Senior Backend Developer (Java/Spring Boot)

This a Full Remote job, the offer is available from: Europe Quick summary This is a fully remote position. Looking for people in Europe or LATAM. Professional English is a must. All company and client communication is in English. Spanish is a strong bonus. 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. Build the "Central Operating System" for Latin American convenience stores (bodegas). You will replace manual notebooks with a high-performance, AI-integrated retail engine. Salary: Gross (B2B) 3000€ ~ 4000€ / month. About us BB Agency is a partner for digital evolution, blending creativity and technology to drive meaningful growth. We collaborate with companies focused on real human needs, shaping brands, experiences, and products that impact millions daily. Founded in 2012 on Island Krk, Croatia, we've grown into a fully remote agency with a global team of 50+ members. We believe in learning by doing, open communication, and pushing boundaries to deliver our best work. Our clients range from tech SMEs to corporations and funded startups in SaaS, finance, healthcare, and more. We’ve partnered with names like AWS, Deloitte, BNP Paribas, ShipBob, Intercorp, and CloudZero, among many others. Job description 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. Your Responsibilities

• 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.

Preferred experience

• 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

• Pre-selection based on your application (We’ll review your experience, past projects, and skills).
• Introductory call with HR to get to know you better.
• Interview with our Development Team leadership.
• Welcome to BB Agency.

CompensationGross (B2B) 3000€ ~ 4000€ / month This offer from "BB Agency" has been enriched by Jobgether.com and got a 82% flex score. Apply tot his job Apply To this Job