About the ProjectWe are looking for a Senior Java Backend Developer to join a team tasked with stabilizing and transforming a business-critical application. The current system is fragile and has many issues, so your role will involve reverse engineering, gaining a deep understanding of both the codebase and business processes, and driving modernization.This is a brownfield project – success requires strong technical expertise, architectural thinking, and the ability to navigate ambiguity while making the system robust and future-proof. Over time, you will help rethink the architecture, improve performance, refactor existing code, and define a sustainable technical foundation.ResponsibilitiesAnalyze and stabilize a fragile application with the support of a service teamReverse engineer existing components and business logic to gain a deep understanding of the systemOptimize database queries, data access, and memory management for performance and scalabilityIdentify and implement code refactoring opportunities to improve maintainabilityRethink system architecture and recommend appropriate tools, frameworks, and approachesCollaborate with business stakeholders to ensure technical solutions align with business needsWork closely with the team to establish engineering best practices and architectural principlesRequirements5+ years of experience in Java backend developmentExperience working on brownfield projectsSolid understanding of software architecture principles and system designProven ability in reverse engineering, debugging, and stabilizing fragile systemsExperience with databases, memory management, and large-scale data handlingSkills in refactoring and improving code qualityAbility to quickly learn and understand complex business processesExcellent communication skills and openness to working with international teams (US, India, PL)Nice to HaveExperience with performance-critical enterprise applicationsQuery tuning and performance optimizationKnowledge of domain-driven design or other structured architectural approachesFamiliarity with modernization strategies and enterprise integration toolsWhy Join This Project?Work on a high-impact application that is critical to business operationsOpportunity to shape and modernize the architecture, not just maintain itLong-term potential with a multi-year modernization roadmapCollaborative international environment with challenging, meaningful problems to solve