of tackling complex challenges and delivering high-quality software products. The Senior Engineer also collaborates closely with cross-functional teams, including product management, to ensure that software solutions are aligned with customer value and business needs.
What you’ll do
Build high quality scalable, reliable and performant solutions in collaboration with other engineers and tech leads.
Keep abreast of latest trends in technology and software engineering. Use responsible engineering principles to understand when and how to apply those same trends.
Champion and adopt Engineering best practices.
Participate in and contribute to cross-domain technology forums such as Architecture Guild and Tech Leadership Guild.
Contribute to the System Health and Tech debt backlog for their respectively owned service.
Champion engineering efficiency for their respective team and services.
Collaborate with Lead Engineers and Tech Leads on improving process and system change.
Mentor more Junior Engineers in Solution design and building high quality solutions.
Be on-call and respond to incidents when raised.
Continuously find ways to improve process and quality of software to reduce incidents over time.
Essential
Bachelor’s Degree in a relevant technical specialisation
Strong experience in C# / .NET 8+ and ASP.NET Core for distributed backend services
Strong understanding of OAuth2, OpenID Connect, and token lifecycle management (PKCE, federation, refresh tokens, assertion grants)
Experience designing software solutions for scale
Experience with high traffic customer-facing services
Experience working with Tech leads to optimise engineering practices and processes
Experience working with one of the common Cloud Platforms such as AWS, Azure, and/or GCP
Experience with microservices and event-driven architectures
Experience with SQL data stores (PostgreSQL, MySQL/Aurora) and NoSQL (DynamoDB, Redis)
DevOps practices, CI/CD, and infrastructure-as-code
Nice to have
Product/application development experience
Experience or familiarity with Duende IdentityServer
Experience migrating or integrating between identity providers
Experience with asynchronous (SNS/SQS, EventBridge) integration patterns
Experience with API gateway platforms — external developer onboarding, usage metering, and credential management
Experience with fine-grained authorization systems (AuthZed/SpiceDB, OpenFGA, or similar)
TypeScript / Node.js for AWS Lambda and infrastructure-as-code (CDK)
React / Next.js or other modern web frontend frameworks
AWS (or other Cloud Platform) Certification
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 [email protected] or leave a message on 1300 858 356 and we will get back to you.
CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing
