Senior Software Engineer, Back end (Opal Platform)

Q-CTRL; Sydney; On-site; AUD 150,000 - 210,000; Full time

Benefits offered by this job

Equity

Flexible schedule

Competitive benefits

Job summary

Q-CTRL is seeking a Senior Back-end Software Engineer to join the Opal Platform team in Sydney. You will own backend APIs and microservices, collaborating with product, design and research to deliver high-impact software across our quantum software products.

You’ll design and ship Python APIs (REST and GraphQL) with a strong focus on quality, reliability and security, while mentoring teammates and advancing AI-assisted development in a scaleup environment.

Qualifications

• 5+ years of professional software development.
• 3+ years Python experience.
• Experience building web APIs (REST/GraphQL) with Django or FastAPI.
• Familiarity with OIDC/OAuth2 (Keycloak).
• Strong testing habits (BDD, automated tests, CI/CD).
• Clear communication across teams.
• Bachelor's degree in CS or equivalent.

Responsibilities

• Design, build, test and document Python APIs and microservices.
• Turn product intent into working software using product stories.
• Use AI coding assistants in daily development while ensuring quality.
• Shape how the team uses AI and guardrails.
• Review PRs with rigour and kindness.
• Improve reliability, performance and security of distributed systems.
• Mentor teammates and share knowledge.

Skills

Python

Web APIs (REST/GraphQL)

Django/FastAPI

CI/CD

Testing (BDD)

AI in development

Mentoring

Communication

Education

Bachelor's degree in Computer Science

Tools

Ray

RabbitMQ

Keycloak

Git

Job description

About the team

At Q-CTRL, Quantum Computing Engineering is a global team of software engineers and infrastructure experts, combining deep technical expertise with a startup mindset to deliver real impact through software innovation. Our work is underpinned by robust standards, and by embracing the three virtues. Our team excels in areas across back-end, front-end, machine learning, and platform engineering.

We transform Q-CTRL’s world-leading technological breakthroughs into commercial software products with applications across defense, research, and industry. We work closely with Product, Design, and Research teams to accelerate the path to quantum advantage worldwide.

About the role

As a Senior Back-end Software Engineer in the Opal Platform team you will be responsible for managing how users and partners can access the Q-CTRL products and how our own services interact with our platform.

You’ll share ownership of the Python APIs and microservices that power Q-CTRL's quantum software products, used by customers worldwide. You’ll work in an AI-native engineering team, where agentic tools handle the routine work so you can focus on design, quality and impact.

What you'll be doing:

• Designing, building, testing and documenting Python APIs (REST and GraphQL) and the microservices and client packages behind our product features
• Turning product intent into working software, using stories (AS A, WHEN, THEN) from the Product team as shared, testable specs
• Using AI coding assistants and agentic workflows daily (e.g. Copilot, Claude Code) for implementation, test generation, refactoring and documentation, while owning the quality of what ships
• Helping shape how the team uses AI: evaluating tools, writing prompts and guardrails, and sharing what works
• Reviewing pull requests with rigour and kindness, including AI-generated code
• Improving reliability, performance and security of our distributed systems
• Mentoring teammates and sharing knowledge openly

Ideally you'll have:

• 5+ years of professional software development, including 3+ years in Python
• Strong experience building web APIs (REST, GraphQL) with Django or FastAPI
• Fluent with AI tools in your development workflow, with good judgement about when to trust, verify or override them
• Experience with OIDC/OAuth2 (we use Keycloak)
• Sound testing habits (BDD, automated tests, CI/CD)
• Clear communication and the ability to communicate with different internal audiences
• Comfort moving fast with thought and empathy in a scaleup environment
• A degree in computer science or equivalent practical experience

It would be fantastic if you have these skills/experience but not essential:

• Experience building with LLMs, agents or MCP
• Microservices and distributed systems (we use Ray and RabbitMQ)
• Curiosity about quantum computing (no physics background required)

About Q-CTRL

Q-CTRL is the global leader in AI-powered quantum control infrastructure software. We build the tools that make quantum technology useful, solving the hardest challenges in quantum computing and quantum sensing to deliver real-world impact.

Founded in 2017, we operate globally with offices in Sydney, Los Angeles, San Francisco, Huntsville, Berlin, and Oxford. Our teams bring together technical and multi-disciplinary expertise across the product lifecycle, and we’re hiring talent to help scale every part of the business. We work quickly to turn cutting-edge science into deployable technology.

In 2024 we raised US$113 million in Series B funding, the largest aggregate investment for a quantum software company. Six months later we delivered the first commercial quantum advantage with Ironstone Opal, our field-validated quantum navigation solution for defense and industry.

At Q-CTRL, we prioritize outcomes over hours. We offer flexibility, equity potential, and competitive benefits that reflect our high-performance culture.

Please be advised that our communications will only come from the @q-ctrl.comdomain. All our active job postings are available on ourcompany website.

To recruitment agencies, we do not accept unsolicited branded profiles and are not responsible for any fees related to unsolicited resumes.