Senior Engineer (Core Web)

CoStar Group; 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's Domain in Sydney seeks a Senior Engineer (Core Web) to lead frontend architecture and deliver scalable web applications. You will drive performance optimisations, mentor engineers, and collaborate with Product and Design to ship customer-centric features.

The role combines hands-on coding with technical leadership, focusing on robustness, security, and maintainability in a fast-paced, inclusive environment. Strong expertise in React/Next.js is essential.

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

JavaScript

TypeScript

Next.js

Web performance optimization

Agile development

Mentoring

Cross-functional collaboration

OWASP security awareness

Education

Degree in Computer Science, Software Engineering, or a related discipline

Tools

Docker

AWS

CI/CD

GraphQL

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.

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