Senior Full Stack Engineer

Senior Full Stack EngineerEngineering | Sydney, AU | Full-time / HybridReports to: Piers Symons, COO & Co-FounderAbout EarlytradeEarlytrade is a B2B fintech company built for the construction industry. We help general contractors and subcontractors improve cash flow through a platform that gives subcontractors more control over when they get paid and on what terms. The result is a fairer, more transparent way to manage working capital across the construction supply chain.We’re building the financial and workflow infrastructure behind how contractors operate and get paid. This is a role for someone who wants hard backend problems with real consequences: transactional correctness, messy edge cases, high-trust systems, and architecture decisions that directly shape how money moves through the construction supply chain.The RoleWe’re hiring a Senior Full Stack Engineer with a heavy backend emphasis to own the systems that power Earlytrade’s platform. That means the services, APIs, data models, and transactional workflows behind how money moves through the business. You’ll work primarily across Java Spring Boot, Earlytrade’s Node/TypeScript GraphQL layer, and PostgreSQL, with enough frontend involvement to provide true full-stack coverage where needed.You’ll report directly to Piers Symons (COO & Co-Founder) and work closely with our Frontend Engineer and the broader product team. This is a high-ownership role on a lean team, your architectural decisions will ship to production and will matter.What You’ll Build

• The core backend services and business logic powering how Earlytrade moves money and manages high-trust financial workflows
• GraphQL APIs and supporting backend services that give our frontend and internal tools clean, predictable access to the platform
• Data models, migrations, and query patterns across PostgreSQL that keep the system fast, correct, and maintainable as the platform grows
• Secure, auditable payment and financial transaction workflows meeting fintech-grade reliability standards
• Backend infrastructure for our GC and subcontractor portals, including authentication, authorization, and role-based access control
• Internal tooling and admin surfaces that support our operations, finance, and customer success teams
• Frontend components and views in React where full stack coverage is neededResponsibilities
• Design, build, and maintain production-grade Java Spring Boot services and the Node/TypeScript GraphQL APIs that sit alongside them
• Own backend architecture decisions: service structure, data modeling, API contracts, and security patterns across service boundaries
• Write and optimize complex PostgreSQL queries, manage schema migrations, and maintain database performance under load
• Implement GraphQL schemas, resolvers, mutations, and subscriptions with a focus on consistency, performance, and clean integration with the underlying platform services
• Enforce backend quality through comprehensive unit, integration, and contract testing
• Collaborate with the Frontend Engineer on API design and data contracts to ensure clean, predictable interfaces
• Contribute to React frontend development for internal tools or product surfaces when needed
• Participate in code review, architecture discussions, and technical roadmap planning with engineering leadership
• Identify and resolve performance bottlenecks, scaling issues, and reliability risks before they reach production
• Maintain clear technical documentation for APIs, data models, and service dependencies
• Mentor junior and mid-level engineers on backend craft, security practices, and system designRequired Qualifications
• 5+ years of professional software engineering experience, with the majority in backend or full stack roles
• Experience building B2B SaaS or fintech products, particularly in payments, AP automation, procurement, or supply chain finance
• Expert-level proficiency in Java and the Spring Boot ecosystem (Spring Security, Spring Data JPA, Spring MVC)
• Strong, production-tested experience designing and building GraphQL APIs, including schema design, resolver patterns, batching, and caching strategy
• Strong working proficiency in TypeScript and the ability to contribute confidently to service-layer or frontend code where needed
• Deep hands-on experience with PostgreSQL: schema design, indexing, query optimization, and migration management
• Solid working knowledge of React and the ability to build or maintain frontend surfaces independently when needed
• Experience with Apollo (Server and/or Client) in a production environment
• Strong understanding of REST API design principles, authentication (OAuth2/JWT), and API security
• Track record of designing backend systems that handle financial data, transactional workflows, or audit-critical operations
• Experience working in agile teams with Git, CI/CD pipelines, and modern deployment practices
• Clear written communication skills, you can explain architectural decisions to both technical and non-technical stakeholdersPreferred Qualifications
• Familiarity with construction technology platforms (Procore, Trimble, Textura, Corpay, AvidXchange, or similar)
• Experience with event-driven architectures, message queues (Kafka, RabbitMQ, or SQS), or async processing patterns
• Exposure to cloud infrastructure (AWS or GCP): deployment, managed databases, secrets management, observability
• Experience with containerization (Docker) and orchestration (Kubernetes or ECS)
• Familiarity with Redis, workflow-heavy backend systems, or search/observability tooling in production environments
• Familiarity with data warehousing or analytics pipelines for financial reporting
• Prior experience in a senior or lead engineering role at a startup or scale-upOur Stack Today
• Core Backend: Java 17 + Spring Boot 3.2
• GraphQL Layer: Node.js + TypeScript, Apollo Server, type-graphql, and TypeORM
• Database: PostgreSQL + Flyway
• Frontend: React 18 + TypeScript + Vite
• API Consumption: Apollo Client, generated GraphQL types, and typed REST clients where appropriate
• External Integrations: Apache Camel
• Platform Services: Redis, Camunda, MeiliSearch, Sentry, and PostHog
• Testing: JUnit, Jest, Vitest, and integration testing frameworks appropriate to each layer
• CI/CD & Delivery: Bitbucket Pipelines, AWS-hosted services, and Netlify for frontend deliveryWhat We Offer
• Competitive compensation dependent on experience
• Meaningful equity in a fast-growing fintech with a clear path to scale
• Direct access to founders and leadership, your architecture decisions will be heard and acted on
• A product that makes a real difference for small and mid-size subcontractors who depend on cash flow
• A collaborative, low-ego team that takes the craft seriously
• On-site culture in Sydney, AU with flexibility where it countswww.earlytrade.com