Senior Software Engineer in Bengaluru at bukuwarung

At BukuWarung, we are building the digital nervous system for millions of underserved merchants. As an Sr Software Engineer in Retail Engineering, you will own the high-concurrency engine powering our merchant ecosystem—from QRIS payments and order management to real-time inventory and settlements. You won’t just build features; you’ll build the reactive, non-blocking infrastructure that small businesses depend on to survive in a high-volume, reliability-sensitive environment.

We are entering a critical phase of growth where architectural depth is paramount. You will work within a Hexagonal Architecture to ensure our retail platform remains resilient and maintainable as we scale 10x and 100x. We are looking for engineers who care about clean abstractions and reducing the blast radius of failures.

• Ship at Scale: Design and deploy core features across the retail domain, including orders, inventory, settlements, vouchers, and QRIS.

• Reactive Engineering: Build and maintain high-performance, non-blocking APIs using Spring WebFlux and Project Reactor, with support for Server-Sent Events for real-time streaming to clients.

• Real-Time Streaming : Design and implement Server-Sent Events endpoints using SseEmitter / Flux to push live order status updates, inventory changes, and payment confirmations to merchant-facing UIs without polling.

• Integration & IoT: Connect our platform with internal and external services, including payments, logistics, AWS Lambda, S3, and IoT devices like our Retail Soundboxes; bridge event streams from Kafka topics to SSE channels for downstream client delivery.

• Data Mastery: Own database schema design and handle seamless migrations using Flyway and PostgreSQL.

• System Reliability: Drive improvements in distributed locking (Redis/Redisson), error handling, and scheduled job reliability.

• Quality & Mentorship: Write clean, testable code and elevate the engineering bar through rigorous code and design reviews.

What We’re Looking For

• Experience: 4–6 years of backend engineering, specifically building distributed systems.

• Java Mastery: Deep proficiency in Java 21 and modern Spring Boot (3.3).

• Reactive Mindset: Hands-on experience with WebFlux or RxJava; practical exposure to Server-Sent Events (SSE) streaming patterns is a strong plus; familiarity with R2DBC is also a significant plus.

• Architecture: Strong intuition for Hexagonal/Clean Architecture and event-driven patterns using Kafka.

• Cloud & Infrastructure: Comfortable operating within AWS (S3, Lambda, Secrets Manager) and containerized environments (Docker).