Frontend engineer building ESG/carbon-domain B2B SaaS with React and TypeScript.

I work on report, dashboard, WebView, calculation, and validation-heavy UI for enterprise products. Recently, I have focused on AI report generation UX for long-running async jobs, frontend quality improvements, migration work, and test foundations.

const daniel = {
  role: "Frontend Engineer",
  domain: "ESG / Carbon B2B SaaS",
  stack: ["React", "TypeScript", "GraphQL", "Vite"],
  focus: [
    "Report and dashboard UI",
    "Calculation and validation flows",
    "AI report generation UX",
    "Frontend quality and migration"
  ]
};

Frontend Engineer @ Livit / Tansolution
2023.04 - Present

Tansolution is a B2B SaaS product for carbon emissions management, ESG reporting, reduction simulation, and monitoring.

• Build report, dashboard, WebView, calculation, and validation UI with React/TypeScript.
• Implement MACC simulation flows for 5 carbon-reduction measures.
• Develop ESG/reduction-project report screens and PDF/Excel output flows.
• Design frontend UX for AI report generation: progress/status UI, SSE subscription, validation feedback, retry, partial regeneration, and successful-section reuse.
• Improve frontend quality through MUI v5 to v7 migration, Webpack to Vite migration, moment.js to dayjs migration, and Vitest/RTL/jsdom test setup.

• Designed UX for long-running AI report generation jobs.
• Implemented progress/status flows, SSE-based updates, validation feedback, retry, partial regeneration, and reuse of successful sections.
• Worked with async/backend integration context such as BullMQ, Redis, NestJS, Prometheus, and vLLM/Gemma-based generation.

• Implemented input, validation, calculation, and result dashboard flows for 5 reduction measures: solar power, high-efficiency inverter, eco-friendly vehicles, high-efficiency lighting, and LNG conversion.
• Connected key calculation outputs such as marginal reduction cost, total carbon reduction, total reduction cost, and NPV discount logic to frontend UI.
• Added defensive UI logic for unit conversion, missing data, and operational edge cases.

• Built frontend flows for ESG and reduction-project reports across screen, PDF, and Excel output.
• Improved consistency of number formatting, units, decimals, totals, dynamic sheet formulas, and multilingual report output.
• Worked with ExcelJS and jsPDF for report generation and export workflows.

• Improved React component stability across 300+ changes.
• Migrated MUI v5 to v7, Webpack/react-app-rewired to Vite, and moment.js to dayjs.
• Set up Vitest + React Testing Library + jsdom and wrote 30+ utility tests.

I write about frontend work from production projects, especially AI report UX, async job flows, and frontend quality improvements.

• AI report UX: Redis/BullMQ queue and SSE real-time updates
• Frontend perspective on a vLLM/Gemma-based AI report pipeline
• Introducing Vitest to a legacy frontend project

All posts: velog.io/@seunghyeond/posts