Job Title:Senior Backend Software Engineer (Java/Kotlin) Location:Brazil, Costa Rica, Colombia Work Mode:100% Remote Employment 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. LeverageAI-assisted development toolsto 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 Javaoranother 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 usingAI-assisted coding toolsin 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 inambiguous, fast-moving, and greenfield environments. Strong ownership mindset and ability to work independently. Excellent communicator and collaborative team player. Open toAI-assisted development workflowsand modern engineering practices.