# Senior Software Engineer, Expense

**Company:** [Navan](https://hotfix.jobs/companies/navan)
**Location:** Berlin, Germany, London, United Kingdom
**Role:** Fullstack Engineering
**Experience:** 5+ years
**Skills:** Java, Spring Boot, TypeScript, Python, AWS, Kafka, LLM APIs, Retrieval-Augmented Generation, Document Ocr, Relational Data Modeling, APIs, CI/CD, Observability, Agent Frameworks, Tool Calling
**Posted:** 2026-09-04

> Build production software for Navan’s expense platform across backend, web, and AI services. The role requires 5+ years of software engineering experience, strong Java, TypeScript, or Python skills, and experience shipping LLM-powered or document-extraction features in high-stakes financial workflows.

## Job Description

## Responsibilities
- Design and ship features in backend services using Java and Spring Boot, web applications using TypeScript, and AI services using Python or TypeScript.
- Own APIs and event-driven flows for money, receipts, and policy decisions at company scale.
- Build and extend LLM-backed agents with tool use, grounding, streaming, session memory, retrieval, and evaluations.
- Improve document extraction and automatic itemization, including quality, tax fields, latency, cost, and provider failover.
- Instrument production with observability, quality dashboards, chat satisfaction metrics, and extraction accuracy tracking.
- Partner with Product and Design on employee, administrator, and mobile AI experiences.
- Ensure correctness in financial systems through idempotency, auditability, permissions, and prevention of silent partial writes.
- Mentor engineers and write technical designs for distributed teams.

## Requirements
- 5+ years building production software; 8+ years for Staff-level roles.
- Strong computer science fundamentals.
- Depth in at least one of Java/Spring Boot, modern TypeScript, or Python services, with willingness to work across technologies.
- Experience with relational data modeling, APIs, and cloud platforms such as AWS.
- Experience shipping AI in a production product, including LLM APIs, tool or function calling, retrieval-augmented generation, evaluation, or document/vision extraction.
- Ability to discuss AI failure modes such as hallucination, cost, latency, prompt injection, and PII handling.
- Comfort with financial or workflow-heavy domains such as expenses, payments, ERP, or tax.
- Strong written design and code review skills, with a focus on tests, CI/CD, observability, and incident ownership.
- Based in or willing to relocate to Berlin or London.

## Nice to Have
- Kafka or similar messaging systems.
- Document OCR.
- VAT/GST or multi-currency experience.
- Policy engines.
- Agent frameworks.
- Evaluation platforms.
- Mobile AI user experience.

## Benefits
- Opportunity to work on expense, payments, accounting, and AI products used by companies worldwide.

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