Sajankumar – AWS, Python, React

A full-stack multi-tenant application template with a FastAPI backend and React (TypeScript) frontend. Designed for efficient single-infrastructure deployment, it provides secure tenant isolation with a scalable, maintainable architecture and built-in support for authentication, payments, storage, and AI features.

• Designed and implemented the overall system architecture (multi-tenancy, RBAC, isolation).
• Built backend services using FastAPI with clean architecture principles.
• Developed frontend features using React and TypeScript.
• Implemented authentication (JWT, SSO, magic links, passkeys) and user management.
• Integrated third-party services (Stripe, AWS S3, Azure Blob Storage).
• Designed and implemented tenant, role, and feature management systems.
• Led the development of an AI chat interface with real-time streaming.
• Oversaw deployment strategy and infrastructure integration (e.g., domain routing, Coolify).

A software which transforms static documents like PDFs, Excel models, scanned contracts, and images into an intelligent, searchable knowledge base.

• Created front-end and back-end architecture.
• Configured RAG and Vertex embeddings.
• Built deployable chatbot.
• Implemented voice integration.
• Configured payments and subscriptions along with complete k8s infrastructure with Tailscale.
• Configured complete CI/CD via Github workflow.

A high-concurrency voice agent integrated via real-time API with Practice Management Software (Dentrix, Curve). An intent recognition layer differentiates clinical emergencies from routine bookings and routes each appropriately. The agent reads live calendar availability to confirm appointment slots inside the same call. A sentiment-detection layer monitors caller frustration and triggers an instant SMS escalation to the human receptionist when the conversation exceeds its confidence threshold.

• Successfully plugged a "revenue leak" by capturing inquiries that previously went unanswered outside of business hours leading to 40% increase in after-hours lead capture.
• Automated repetitive scheduling tasks, significantly lowering the administrative burden on receptionists which led to 15% reduction in staff burnout.
• Freed up staff to prioritize high-value, in-chair patient care rather than managing phone lines leading to enhanced clinical focus.
• Achieved continuous, 24/7 operation with zero incremental labor costs per patient interaction.

This project represents a high-scale integration of Identity Management (IAM) and Real-Time Communication (RTC) designed to power the digital future of a leading entertainment brand like RTL. At its foundation, the platform acts as a centralized ecosystem that harmonizes the user experience across diverse touchpoints, including broadcast applications, news portals, and premium streaming services. By implementing a sophisticated Single Sign-On (SSO) gateway, the system seamlessly manages millions of user profiles, ensuring that a single set of credentials provides secure, frictionless access to an entire media portfolio.

The intelligence of the platform lies in its "Gatekeeper" logic, where every connection request triggers a real-time validation sequence. Before a stream is initiated, the system synchronizes with a robust Subscription Management layer to perform entitlement mapping—determining in milliseconds whether a user possesses the "Premium" status required for specific content, such as live sports or exclusive news feeds. This data doesn't just control access; it drives deep Profile Personalization, allowing the user interface to dynamically adapt with tailored content recommendations and "Continue Watching" features based on historical profile data stored within the central hub.

• Orchestrated the end-to-end development of a centralized OIDC portal using .NET Core and React, successfully unifying the authentication experience for millions of users across the company’s broadcast and digital platforms.
• Architected a low-latency live broadcasting solution using WebRTC, reducing stream delay from 30 seconds to sub-second levels for rtl.nl. This enabled synchronized "Second Screen" interactivity and real-time audience engagement for live news and sports.
• Owned the integration of the Buckaroo payment gateway, architecting custom recurring billing logic and high-reliability webhook handlers to ensure "zero-gap" subscription management and revenue continuity.
• Spearheaded the transition from legacy MVC views to a high-performance React component library, standardizing the identity suite’s UI and reducing future feature deployment time by creating a reusable, scalable frontend architecture.
• Ensured 100% GDPR compliance and implemented rigorous security protocols for a high-scale profile management system, protecting the personal and financial data of millions of active subscribers.
• Defined and executed a comprehensive testing strategy, authoring the unit and E2E test suites that secured the critical "checkout" and "sign-in" paths, maintaining 24/7 service availability for the entertainment ecosystem.

A comprehensive, end-to-finish workflow solution designed to bridge the gap between individual 3D printing and enterprise-scale production. It is the only platform that offers a completely free entry point for slicing, printing, and monitoring, while providing a robust infrastructure for professional organizations to scale.

Core Objectives of the project were:

• Streamlining the entire additive manufacturing process—from initial slicing to the final finished part—within a single cloud interface.
• Enabling businesses to manage multiple printers and high-volume operations with professional-grade oversight.
• Integrating IT-friendly features like SSO (Single Sign-On) and Cura Enterprise to ensure data integrity and organizational standards.

• Designed and implemented the front-end and back-end architecture to support high-concurrency cloud printing, ensuring the system could scale from individual users to enterprise-level printer fleets.
• Implemented a high-performance full-text search engine, allowing users to instantly navigate through vast libraries of 3D projects, print logs, and printer configurations.
• Orchestrated integrations with diverse service providers (including cloud storage and SSO authentication) to ensure a "business-friendly" workflow and enterprise IT compliance.
• Led the complete redesign of the existing front-end, transforming a complex slicing interface into a modern, intuitive user experience.
• Built a custom, reusable front-end component library to standardize UI elements across the UltiMaker ecosystem, accelerating development cycles and ensuring visual consistency.
• Established a rigorous testing culture by writing unit, integration, and E2E tests, ensuring that the "start-to-finish" cloud solution remained stable during rapid feature rollouts.
• Actively debugged and resolved critical application issues, specifically focusing on the communication bridge between cloud slicing tools and physical printer hardware.

A global leader in advanced information and decision support for science and healthcare. By combining high-quality content with powerful analytics, they transform complexity into clarity and deliver mission-critical insights that help professionals make better decisions.

• Played a key role in modernizing legacy codebases, significantly improving the performance, scalability, and maintainability of core publishing platforms.
• Led the development of efficient, accessible frontend applications and introduced a reusable UI branding library, streamlining design consistency across multiple product teams.
• Helped define realistic coding milestones and ensured on-time delivery through transparent communication and Agile best practices.
• Contributed to high-level architectural decisions, conducted thorough code reviews, and upheld engineering standards through detailed documentation and QA processes.
• Leveraged AWS services, including EKS and ECR, to implement scalable, containerized deployments, improving infrastructure reliability and deployment efficiency.