Eslam Tahoon

Architected, built, and launched ClinicR, a multi-tenant healthcare operations platform supporting 60 active organizations and 1,500+ active users, serving as the sole engineering owner for delivery and production operations. Designed recoverable workflows across appointments, services, inventory, patient balances, finance, and doctor fees, including a bulk reconciliation approach. Built granular tenant authorization and a dry-run migration framework with financial and relational verification for 20+ clinic migrations; owned roadmap, onboarding, and production support. Led technical foundation for Rassa, a B2B fashion marketplace with NestJS APIs and asynchronous processing, delivering beta to ~20 participants and ~2,000 products, including multi-supplier checkout, inventory, order, payment, commission, payout, refunds, and disputes using idempotency, retries, and recovery. Independently built and deployed Collections Agent for multimodal fashion intelligence with indexing, deduplicati

Helped evolve an early AI prototype into a commercial AI game-asset platform launched to production for game studios during a six-month fixed-term engagement. Owned major implementation of the AWS control plane using CDK, Amplify, Cognito, Lambda, DynamoDB, SQS, S3, and CloudWatch, and connected it to Python GPU workloads on Modal for productionized ComfyUI and Stable Diffusion workflows. Designed idempotent failed-job compensation using S3 events, Lambda, pending-state validation, and DynamoDB conditional updates to prevent duplicate credit refunds, and added production logging, alarms, and dashboards.

Owned key parts of a global issuer-processing platform supporting card programs across 60+ countries. Selected and implemented a microfrontend architecture using React/TypeScript with Vite and Module Federation, building the host shell and User Management as independently buildable and deployable apps. Owned User Management integration using Auth0 as the source of truth for organizations, users, roles, and permissions, backed by a GraphQL BFF for privileged operations and gateway-enforced authorization on every request. Modernized PayControl UIs from jQuery/JavaScript to React/TypeScript with shared Ant Design wrappers, standardized data-fetching hooks, Zustand patterns, and testing practices across a modernization nearing completion. Introduced Cypress E2E testing against containerized services and test databases, parallelized in CI, and made it a pull-request gate; reduced pipeline time and improved card-search performance by preventing unbounded wildcard behavior. Improved security