Lead Full Stack Developer

As a Lead Full Stack Developer, you will:

• Lead hands-on development across front-end, back-end services, APIs, integrations and cloud infrastructure.
• Design and evolve the architecture and data models behind matching, search, reporting and analytics.
• Build and improve AI-powered matching between supply and demand on the platform.
• Design scalable REST APIs and integrations with logistics providers, partner platforms and external data sources.
• Develop responsive web workflows and dashboards that track transactions from offer through delivery.
• Set engineering standards through code reviews, automated testing, CI/CD, observability and security practices.
• Work with product, operations and leadership on technical discovery, estimation and solution design.
• Mentor developers, troubleshoot complex production issues and take part in incident response.

Requirements:

• At least 7 years of professional software development experience, including substantial hands-on full-stack work
• Strong back-end and service-oriented architecture skills, covering APIs, business logic, data access and distributed systems
• Modern front-end experience building responsive web applications with intuitive user experiences
• Proven experience designing, testing and scaling production-grade REST APIs and integrations
• Solid relational database knowledge, including data modeling and query optimization
• Strong communication skills and fluent English, spoken and written
• Hungarian citizenship (dual citizenship is also accepted).

Development knowledge of as many of the following technologies as possible:

• Java, Spring Boot, Spring MVC, Spring Data
• React or another modern JavaScript/TypeScript framework
• AWS or another major cloud platform
• Docker and containerized, cloud-native architectures
• CI/CD pipelines, automated testing, observability tooling
• AI/LLM APIs and retrieval-augmented generation (RAG)

Nice to Have:

• Experience building marketplace, SaaS, e-commerce, logistics or other multi-party platforms
• Event-driven architectures, microservices and asynchronous processing
• Integrating CRM/ERP systems, logistics platforms or external data providers
• Building reporting, analytics dashboards or data pipelines for operational decision-making
• Working in regulated environments where security, auditability and traceability matter

At HexaIO we are looking for a hands-on Senior Lead Full Stack Developer for one of our international technology clients. The client is building a multi-party marketplace platform that connects suppliers, partner organizations and logistics providers. You will lead the architecture and write production code, and you will also set engineering standards and mentor other developers.

Intelligent, AI-powered matching is a core capability of the product. It is a strong advantage if you use AI-based development tools (e.g., Claude, GitHub Copilot, Cursor, or similar solutions) every day and can apply them productively across the whole development lifecycle.