Abhishek Shukla

Built and owned back-end services for a SaaS e-commerce platform, modeling long-running asynchronous payment and subscription lifecycles with explicit state machines, strategy patterns, and an append-only event log. Orchestrated distributed, multi-step workflows with idempotent Kafka consumers to ensure transitions remain auditable, replayable, and safe against duplicates, out-of-order, and partial failures. Integrated external services and payment gateway webhooks using idempotent handling plus retry/backoff and reconciliation so duplicates or delayed callbacks never corrupt system state. Implemented observability with OpenTelemetry and Jaeger, reduced incident diagnosis time significantly, and supported production through alerting and on-call. Shipped core microservices for cart, payments, subscriptions, billing, and vendor/consumer domains in Java with Spring Boot/WebFlux and database-per-service design, improving API latency by optimizing caching, indexing, and queries.