I’m a Senior Backend Engineer with 8+ years of experience building and scaling distributed systems operating at 30K+ QPS and supporting 80K+ concurrent users. I specialize in designing fault-tolerant, high-throughput systems and have led the architecture of multi-DC, real-time platforms powering critical customer experiences at scale. My work has contributed to $700M+ business impact, while improving system reliability, latency, and efficiency. I approach engineering from first principles — focusing on correctness, simplicity, and long-term scalability. --- What I’ve built: • Real-time CRM Messaging Platform : Multi-DC, fault-tolerant system delivering real-time updates (calls, chats, incidents) to 80K concurrent agents with at-least-once guarantees. • Customer Experience Platform (30K+ QPS) : Led backend architecture; modularized gateway aggregating 100+ services; improved throughput by 30%. • Transactional Communication System : Scaled to 3M+ notifications/day with 93% higher throughput and 91% lower DB load. • Bulk Processing Platform (Spark-based) : Reduced resolution time for 20K incidents from 15 minutes to 1 minute. --- How I work: • Strong focus on reliability, performance, and observability • Known for debugging complex, cross-system issues • End-to-end ownership from design to production • Deep investment in mentorship and engineering excellence • Mentored 10+ engineers and conducted 150+ interviews. --- Beyond work: I explore new technologies, contribute to open source (Apache Pulsar, Guice, MVEL), and build side projects: github.com/SantanuKar43 Outside tech: traveling, photography, cooking, chess, badminton.