Permanent | Hybrid | Sydney

Reports to VP of Engineering About Us

Checkbox is a Series A, Sequoia-backed technology start-up with a mission to enable meaningful work for all. We are building an AI-first platform that is transforming how in-house legal teams operate, from how work enters legal through to how it is understood, routed, managed and resolved. Our customers include leading in-house legal teams at companies such as SAP, Coca-Cola, Allianz, BMW, Elastic and Stryker.

We are now expanding beyond workflow automation into AI-powered intake, matter management, triage and work orchestration. Our vision is to become the Legal Service Hub for modern organisations, responsible for how legal work is raised, allocated, managed and resolved.

As we scale our product, engineering organisation and AI capabilities, we need our architecture to stay coherent, secure and built for the future. This role sits at the centre of that. The Role

We are looking for a hands-on Principal Engineer to act as the senior technical authority across Checkbox’s product engineering streams. This role is accountable for making, recording and governing the key technical decisions that shape our future-state product architecture. That includes high-consequence, hard-to-reverse “one-way-door” decisions that are expensive to undo and should not be made implicitly inside a single team.

You will help keep our architecture sound, coherent across product streams and safe as we scale. Just as importantly, you will ensure key decisions are written down, understood and followed, rather than lost in tribal memory. This is a technical leadership role, not a people-management role.

You will influence through judgement, clarity and working code. What You’ll Own

Own key architecture decisions across Checkbox’s product engineering streams, including high-consequence one-way-door decisions

Define, document and govern the future-state product architecture





Ensure architecture remains coherent across product streams, Platform, Data Engineering, QA, Enterprise IT and other technology teams

Identify, design and help build force-multiplier initiatives that help engineering teams move faster and ship higher-quality software

Contribute directly to production releases and set the technical bar through working code

Drive engineering decisions through data, feedback loops and measurable quality signals rather than opinion alone

Embed fitness functions, architecture measures and technical feedback loops into how product engineering works

Partner closely with the Data Engineering function on the data and AI reference architecture

Ensure tenancy, security and compliance are designed into systems from the start

Work closely with Product, Customer Success and Sales so architecture decisions reflect real customer and commercial needs

Support teams in making pragmatic technical trade-offs between speed, scale, quality, security and maintainability About You

Significant experience as a Principal Engineer, Staff Engineer, Architect or senior technical leader in a modern SaaS environment

Deep systems expertise across product engineering, platform architecture, distributed systems and modern cloud-native software

Strong track record of making and governing high-impact architecture decisions across multiple teams or product areas

Proven ability to design and ship force-multiplier technical initiatives that improve engineering velocity, quality or reliability

Comfortable contributing to production systems while also setting broader technical direction





Strong understanding of tenancy, security, compliance and data isolation in enterprise SaaS environments

Experience working closely with platform, data, QA, infrastructure or enterprise IT teams

Strong product and customer judgement, with the ability to connect technical decisions to commercial and customer outcomes

Ability to influence through credibility, clarity and working code rather than formal authority

Excellent communication skills, with the ability to bring technical and non-technical stakeholders along

Pragmatic, hands-on and comfortable operating in a fast-moving scale-up environment Bonus Points

Experience working on AI-native products, agentic systems, workflow automation or enterprise legal technology

Experience defining architecture across multiple product streams or a multi-product SaaS ecosystem

Experience designing systems that rely on context, retrieval, eventing, integrations or AI-enabled workflows

Experience partnering with data engineering teams on AI or data reference architecture

Experience introducing engineering fitness functions, architectural decision records, technical standards or quality measures

Experience working in a Series A, Series B or high-growth scale-up workplace What We Offer

Competitive salary

Hybrid working with team days in our Sydney CBD office

High ownership over architecture decisions that shape Checkbox’s product and engineering future

Direct impact across product engineering, platform, data and AI systems

Opportunity to help scale an AI-first SaaS platform used by leading enterprise legal teams

Personal learning and development budget

Flexible leave policy

Expense policy and salary sacrifice options

CBD start-up hub with snacks, drinks, premium coffee and team socials

Company-wide social events and annual off-sites

Transparent, flat culture where questions and feedback are welcomed

📌 Principal Software Engineer (Sydney)
🏢 Checkbox
📍 Sydney