Senior Backend Developer (Java/Spring Boot)

Quick Summary ⏰ Start Date: ASAP 🎯 Project Focus: Build the "Central Operating System" for Latin American convenience stores (bodegas). You will replace manual notebooks with a high-performance, AI-integrated retail engine. 🕛 Hours: Full-time 🌎 Location: Fully remote 🇪🇺 Time Zone: Looking for people in Europe or LATAM 🇬🇧 Language: Native or professional English required. Spanish is a strong bonus, as the project is targeting the Latin American market. 🤠 5+ years of experience in backend engineering. Expert-level Java 21 (LTS), Spring Boot 3.2+, and PostgreSQL . Experience with Event-Driven Architecture and DDD is required. 💸 Salary Range: €3,000 - €4,000/month gross (dependent on experience level) About Afternow We are partners in your digital journey. We bring together strategy, design, and technology to build systems that flex as your future unfolds. Afternow creates the digital systems brilliant companies are built on. Strategy, identity, web and product design, and technology that scales. Every part of the process supports and informs the other, creating an environment that works today and adapts to wherever the business goes next. We work primarily with ambitious, digitally focused organizations navigating change. From startups finding their footing, to scale-ups building momentum, to established enterprises reshaping their digital foundations. Our partnerships are built on clarity, craft, and care. Since 2012, we've grown from our roots on Island Krk, Croatia, to a fully remote team of more than thirty talented people working across the globe. We've partnered with companies including AWS, ThoughtSpot, Progressive, Descartes, ShipBob, Quillbot, Teachable, Crisp, CloudZero, Kinetik, and many more. 🏆 4.6 Glassdoor Rating - Join our team and discover why our people consistently rate us so highly. The Role We are looking for a passionate Senior Backend Developer to join the foundational team for our digital retail ecosystem. You will be responsible for building high-scale microservices that power real-time retail POS transactions, B2B marketplace logic, and AI-driven inventory insights. Your challenge is to implement complex Domain-Driven Design (DDD) patterns to bridge the gap between sophisticated agentic AI and the practical needs of small store owners. What You'll Do Core Logic Implementation: Write clean, testable, and efficient Java 21 code using Spring Boot 3 . Leverage Project Loom (Virtual Threads) to handle high-concurrency retail workloads. DDD & Microservices : Develop stateless REST APIs within a microservices architecture (gateway), adhering strictly to bounded contexts and URI path versioning. Database Performance: Design and optimize complex SQL queries for Amazon Aurora PostgreSQL . You will design schemas that handle high-frequency POS transactions while ensuring read replicas are optimized for AI reporting queries. The "Offline-First" Sync: Design robust logic to synchronize data from local SQLite mobile databases to the cloud, ensuring data integrity for store owners with intermittent internet. Event-Driven Development: Build asynchronous workflows using Kafka . Fintech & Payments: Implement logic for split payments, QR code integrations, and informal credit management with automated limits. Testing Culture: Maintain high test coverage. You believe that code without tests is technical debt. Code Review: Actively participate in PR reviews, ensuring your peers adhere to coding standards and security practices. What We're Looking For 5+ years of backend development experience in a professional environment. Modern Java Stack : Expert knowledge of Java 21, Spring Boot 3.2+, Hibernate , and Virtual Threads (Project Loom). Architecture: Deep understanding of Domain-Driven Design (DDD) and Event-Driven Architecture (EDA). AWS Familiarity: Experience running applications in AWS ECS/Fargate environment and using other AWS managed services. Domain Experience: Background in Fintech or Retail is highly preferred. Previous experience with POS systems, B2B marketplaces, e-commerce, and Banking/Payments integrations is a massive plus. Problem Solver: You can take a vague business requirement and turn it into a working algorithm/microservice. Language: Fluent English is mandatory. Spanish is a significant advantage for understanding the business requirements of the LATAM retail market. What To Expect Flexibility - We have standard 40-hour work weeks. While our agency working hours are from 9 am to 7 pm CET, you’ll have the freedom to work flexible hours and maintain a healthy work-life balance. Just make sure the majority of your working hours fall within that time frame. Remote work & Tooling - We operate as a fully remote team. We utilize HubStaff for time tracking and work transparency. We value trust and output, and these tools help us streamline administrative overhead. Culture - We value collaboration, openness, a willingness to learn, lead, and a curious nature. Our approach encourages mistakes as long as we are willing to learn from them, fostering a culture where growth comes from understanding and overcoming challenges. Autonomy and responsibility – You’ll be trusted to get things done efficiently and effectively. Hiring Process Application review - We’ll review your experience, background, and overall fit for the role. Video Call with HR - Initial conversation about fit, availability, and expectations Second interview with Leadership - If there is a strong match after the first conversation, we’ll invite you to a second interview with the Leadership team. This discussion will focus primarily on cultural fit, ownership, communication, and the way you approach collaboration and problem-solving. We may also revisit a few technical topics if anything needs additional clarification. Welcome to Afternow! Timeline: We're moving quickly. If you're the right fit and can start immediately, we can move through this process within 1-2 weeks. Apply Now If you have strong Java/Spring experience, and enjoy building scalable backend systems and microservices, we’d love to hear from you. Show us your work that demonstrates: Java 21, Spring Boot, and modern backend architectures Microservices, DDD, and event-driven systems AWS, Kafka, PostgreSQL, and high-performance APIs Fintech, retail, POS, e-commerce, or marketplace platforms Fast-paced environments, ownership, and practical problem-solving Your future starts today. Let’s talk. Afternow is an equal opportunity employer. We believe diverse teams build better products and create better experiences. We encourage applications from people of all backgrounds, experiences, and perspectives.