Principal Full-Stack Engineer (C# / React / AWS)

Intertek; Sydney; Hybrid; AUD 180,000 - 240,000; Full time

Benefits offered by this job

Hybrid work environment

Office in Sydney CBD near Wynyard

Inclusive team

Professional culture

Job summary

Intertek is seeking a Principal Full-Stack Engineer (C# / React / AWS) in Sydney to shape the future of our web, mobile, and API platforms. This senior role sets standards, drives innovation, and mentors developers across multiple projects while staying hands-on.

You will lead technical direction across front-end, back-end, mobile, and cloud, design scalable APIs, and evolve containerised/serverless workloads with Docker, AWS ECS, and Lambda.

Qualifications

• Experience shaping web, mobile, and API platforms with a mix of front-end and back-end tech.
• Strong leadership for setting development standards and mentoring across multiple teams.
• Hands-on coding alongside architecture decisions and delivery accountability.

Responsibilities

• Set technical direction across front-end, back-end, mobile, and cloud.
• Design scalable APIs and data solutions using MySQL, SQL Server, Redis, and OpenSearch.
• Shape and evolve containerised and serverless workloads (Docker, AWS ECS, Lambda).
• Guide teams using React, Next.js, Vue, C#, .NET, and modern CI/CD pipelines.
• Collaborate with product, UX, QA, DevOps, and analytics teams.

Skills

C#

React

AWS

OpenSearch

Docker

Kubernetes

Next.js

Vue

SQL

CI/CD

Tools

Terraform

AWS ECS

Lambda

S3

RDS

Job description

We are looking for a Principal Full-Stack Engineer (C# / React / AWS) to shape the future of our web, mobile, and API platforms. This is a senior technical leadership role responsible for setting development standards, driving innovation, and ensuring delivery of scalable, high-quality solutions across web, mobile, and API platforms. This role requires hands-on coding expertise, cross-team collaboration, and the ability to mentor and guide developers across multiple projects and technologies.

Set technical direction across front-end, back-end, mobile, and cloud.

Design scalable APIs and data solutions using MySQL, SQL Server, Redis, and OpenSearch.

Shape and evolve containerised and serverless workloads (Docker, AWS ECS, Lambda).

Ensure performance, reliability, security, and clean engineering practices.

Guide teams using frameworks such as React, Next.js, Vue, C#, .NET, and modern CI/CD pipelines.

Support native and cross-platform mobile teams through stable, well-versioned APIs.

Integrate AI-assisted capabilities where useful (e.g., search relevance, summarisation, assistants).

Collaborate across the business

Work closely with product, UX, QA, mobile, DevOps, and analytics teams to deliver cohesive experiences.

Influence architecture, data models, API contracts, and system design decisions.

Ensure consistent instrumentation and analytics across platforms (GA4, GTM).

Mentor & grow the engineering team

Coach developers through code reviews, pairing, and knowledge-sharing.

Champion best practices in coding, testing, observability, and continuous improvement.

Foster a culture of innovation and responsible use of AI tooling.

Deliver with impact

Balance hands-on coding with technical leadership.

Provide visibility on progress, risks, and dependencies across systems.

Ensure high-quality releases with strong testing, monitoring, and performance outcomes.

Data & Storage:

Relational databases: MySQL and SQL Server – schema design, indexing, query optimisation, migration strategies.

Caching: Redis (or compatible) for session, configuration, and application data.

Files/objects in S3 or equivalent.

Search:

OpenSearch/Elasticsearch – index design,analysers, relevance tuning, and query optimisation.

AWS (core services including Lambda, ECS, S3, API Gateway, RDS).

Docker-based development and deployment workflows.

Terraform and CI/CD pipelines, infrastructure-as-code.

Demonstrated ability to innovate, simplify, and deliver impactful solutions at scale.

Additional experience (beneficial, not essential)

• Supporting or integrating with iOS and Android applications, including authentication flows, rate limiting, and feature toggling.
• Instrumentation of web and mobile apps using GA4 and GTM:
• Event and conversion tracking
• Tagging strategies and dataLayer best practices
• Using analytics to guide product decisions
• Working with AI-powered features such as relevance tuning, classification, summarisation, or content generation.
• Designing and iterating on prompts
• Evaluating output quality and safety
• Integrating AI services into APIs and workflows
• Strong architectural and systems design skills.
• Experience with Agile/Scrum environments.

Technical Expertise – across modern frameworks, cloud-native architectures, serverless/container platforms, relational databases, search systems, and observability practices.

Leadership & Collaboration – strong ability to mentor engineers, elevate technical standards, and work effectively across product, UX, QA, DevOps, mobile, and analytics teams.

Innovation & Problem-Solving – proactively introduces new ideas, AI capabilities, tools, and processes; able to simplify complexity and drive meaningful improvements.

Delivery & Communication – excellent prioritisation, time management, and clear communication; able to deliver high-quality outcomes under pressure.

We offer

Hybrid work environment

Centrally Located Office in Sydney's CBD - Right Near Wynyard Station

Great Inclusive Team

Professional Company Culture

Opportunity to expand your experience and work with like-minded professionals.