Senior Engineer (Core Web)

CoStar Group, Inc.; Sydney; On-site; AUD 140,000 - 190,000; Full time

Benefits offered by this job

Extra days of annual leave

Leadership development programs

LinkedIn Learning

Perkbox discounts

Job summary

CoStar Group, Inc. is seeking an Senior Engineer (Core Web) in Sydney to drive high-quality software development and architectural decisions.

You will lead the frontend stack with React, TypeScript, and Next.js, building scalable, high-traffic web applications while mentoring junior engineers and aligning with product goals. You will optimise Core Web Vitals, collaborate with product and design teams, and contribute to platform reliability and security.

Qualifications

• Degree in Computer Science, Software Engineering, or a related discipline.
• Strong expertise in modern frontend technologies, including React, JavaScript, TypeScript, and Next.js.
• Experience building scalable, high-traffic web applications using modern architectural patterns such as Micro Frontends, SPA, and SSR.
• Experience working with GraphQL, cloud-native technologies (AWS), containerisation (Docker), and modern CI/CD practices.
• Proficiency in designing and delivering high-quality software solutions within Agile development environments.
• Collaborative mindset with proven experience working across Product, Design, and Engineering teams to deliver customer-focused outcomes.
• Demonstrated ability to mentor junior engineers, contribute to engineering best practices, and drive continuous improvement within development teams.
• Security: Familiarity with modern Application Security Practices (OWASP) preferred.
• Deep understanding of web performance optimisation, including Core Web Vitals (INP, LCP, CLS, and TTFB).

Responsibilities

• Build high-quality, scalable, and reliable solutions, applying modern engineering best practices and contributing to continuous improvement across the technology landscape.
• Demonstrate strong expertise in web performance optimisation, including Core Web Vitals (LCP, INP, CLS, and TTFB), with a focus on delivering exceptional customer experiences.
• Contribute to the health, stability, and evolution of platforms by addressing technical debt, improving system performance, and influencing engineering standards through collaboration with broader technical communities.
• Mentor and support junior engineers, while partnering closely with Product Managers and Designers to deliver customer-centric outcomes aligned with business goals.
• Take ownership of operational excellence, including participating in on-call rotations, responding to incidents, and proactively improving system reliability, security, and maintainability.

Skills

React

TypeScript

Next.js

Web performance

Mentoring

Agile

Education

Degree in Computer Science or related field

Tools

GraphQL

AWS

Docker

CI/CD

Job description

Senior Engineer (Core Web)

Job Description

Senior Software Engineer will drive high-quality software development and innovation, serving as a key driver of technical direction across engineering initiatives. This pivotal role involves architecting scalable, highly performant software systems, writing and reviewing code, and ensuring all technical solutions align with the broader engineering strategy. Leveraging deep expertise in React, TypeScript, and Next.js, the engineer will lead the development of complex features, mentor team members, and champion engineering quality standards to solve real customer problems and enhance web applications.

What you’ll do

• Build high-quality, scalable, and reliable solutions, applying modern engineering best practices and contributing to continuous improvement across the technology landscape.
• Demonstrate strong expertise in web performance optimisation, including Core Web Vitals (LCP, INP, CLS, and TTFB), with a focus on delivering exceptional customer experiences.
• Contribute to the health, stability, and evolution of platforms by addressing technical debt, improving system performance, and influencing engineering standards through collaboration with broader technical communities.
• Mentor and support junior engineers, while partnering closely with Product Managers and Designers to deliver customer-centric outcomes aligned with business goals.
• Take ownership of operational excellence, including participating in on-call rotations, responding to incidents, and proactively improving system reliability, security, and maintainability.

Ideally you’ll have

• Degree in Computer Science, Software Engineering, or a related discipline.
• Strong expertise in modern frontend technologies, including React, JavaScript, TypeScript, and Next.js.
• Experience building scalable, high-traffic web applications using modern architectural patterns such as Micro Frontends, SPA, and SSR.
• Experience working with GraphQL, cloud-native technologies (AWS), containerisation (Docker), and modern CI/CD practices.
• Proficiency in designing and delivering high-quality software solutions within Agile development environments.
• Collaborative mindset with proven experience working across Product, Design, and Engineering teams to deliver customer-focused outcomes.
• Demonstrated ability to mentor junior engineers, contribute to engineering best practices, and drive continuous improvement within development teams.
• Security: Familiarity with modern Application Security Practices (OWASP) preferred.
• Deep understanding of web performance optimisation, including Core Web Vitals (INP, LCP, CLS, and TTFB).

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.

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) 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. 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. 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].