Raj kumar Mahto

Frontend Engineer with 3 years of experience building high-performance interfaces for AI-driven and data-intensive applications. Specialized in streaming/real-time UIs, performance optimization, and scalable frontend architecture, with a proven track record of owning products end-to-end, from 0→1 to production while improving reliability, user experience, and engineering velocity.

Software Development Engineer (SDE-2) at Hypergro.ai (2023-10 – Present)

• Architected a real-time AI ad-generation pipeline over streamed backend responses using a custom incremental JSON parser (brace-depth + string-aware state machine), rendering partial payloads mid-stream to hydrate 10+ live UI components and reducing ad-creation time by 70%.
• Built a browser-based non-linear video editor on Remotion with a frame-accurate multi-track timeline (custom pixels↔frames scaling, draggable playhead, clip trim/drag), domain-split Zustand state (5 stores) with snapshot-based undo/redo and autosave, live preview, and cloud export via Remotion Lambda with real-time progress polling.
• Led frontend development as the sole frontend engineer for a 0→1 multi-tenant SaaS platform, building dashboards, analytics, and a request-scoped data layer enforcing brand-level tenant isolation while integrating backend services and third-party APIs with zero frontend-driven payment failures.
• Owned the end-to-end subscription checkout experience, implementing plan selection, coupons, billing, and post-payment verification using Remix fetchers across multiple payment gateways (Razorpay, Cashfree) with idempotent retries and graceful failure recovery.
• Extended an open-source visual editor into a JSON-driven email platform with MJML→HTML rendering, multi-format export (HTML/PDF/JPEG), and navigation safeguards (route blockers + beforeunload), eliminating data loss and saving 2 months compared with building a block editor from scratch.
• Engineered serverless rendering pipelines (HTML → PPTX/PDF/image) on headless-browser infrastructure, supporting dynamic multi-slide composition and high-volume concurrent exports while improving scalability and rendering performance.

Web Developer (Intern) at Zimyo HR Software (2023-03 – 2023-06)

• Engineered configurable, rule-based UI components using React and TypeScript with dynamic form generation and state-driven rendering, supporting 500+ client organizations with zero per-client customization overhead.
• Improved frontend stability through strong input validation, error boundaries, and defensive coding practices, reducing QA regression tickets by 25% across data-heavy workflows.
• Integrated RESTful APIs with async state management for multi-step forms, validating end-to-end data flows and contributing to the successful delivery of 3 major releases within sprint timelines.

Full Stack Web Development in Web Development – Masai School (2022 – 2023)

Bachelor of Commerce in Commerce – Neelashaila Mahavidyalaya (2018 – 2021)