Senior Engineer

Senior Engineer Job Description Technical Excellence & Innovation Build high-quality, scalable, reliable, and performant solutions with engineers and tech leads. Champion engineering best practices and contribute to system health and technical debt improvements. Drive engineering efficiency and collaborate with tech leads to improve processes and systems. Leadership & Collaboration Mentor junior engineers in solution design and development. Develop a strong understanding of the product and business domain. Work with Product Managers to ensure solutions meet customer and business needs. Operations Participate in on-call rotations and respond to incidents. Continuously improve processes and software quality to reduce incidents. Experience Designing scalable software, high-traffic websites, and complex mobile apps. Working with Tech Leads to optimize engineering practices. Cloud platforms (AWS, Azure, GCP), DevOps, CI/CD, Agile. Mentoring junior engineers and collaborating with cross-functional teams. Microservices architecture and relational/non-relational databases. Technical Skills Deep expertise in at least one of: Node.js (TypeScript), React (TypeScript), or Python — and comfortable across all three Working knowledge of .NET (C# preferred) — you don't need to be an expert, but you can read, review, and contribute to .NET codebases when needed Strong understanding of REST API design, security best practices, and authentication patterns (JWT, OAuth2, JWKS) Extensive experience with relational databases (PostgreSQL) — including schema design, query optimization, and migrations Proven ability to apply Clean Architecture or similar structured design patterns in a production codebase Strong experience with AWS (EC2, SQS, S3, CloudFront) and cloud-native patterns Experience designing and working with asynchronous/event-driven systems (message queues, background workers) Track record of delivering high-quality features in an Agile environment using Git, CI/CD, Jira, and Confluence Nice-to-have skills: Experience with Auth0 or enterprise identity providers (SSO, M2M, multi-tenant auth) Experience with observability tooling — New Relic, Mixpanel, CloudWatch A security-first mindset — input validation, token verification, least privilege, avoiding common OWASP vulnerabilities Experience leading or significantly contributing to a platform migration or re-architecture Familiarity with containerisation (Docker) and Kubernetes or Helm deployments Education & Certifications Degree in Computer Science/Software Engineering. Bonus: AWS or other cloud certification. Company 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 and the, 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. About Domain: 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 (NASDAQ: CSGP), a global leader in commercial real estate information, analytics, online marketplaces and 3D digital twin technology. Together, Domain and CoStar Group is dedicated to digitising the world's real estate, empowering all people to discover properties, insights, and connections that improve their businesses and lives. What's Next? We'll give your application the thoughtful attention it deserves and get back to you as soon as possible. If there's a match, one of our recruitment consultants will reach out-so keep your phone handy! We're genuinely excited about the chance to work together and make a meaningful impact. 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 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. CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing