Sr. Fullstack Engineer

As a Senior Software Engineer on our newly formed Supplier Portal team, you’ll play a critical role in building Navan’s first Supplier Portal from 0 to 1. Your mission is to architect and develop a robust, secure, and intuitive self-service platform that empowers our travel suppliers to manage and grow their partnerships with Navan.

This is a unique opportunity to build a foundational, high-impact product from the ground up. You will tackle complex technical challenges involving data models, permissions, integrations, and API design, building a durable supply-side platform that improves partner outcomes and strengthens our two-sided marketplace. You’ll collaborate closely with our product managers, designers, and commercial teams across the globe to deliver a platform that works seamlessly across diverse supplier segments. What You’ll Do

• Build from 0 to 1: Drive the development and contribute to the technical design and architecture of the new Supplier Portal, building foundational core services and scalable features from scratch.
• Solve Complex Problems: Apply deep technical expertise to address large-scale engineering challenges, specifically focusing on complex data models, secure permissioning systems, and seamless partner API integrations.
• Deliver Partner-Facing Solutions: Take end-to-end ownership of features - from initial technical design and development to deployment and post-launch operational support - ensuring an exceptional, frictionless experience for our suppliers.
• Collaborate Across Teams: Work closely as part of a global, cross-functional team, partnering with fellow engineers, product managers, designers, and commercial stakeholders to translate supplier needs into scalable technical solutions.
• Contribute to Engineering Culture: Champion best practices in code quality, system architecture, documentation, monitoring, and testing to establish a strong technical foundation for this new team.
• Learn and Grow: Stay engaged with new technologies and industry trends, bringing a growth mindset and a passion for navigating ambiguity to deliver elegant solutions.

• 4+ years of experience building and scaling complex backend systems in fast-paced, high-growth, or large-scale environments (open to exceptional candidates with less experience).
• 0-to-1 & B2B Experience: Hands-on experience developing and maintaining core business platforms, partner-facing tools, or B2B products. Experience building supply-side tooling for a two-sided marketplace is highly valued.
• Technical Proficiency: Strong proficiency in Java and Spring Boot, with a solid understanding of JVM performance and optimization. Supporting UIs for complex business domains, such as configuring travel policies, visualizing approval chains, and managing user roles/permissions.
• Architecture & Cloud: Deep experience with distributed systems, microservices, and robust API design, including practical expertise with AWS or other cloud platforms.
• Security & Data Modeling: Ability to reason about and design secure integrations, complex permission models, and scalable data architectures.
• Ownership Mentality: A strong track record of delivering production-quality, maintainable code, and supporting features post-release through active monitoring and troubleshooting.
• Collaboration: A collaborative team player with excellent communication skills, able to explain complex technical concepts to both engineering peers and non-technical stakeholders.
• Domain Knowledge: Experience in travel technology (flights, hotels, inventory management, or partner APIs) is a strong plus.
• Education: Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field, or equivalent hands-on experience.

At Navan, “It’s all about the user. All of them.” We’re passionate about providing a seamless one-stop experience for business travelers, no matter how they travel, where they stay, or where they’re going. Our engineers work closely with product managers, designers, and data scientists to build innovative tools and services that provide a frictionless, efficient, and enjoyable traveler experience.