Job Title: Senior Backend Software Engineer (Java/Kotlin)Location: Brazil, Costa Rica, ColombiaWork Mode: 100% RemoteEmployment Type: Independent Contractor (Hourly, no benefits, candidate responsible for taxes)Contract Duration: 6 Months (with possibility of extension)Working Hours: 40 hours per weekRole Overview- Senior Software Engineer on a newly formed Item Domain team (Sales & Retail: Pricing, Pay, and Merch Tools) for an authenticated luxury resale marketplace.- Focus on rebuilding core item data systems (pricing, merchandising, enrichment) through a mix of greenfield development and legacy system integration.- This is a high-impact role contributing to a long-term transformation of core data systems, leveraging modern backend technologies and AI-assisted development.- Collaborate closely with product, design, and engineering leadership in a fast-moving, cross-functional environment.Key Responsibilities- Produce high-quality, performant, and testable code contributing to company-wide initiatives.- Develop backend services and internal tooling using JVM (Java, Kotlin) as a core focus, along with existing systems in Python and Ruby.- Build and support web applications for shoppers and operators (listing, enrichment, merchandising).- Work with technologies including React, TypeScript, GraphQL, Kafka, AWS/Lambda, PostgreSQL, DynamoDB.- Contribute to technical decisions shaping future software systems and architecture.- Review pull requests and provide constructive feedback to peers.- Collaborate through pair programming and support onboarding when needed.- Deploy user-facing code to production responsibly.- Partner closely with product managers, engineering leadership, and stakeholders across regions.- Ensure observability and reliability by learning from metrics and incidents and maintaining systems.- Leverage AI-assisted development tools to improve productivity and engineering workflows.- Continuously learn and apply new technologies, patterns, and initiatives.Required Qualifications- Bachelor’s degree in Computer Science or equivalent experience.- 3–5+ years of strong backend software engineering experience.- Experience with Java or another backend language, with willingness to work with Kotlin (JVM-based systems).- Experience building and maintaining production-ready, reliable, and secure systems.- Understanding of APIs, distributed systems, and event-driven architectures (e.G., Kafka).- Strong communication skills with product, stakeholders, and engineering peers (fluent English required).- Comfortable working cross-functionally with distributed and US-based teams.- Familiarity with RESTful APIs, Git, TypeScript, version control, and deployment tools.- Strong problem-solving mindset with focus on user impact and business context.- Openness to using AI-assisted coding tools in daily development workflows.Preferred Qualifications- Experience with JVM services (Java, Kotlin) in production environments.- Experience with Python or Ruby.- Experience with web technologies: JavaScript, TypeScript, HTML, CSS, React.- Experience building microservices and working across distributed systems.- Experience integrating LLMs or managed AI APIs into backend or internal tools.- Experience with eCommerce platforms.- Experience working with CMS tools (especially Prismic).- Experience with monitoring, dashboards, and incident response in production.What We’re Looking For- Backend-strong engineer (full-stack experience is a plus).- Adaptable and fast learner with flexibility across technologies.- Comfortable working in ambiguous, fast-moving, and greenfield environments.- Strong ownership mindset and ability to work independently.- Excellent communicator and collaborative team player.- Open to AI-assisted development workflows and modern engineering practices.