Mohammed Sinan

Built a multi-tenant NestJS SaaS backend with JWT authentication, RBAC, and IDOR protection, enforcing strict tenant-level data isolation. Engineered bidirectional Google Business Profile synchronization using OAuth 2.0, field-mask merging, inbound/outbound sync, and webhooks. Developed reliable BullMQ background workers covering Google Business Profile sync, OAuth flows, billing operations, and AI workflows. Implemented a geo-grid local rank tracking system with multi-point SERP scans, historical rankings, weekly tracking, competitor scoring, and ranking-change alerts. Created an AI-powered GBP audit pipeline using preprocessing, LLM processing, JSON Schema validation, scoring and weighted analysis, and scheduled re-audits. Integrated Stripe subscription billing including checkout, signed webhooks, idempotent event handling, coupons, subscription management, and per-location plans. Owned production background jobs, Docker deployment workflows, CI/CD pipelines, and deployments to Digit

Built and architected a multi-tenant NestJS SaaS backend with JWT authentication, RBAC, and OIDC protection, enforcing strict tenant-level data isolation. Implemented bidirectional Google Business Profile synchronization via OAuth 2.0, field-masking merging, inbound/outbound sync, and webhooks for suggested profile changes. Developed BullMQ background workers for syncing, OAuth processing, billing operations, AI workflows, and asynchronous jobs. Created a geo-grid local ranking tracking system with multi-point SERP scans, historical tracking, weekly updates, competitor scoring, and ranking-change alerts. Built an AI-powered GB profile audit pipeline (preprocessing, LLM processing, JSON schema validation, scoring, weighted analysis) with scheduled re-audits. Integrated Stripe subscription billing with checkout, signed webhooks, idempotent event handling, coupons, subscription management, and per-location plans. Owned production background jobs and Docker deployment workflows, including

Developed and maintained a 30+ page production web platform fully integrated with a content management system. Re-engineered legacy frontend code and API integrations, improving overall application performance by ~24%. Implemented server-side caching and lazy loading strategies to optimize API response handling, resource utilization, and frontend performance. Optimized and minified production bundles, reducing deployment pipeline execution time to ~34 seconds. Designed and implemented a DTO layer to standardize frontend-backend data contracts. Improved frontend architecture maintainability by modernizing routing, state handling, API communication, and reusable components. Authored comprehensive technical documentation covering system architecture, API integrations, deployment workflows, and implementation details.