Senior Engineer (Core Web)

CoStar Group; Sydney; On-site; AUD 150,000 - 190,000; Full time

Benefits offered by this job

Extra vacation days

LinkedIn Learning

Perkbox discounts

Job summary

CoStar Group is hiring a Senior Software Engineer in Sydney. You will architect scalable, high-performance systems and lead with modern frontend tech including React, TypeScript and Next.js.

You’ll mentor engineers, collaborate with Product and Design, and own reliability improvements across services to deliver customer-centric outcomes. Ideal candidates bring GraphQL expertise, experience with AWS, Docker, and CI/CD, and a strong focus on web performance and security practices within an Agile

Qualifications

• Degree in Computer Science, Software Engineering, or related discipline.
• Strong frontend expertise with React, TypeScript, Next.js and GraphQL.
• Experience building scalable, high-traffic web apps using modern patterns.
• Proficiency with AWS, Docker and CI/CD practices.
• Collaborative, agile with product/design teams; mentoring experience.
• Security awareness and OWASP familiarity is a plus.

Responsibilities

• Architect scalable, high-performance software and guide technical direction.
• Write and review code; ensure solutions align with engineering strategy.
• Mentor junior engineers and collaborate with Product and Design teams.
• Lead on-call rotations, incidents, and reliability improvements.
• Drive engineering quality and modern best practices across teams.

Skills

React

TypeScript

Next.js

GraphQL

Web performance

Agile

Mentoring

Education

Degree in Computer Science or Software Engineering

Tools

AWS

Docker

CI/CD

Job description

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.

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.

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