We are seeking an exceptionally skilled and driven Senior Java Backend Developer to anchor the core platform. This role is critical to architecting and delivering a hyper-scalable, low-latency, and distributed system capable of supporting millions of concurrent users and high-velocity data flow. You will take extreme ownership of mission-critical services, aiming to set a new standard. This platform must be designed for cloud-agnostic deployment from day one.

Key Responsibilities :

- Architecture & Design : Design, develop, and maintain high-performance, resilient, and fault-tolerant backend services and APIs using Java and Spring Boot/Quarkus.

- Microservices Implementation : Drive the decomposition and development of services within a microservices architecture, focusing on clear contract definition, service mesh integration, and inter-service communication patterns (e.g., gRPC, REST).

- Real-Time & Low Latency : Implement and optimize real-time, bi-directional communication channels (e.g., WebSockets, MQTT) for instantaneous data synchronization and persistent connection management for millions of mobile clients.

- Database & Data Flow : Design and optimize data models and persistence layers, integrating with high-volume, low-latency databases like Cassandra, ScyllaDB, or Aerospike for primary data storage, and ensuring efficient caching and read/write performance.

- Scalability & Resilience : Implement advanced techniques for horizontal scaling, distributed transactions, circuit breakers, and load balancing to ensure 99.99% uptime and operational resilience.

- Ability to perform Research / POCs & choose the suitable technology.

Required Technical Expertise (4-5 Years Experience Focus) :

- Core Java & Frameworks : 4-5 years of hands-on experience in Java, with deep, production-grade expertise in Spring Boot (or equivalent, e.g., Quarkus/Micronaut) for building RESTful and event-driven services.

- Distributed Systems : Proven experience designing and implementing scalable services within a distributed system/microservices architecture, including experience with service discovery and configuration management.

- Concurrency & Performance : Mastery of Java concurrency primitives and advanced performance tuning (JVM optimization, garbage collection tuning, thread pool management) to achieve sub-100ms P95 latency.

- Messaging & Eventing : Expert knowledge of and hands-on experience with high-throughput message brokers like Apache Kafka or RabbitMQ for handling high-velocity data, notifications, and background processing.

- Database Expertise : Deep practical experience with at least one NoSQL distributed database (e.g., Cassandra, ScyllaDB, or Aerospike) and strong SQL proficiency (e.g., MySQL, Postgres), including complex query optimization and schema evolution.

- Testing & Quality : Proven ability to write high-quality, well-tested code, utilizing frameworks like JUnit, Mockito, and focusing on unit, integration, and performance testing.

Scalability & Performance Expectations :

- User Volume : Successfully design and scale the application backend to handle millions of concurrent, persistent mobile connections.

- Latency Goal : Services must be tuned for P95 latency of less than 100 milliseconds for critical operations like data sync and status updates.

- Cloud-Agnostic Design : Demonstrate experience designing applications for a truly cloud-agnostic environment, utilizing containerization (Docker, Kubernetes) and abstracting infrastructure dependencies to allow seamless migration between AWS, GCP, or Azure.

- Monitoring & Observability : Strong experience implementing and utilizing a robust observability stack (e.g., Prometheus/Grafana, ELK/Loki, distributed tracing like Jaeger/Zipkin) to profile performance and rapidly diagnose production issues.

Startup Mindset & Delivery Goals :

- Extreme Ownership : Ability to own a feature end-to-end, from architectural design and coding to deployment and post-launch monitoring, taking full responsibility for its success and reliability.

- Collaboration & Iteration : Thrive in a fast-paced, iterative environment, collaborating closely with mobile developers, product managers, and cloud engineers.

- Impact Focus : A strong bias for action, prioritizing work that directly impacts product