Senior Software Engineer

About Mutinex

At Mutinex, we’re not chasing unicorn status—we’re building a sustainable, long-lasting business (think Bowhead Whale). We're an early-stage B2B SaaS company with a proven platform, trusted by big-name clients, and already generating millions in revenue.

Our mission is bold: to build a universal business growth decision engine. Our platform empowers marketing, media, agency, analytics, and finance teams to organize, analyze, and action data at scale—unlocking and optimizing the true drivers of sustainable growth.

We’re a hybrid team spread across Sydney, Melbourne, and New York. We value open communication, diverse perspectives, and a culture of continuous learning and feedback.

The Role

As a Senior Software Engineer on the DataOS team, you'll be a key technical contributor, responsible for building and scaling DataOS, our core platform for automating data ingestion and processing for Marketing Mix Modelling (MMM).

While your primary focus is building robust and scalable data systems, this role is full-stack in nature. You'll have the opportunity to work across our entire technology stack, contributing to our frontend applications to deliver complete, end-to-end features for our users. You'll apply first-principles software engineering to complex data challenges, taking ownership of a high-impact domain within a fast-growing, product-led startup.

Role Responsibilities

• Platform Architecture and Development: Be a key player in steering the technical design and development of DataOS. You'll architect and build new features, evolve the platform's architecture for scalability and maintainability, and uphold the highest standards of code quality.
• Building Scalable Data Systems: Play a crucial part in the engineering efforts to scale our data processing and warehousing solutions. This involves performance engineering, optimizing distributed systems, and designing infrastructure that can handle terabytes of data efficiently.
• End-to-End Feature Delivery: Take ownership of features from the data processing layer all the way to the user interface. You'll work on both the backend APIs and the frontend components that consume them, ensuring a seamless user experience.
• Automated Data Quality & Observability: Go beyond simple data validation. Design and implement robust, automated frameworks for data quality assurance, error handling, and end-to-end observability across our data platform.
• Performance Optimization: Proactively identify and eliminate performance bottlenecks across the platform, from data ingestion and transformation to storage and retrieval.
• Collaboration and Mentorship: Work within a cross-functional team of product managers, data scientists, and other engineers. Share your expertise with team members, championing best practices through code reviews and technical guidance.

What We're Looking For

• Strong Software Engineering Foundation: You have experience building and maintaining production-grade backend systems and services. You live and breathe software engineering principles like SOLID, design patterns, and building testable, maintainable code. Your experience is in software, applied to the data domain.
• Experience Building Data-Intensive Applications: You have a proven track record of designing, building, and scaling complex, data-intensive systems in the cloud. You understand the unique challenges of distributed systems, concurrency, and handling large data volumes.
• Full-Stack Flexibility: You have experience with, or a strong willingness to work on, modern frontend frameworks (we use React). You understand that delivering a great data product means building the user experience that makes it accessible and useful, and you aren't afraid to get your hands dirty in the UI.
• Modern Tech Stack: You have hands-on experience with modern cloud infrastructure (we use GCP) and infrastructure-as-code (e.g., Pulumi, Terraform). While experience with data orchestrators (e.g., Dagster, Airflow) or transformation tools (e.g., dbt) is valuable, your core strength is in a general-purpose language like Python or Go.
• A Passion for the Craft: You see software engineering as a craft and take pride in your work. This translates into a commitment to building high-quality, reliable, and well-tested software. You don't just write code that works; you write code that is clean, maintainable, and a pleasure for others to work with.
• Growth Mindset: You're eager to learn, take on new challenges, and continue to deepen your technical expertise and impact.
• Excellent Communicator: You can clearly articulate complex technical ideas to both technical and non-technical stakeholders.
• Proactive Problem-Solver: You don't just fix bugs; you identify the root cause and improve the system to prevent future issues.

Why Work With Us?

• Real Customer Impact: Your work directly shapes our platform and the success of our customers
• Challenging, Meaningful Work: Tackle complex data and infrastructure problems at scale
• Autonomy and Ownership: Drive initiatives end-to-end with support when you need it
• Learning and Growth: Collaborate with a thoughtful team of engineers and data scientists who love what they do
• Equity Ownership: All team members receive equity (ESOP)
• Parental Leave: 12 weeks paid leave for the primary carer, and 6 weeks for the secondary carer after 2 years
• Generous Time Off: 20 days of annual leave to start, plus 5 extra days after your first year, and 1 additional day each year after that (up to 30)
• Work from Anywhere: Take your laptop and work from anywhere in the world for up to 6 weeks each year

We’re Committed to Inclusion

Mutinex is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We welcome applicants of all backgrounds, experiences, identities, and abilities.

If you need adjustments or accommodations during the application process, just let us know, we’re happy to support you.

Ready to Join Us?

If this sounds like a place where you’d thrive, we’d love to hear from you. Send us your resume and a short note about why this role excites you—we care more about what drives you than perfect formatting.