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I am a Senior Full-Stack Engineer with 10+ years designing cloud-native platforms across wealth management, payments, retail, and digital banking using Java, Kotlin, Spring Boot, React, Angular, and TypeScript. I specialize in modernizing legacy systems into modular, event-driven architectures that accelerate feature delivery, improve reliability, and support millions of daily transactions. I blend front-end engineering with scalable backend services, delivering data-rich interfaces backed by microservices, APIs, and real-time pipelines aligned to clear business outcomes. I also apply DDD, clean architecture, and Python-driven automation with emerging AI components to streamline workflows, elevate analytics, and support cross-functional teams with clear technical guidance.…I am a Senior Full-Stack Engineer with 10+ years designing cloud-native platforms across wealth management, payments, retail, and digital banking using Java, Kotlin, Spring Boot, React, Angular, and TypeScript. I specialize in modernizing legacy systems into modular, event-driven architectures that accelerate feature delivery, improve reliability, and support millions of daily transactions. I blend front-end engineering with scalable backend services, delivering data-rich interfaces backed by microservices, APIs, and real-time pipelines aligned to clear business outcomes. I also apply DDD, clean architecture, and Python-driven automation with emerging AI components to streamline workflows, elevate analytics, and support cross-functional teams with clear technical guidance.

Shahn Khan

Full Stack Developer, Web Developer, Front-End Developer, +2

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I am a Senior Full-Stack Engineer with 10+ years designing cloud-native platforms across wealth management, payments, retail, and digital banking using Java, Kotlin, Spring Boot, React, Angular, and TypeScript. I specialize in modernizing legacy systems into modular, event-driven architectures that accelerate feature delivery, improve reliability, and support millions of daily transactions. I blend front-end engineering with scalable backend services, delivering data-rich interfaces backed by microservices, APIs, and real-time pipelines aligned to clear business outcomes. I also apply DDD, clean architecture, and Python-driven automation with emerging AI components to streamline workflows, elevate analytics, and support cross-functional teams with clear technical guidance.…I am a Senior Full-Stack Engineer with 10+ years designing cloud-native platforms across wealth management, payments, retail, and digital banking using Java, Kotlin, Spring Boot, React, Angular, and TypeScript. I specialize in modernizing legacy systems into modular, event-driven architectures that accelerate feature delivery, improve reliability, and support millions of daily transactions. I blend front-end engineering with scalable backend services, delivering data-rich interfaces backed by microservices, APIs, and real-time pipelines aligned to clear business outcomes. I also apply DDD, clean architecture, and Python-driven automation with emerging AI components to streamline workflows, elevate analytics, and support cross-functional teams with clear technical guidance.

Available to hire

I am a Senior Full-Stack Engineer with 10+ years designing cloud-native platforms across wealth management, payments, retail, and digital banking using Java, Kotlin, Spring Boot, React, Angular, and TypeScript. I specialize in modernizing legacy systems into modular, event-driven architectures that accelerate feature delivery, improve reliability, and support millions of daily transactions.

I blend front-end engineering with scalable backend services, delivering data-rich interfaces backed by microservices, APIs, and real-time pipelines aligned to clear business outcomes. I also apply DDD, clean architecture, and Python-driven automation with emerging AI components to streamline workflows, elevate analytics, and support cross-functional teams with clear technical guidance.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

English

Fluent

Work Experience

Lead Full-Stack Consultant / Solution Architect (Fidelity Investments engagement) at CAI (Computer Aid Inc.)

June 1, 2022 - Present

Modernized Fidelity’s wealth-management ecosystem by transforming a 20-year COBOL monolith into Spring Boot and Kotlin-based cloud-native microservices, cutting release cycles by 35% and enabling parallel advisor feature delivery. Defined portfolio, order, and valuation domains via Domain-Driven Design workshops to strengthen boundaries and reduce cross-team data friction. Modernized advisor dashboards with React and TypeScript, improving data freshness and reducing page load times from 8s to ~2s for high-volume sessions. Implemented a unified GraphQL Gateway across REST, SOAP, and gRPC to streamline frontend data consumption. Architected an event-driven trading pipeline with Kafka, transactional outbox, and idempotent producers to ensure reliable trade execution. Delivered real-time trade confirmations through WebSockets and STOMP supporting 60K+ concurrent advisors. Built a rule-driven portfolio rebalancing engine with Spring Batch/State Machine, enabling analysts to adjust complia

Lead Full-Stack Consultant / Solution Architect (Walmart Global Tech engagement) at CAI (Computer Aid Inc.)

June 1, 2022 - Present

Led the rebuild of Walmart’s legacy checkout monolith into Spring Boot, Kotlin, and microservices coordinated by sagas and event streams, enabling consistent order, payment, and inventory workflows across global channels. Modeled core retail aggregates (Cart, LineItem, FulfillmentTask, ReturnCase) using DDD and CQRS to support high availability and stable throughput during 2M+ orders per hour on peak days. Built a domain-event choreography layer on Kafka that synchronized pricing, promotions, and inventory across 1,200 stores, ensuring sub-second accuracy for omni-channel operations. Directed front-end modernization with Angular, TypeScript, and RxJS to deliver real-time dashboards for fulfillment, SLA tracking, and order heatmaps. Designed a dynamic pricing engine with Spring Expression Language, Redis, and caching strategies that evaluated promotion rules in under 10 ms at scale. Implemented reactive inventory services using Project Reactor and WebFlux to enable instant stock updat

Senior Full Stack Engineer at PayPal Holdings Inc.

June 1, 2018 - May 31, 2022

Modernized PayPal’s merchant integration stack by decomposing a large Java EE platform into Spring Boot microservices, improving API performance by ~45% and clarifying ownership across payments, disputes, and risk teams. Built a universal checkout gateway using Spring Cloud to support PayPal, Card Vault, Venmo, and Crypto rails during peak events. Designed event-driven workflows for settlements, refunds, and reconciliation using Kafka and schema registry, reducing data inconsistencies across merchant reporting by ~70%. Led the rebuild of the merchant developer portal with React, TypeScript, and component-driven design for clearer self-service experiences. Introduced reactive programming with Project Reactor in payment authorization flows to support asynchronous risk checks under high throughput (50K+ TPS). Developed telemetry microservices in Go for real-time latency, fraud signals, and transaction metadata. Improved persistence reliability with PostgreSQL, JPA, and Redis to resolve

Software Engineer at PNC Bank

November 1, 2016 - May 31, 2018

Re-engineered legacy Struts customer-service modules into Spring Boot microservices, separating account, loan, and payment workflows to enable bi-weekly releases in a regulated banking environment. Designed secure REST APIs for account lookup, ACH transfers, and payoff quotes using Spring Security, OAuth2, and JWT. Built responsive online-banking portals with Angular/TypeScript, delivering real-time balances, e-statements, and MFA flows to boost digital adoption. Implemented asynchronous transfer notifications using Kafka and Spring Integration, ensuring reliable event propagation across fraud, ledger, and CRM systems. Normalized COBOL-era data with JPA/Hibernate to support near-real-time replication into analytics stores. Integrated PCI-DSS and SOX validation rules into API middleware, reducing manual audits. Automated regression testing with Selenium, JUnit 5, and service virtualization, cutting UAT timelines and increasing deployment confidence. Optimized Oracle PL/SQL queries and A

Full-Stack Engineer at CommerceIQ Technologies

August 1, 2014 - October 31, 2016

Co-architected the company’s first SaaS retail analytics platform using Java, Spring Boot, and AngularJS, delivering real-time visibility into sales, pricing, ads, and operations for multi-market sellers. Built a unified product-catalog ingestion framework that pulled data from retailer APIs and FTP feeds, normalizing millions of SKUs into MySQL RDS and MongoDB. Developed an automated pricing optimization engine combining competitor tracking, demand signals, and rule-based adjustments to improve client margins. Delivered a responsive analytics portal with AngularJS, Highcharts, and in-memory caching for sub-second dashboard refreshes. Implemented multi-tenant security with Spring Security and JWT. Built Python ETL pipelines with Celery and S3 to power a scalable data lake and predictive dashboards via Athena. Automated CI/CD pipelines with Jenkins and Docker to drastically reduce build-to-deploy time. Defined lightweight REST contracts and consistent JSON schemas across microservices