Rohan
Mahajan

Led end-to-end engineering across a production RAG pipeline, DOOH advertising network, and full-stack campaign dashboard for Walmart's in-store ad ecosystem.

• Architected a production RAG pipeline — pgvector embeddings + LangChain retrieval + natural-language analytics — reducing analyst report turnaround by 70% and eliminating manual SQL dependency.
• Expanded DOOH ad network from TV Walls to 7 channels (Self-Checkout, In-Aisle, Auto Parts, Vision Center, Electronics) — supporting $228K+ campaign budgets and 1.3M+ ad plays/month.
• Built Java Spring Boot microservices for ad scheduling & validation — decoupled ingestion pipeline, reduced p99 validation latency by 40%, enabled horizontal scaling.
• Owned the full-stack campaign dashboard: React / TypeScript frontend, Spring Boot + Node.js APIs, PostgreSQL and BigQuery data layer.
• Designed Apache Airflow ETL pipelines with Python to normalize ad data from Salesforce CRM and 7+ channel sources, replacing manual reconciliation.
• Built AI agent tooling using Anthropic / Claude API for code-generation and reporting workflow automation.

Contractor engagement → direct FTE offer from Walmart Global Tech (Feb 2023).

Delivered the Walmart Spark Driver platform — last-mile gig driver onboarding and operations. Exceptional performance earned a direct FTE offer from Walmart Global Tech India.

• Scaled Spark Driver from 6,000 to 150,000+ active drivers — directly enabling Walmart's US last-mile delivery expansion.
• Built Java Spring Boot REST APIs with circuit-breaker and service-discovery patterns to sustain 25× driver volume growth.
• Engineered a shared React / Next.js component library with 100% unit test coverage, accelerating feature velocity.
• Built Node.js / Express aggregation layer + provisioned AWS S3 and ELB for scalable, highly available deployment.

Owned full-stack development for Gartner's core B2B product website in Adobe Experience Manager, leading a modernization initiative.

• Migrated legacy server-rendered pages to React SPA components for a global enterprise audience.
• Conducted Lighthouse audits and resolved critical rendering bottlenecks, improving Core Web Vitals scores on high-traffic global site.

Built web platforms for Fortune 500 clients — Roche, Johnson Outdoors, Kia Motors — using Adobe Experience Manager.

• Delivered mobile-first full-stack platforms in HTML5, CSS3, JavaScript, SASS, Node.js, and Drupal.
• Resolved WCAG 2.0 accessibility violations across pharmaceutical and automotive client sites.

Led frontend engineering for India's national public broadcaster.

• Established the organization's first frontend standards documentation across HTML, CSS, JavaScript, and PHP.

Enterprise software engineering training.

• Built and presented a proof-of-concept on AngularJS directives as an internal knowledge-sharing initiative.