Sebastian Michael

Led backend modernization and API development for Yes Bank and PhonePe as a senior integration engineer. Managed a team of 6 backend engineers migrating critical RESTful APIs from IBM Integration Bus (IIB) to IBM App Connect Enterprise (ACE), ensuring production readiness and compliance with SLAs for high-volume banking services. ​ Architected custom API integrations and Oracle database configurations for PhonePe that reduced transaction latency from 1.5 seconds to under 0.5 milliseconds, enabling the platform to handle billions of daily transactions. Delivered full-cycle backend solutions including service design, database modeling, API implementation, and live environment rollout in collaboration with PhonePe's technical leadership. Implemented production-grade logging, monitoring hooks, and load testing benchmarks to ensure scalability and observability across all deployed services.

Designed and built scalable backend services for India's largest financial institution (State Bank of India), delivering core banking features including digital onboarding, payments, and third-party integrations. Developed RESTful APIs using Java and ESQL that powered mobile and web clients, including backend support for SBI's Yono Krishi agriculture gold loan platform enabling 24-hour loan approval and disbursement to farmers. Integrated backend logic with AngularJS front ends across multiple platforms and implemented CI/CD automation pipelines using Jenkins to ensure smooth deployments across development, staging, and production environments. Led backend encryption and security initiatives, embedding AES and RSA encryption to safeguard sensitive customer and financial data. ​ Collaborated with DevOps, QA, and frontend teams to test and validate backend API responses under high-load conditions, ensuring reliable performance at scale.

Engineered backend services for Yes Bank's core banking APIs using IBM Integration Bus (IIB) and WebSphere MQ, integrating PL/SQL-based data operations to support high-throughput transactional workloads. Designed and delivered a high-performance payment API for the bank's mobile platform from scratch, reducing transaction latency and enabling 24/7 RTGS capability compliant with RBI mandates. ​ Built dynamic backend orchestration logic using custom flow-triggering components to support real-time processing of payments, error handling, and service retries. Optimized backend workflows for Dream11's IMPS transaction routing with an Intelligent Automated Routing engine, improving success rates and gaining client accolades. ​ Participated in architectural design reviews and contributed to improving backend scalability, fault tolerance, and monitoring across development, staging, and production environments.

Engineered backend integrations for an enterprise ERP rollout at Nirav Modi Jewellers, linking SAP, Salesforce CRM, and POS systems via IBM Integration Bus (IIB) to ensure seamless data synchronization and operational efficiency. Designed and deployed scalable SOAP and RESTful web services supporting backend data exchange across 120+ departments at Axis Bank, enabling secure and efficient interdepartmental communication. Built resilient backend messaging patterns using record-and-replay with advanced error handling and automated retry logic, leading to a 30% reduction in transaction failures. Oversaw the final delivery phase for iPad database services used in iOS systems, managing backend provisioning, deployment pipelines, and post-launch support for production stability.