LE KHANH
Middle Frontend / Full-stack Developer
Professional Summary
Highly driven Full-stack Developer with 4+ years of experience building high-performance web platforms, scalable backend systems, and production-ready blockchain integrations. Known for architecting complex systems that handle millions of requests per second, delivering pixel-accurate interfaces, and solving concurrency problems under extreme traffic.
Specializes in modern TypeScript ecosystems, Next.js/SolidJS, Bun.js, and secure API infrastructures, with proven ability to ship end-to-end features—from UX and state management to distributed services, cryptographic workflows, and smart-contract interaction.
Combines strong system thinking with fast problem-solving: able to read blockchain protocols (Cosmos SDK, EVM), optimize databases, design robust queueing/payment pipelines, and deploy applications across Cloudflare, Kubernetes, and Nginx with CI/CD automation. Passionate about reliability, performance, and building products that scale.
Education
University of Information Technology (UIT) – Vietnam National University
Master of Information Systems
In Progress, Expected graduation: 2026
University of Information Technology (UIT) – Vietnam National University
Bachelor of Information Systems
GPA: 8.22 / 10
Academic Achievements & Research:
- Published 2 peer-reviewed scientific papers in international conferences:
- Using Blockchain and Artificial Intelligence to Build a Job Recommendation System for Students in Information Technology – RIVF 2022
https://ieeexplore.ieee.org/abstract/document/10013916 - Evaluate the Efficiency of Hybrid Model Based on CNN–LSTM in Information Technology Job Graph Network – FDSE 2023
https://link.springer.com/book/10.1007/978-981-99-8296-7
- Using Blockchain and Artificial Intelligence to Build a Job Recommendation System for Students in Information Technology – RIVF 2022
- Eureka Scientific Research Competition — Semi-finalist
- Built the official department landing site using Nuxt.js: https://ftisu.vn
Professional Experience
Full-stack & Blockchain Developer
Cavies Lab
Feb 2024 – Oct 2025
Remote
Key Project: Sei Blockchain Explorer (Seitrace) — https://seitrace.com
Lead full-stack engineer responsible for architecting, building, and scaling Seitrace, the official block explorer for Sei Network, supporting both EVM and Cosmos environments. Built the platform from the ground up with a strong focus on performance, security, and developer experience.
Lead full-stack engineer responsible for architecting, building, and scaling Seitrace, the official block explorer for Sei Network, supporting both EVM and Cosmos environments. Built the platform from the ground up with a strong focus on performance, security, and developer experience.
Platform Architecture & Performance:
- Designed and developed the entire Seitrace web platform from scratch using Next.js, Bun.js, React 19, Wagmi, Viem, and a fully custom UI component system.
- Engineered high-performance UI components with advanced techniques (Proxy patterns, event delegation, dynamic rendering, caching).
- Achieved 3 million requests/second throughput under load-testing with zero latency degradation.
- Migrated the whole platform from Node.js → Bun.js to significantly improve server performance and startup times.
- Customized Webpack/Rspack modules for automated file-path injection, enabling full automation testing.
Frontend Engineering:
- Built >100 custom reusable UI components with clean code, strict typing, and full cross-platform responsiveness (mobile & desktop).
- Implemented per-page SEO optimization compliant with Google Search Console guidelines.
- Wrote extensive Playwright component tests and unit tests for complex data-processing functions.
- Customized react-chartjs-2, implemented interactive blockchain charts, price trends, NFT metrics.
- Delivered pixel-perfect UI from Figma with high accuracy and performance.
Backend Engineering & Indexing:
- Built backend services using NestJS, GraphQL, Hasura, Redis, TypeORM, Drizzle.
- Implemented scalable blockchain indexing pipelines, optimized Postgres queries, and background workers.
- Integrated automatic NFT & token pricing via multi-source aggregation (oracles, APIs, market feeds).
- Implemented authentication, role-based access control, and asset-license management for Seitrace Logo system.
Blockchain Development:
- Wrote and customized Solidity ERC-20 / ERC-721 contracts for internal tools and partner integrations.
- Built advanced wallet-interaction tools: signing, transaction builder, token/NFT reader, marketplace utilities.
- Implemented large-scale Airdrop systems for millions of users using OpenZeppelin Merkle Tree, advanced cryptography, and WASM-based anti-bot algorithms to detect abnormal claim patterns.
- Able to read and understand Cosmos SDK modules to support Sei-specific transaction parsing and features.
AI & MCP Integration:
- Built an AI-powered chatbot using ai-sdk, integrating OpenAI & Gemini models.
- Developed a full MCP (Model Context Protocol) server, enabling partners to interact with Seitrace APIs through AI tools.
Security & DevOps:
- Experienced with Cloudflare security stack: DNS, Workers, Argo Tunnel, Turnstile, bot protection patterns.
- Configured Nginx for load balancing, reverse proxy, and gateway for multi-service server infrastructure.
- Implemented Sentry monitoring for FE/BE error tracking and performance analytics.
- Managed CI/CD pipelines with Docker, GitHub Actions, Caddy, and multi-environment deployments.
- Strong proficiency in Linux environments and command-line tooling.
React 19Next.jsBun.jsZodZustandWagmiViemTanStack QueryNestJSGraphQLHasuraRedisPostgresDrizzleSolidityCosmos SDKDockerCloudflarePlaywrightAI SDK
Full-stack Developer
Mayfest (Freelance)
May 2025 – Aug 2025
Remote
Project: High-traffic Event Ticketing Platform
- Engineered a high-concurrency ticketing platform capable of handling tens of thousands of simultaneous users, ensuring system stability during peak sale windows.
- Eliminated double-booking and race conditions by designing a seat-locking + transactional reservation mechanism that protects against overlapping purchases when multiple users select the same seat.
- Implemented a dynamic queueing system that activates during heavy traffic, enabling fair, ordered access and preventing server overload under extreme peak demand.
- Reduced payment failure rates by ~40% through robust integration with VNPay and Xendit, including retry logic, idempotent payment handlers, and reconciliation workflows.
- Developed secure event check-in flow using digitally signed QR codes with cryptographic verification to prevent forgery, duplication, and unauthorized entry.
- Built asynchronous order & payment pipelines using RabbitMQ, enabling parallel queue processing, scalable payment handling, and fast order confirmation.
- Automated PDF ticket generation with brand-consistent templates and email dispatch for purchase receipts, group orders, and event reminders.
- Improved backend throughput by 3× by optimizing NestJS services, database indexes, and Drizzle-based query paths for real-time seat availability.
- Enhanced platform reliability through Sentry monitoring, structured logging, failure-alert systems, and graceful degradation strategies.
- Delivered responsive, mobile-first UI using Next.js and modern React patterns, ensuring seamless user experience from seat selection to checkout.
Next.jsReact 19NestJSPostgresDrizzle ORMRabbitMQVNPayXenditSentryDocker
Full-stack Developer
Nhà Hàng Hoà Tuyến (Freelance)
Sept 2025 – Oct 2025
- Built marketing landing page for restaurant brand using Next.js.
- Site: https://nhahanghoatuyen.com
Next.js
Full-stack Developer
Buymed
Aug 2023 – Jan 2024
Ho Chi Minh City
Project: CSM System for Pharmacy Network Operations — https://thuocsi.com
- Architected and implemented a full CSM (Customer/Clinic/Store Management) system managing the operational workflow of a nationwide pharmacy network, covering procurement, warehousing, transportation, and retail sale processes.
- Designed the end-to-end pharmaceutical order lifecycle, enabling seamless processing from: (1) Creating drug intake documents → (2) Approval flow with signatures & validations → (3) Import request verification → (4) Warehouse receiving & internal movement → (5) Inter-warehouse transportation → (6) Delivery to pharmacy → (7) Final confirmation & audit logging.
- Reduced approval time by ~35% by building digital workflows with role-based access control, hierarchical authorization, and digital signatures for critical documents.
- Implemented scheduling & automated reminders, ensuring teams never missed warehouse deadlines, transport windows, or approval cycles, improving operational compliance across departments.
- Built robust tracking modules for: Order progress & shipment stages, Department responsibilities & handover checkpoints, Historical document storage, retrieval, and timestamped activity logs.
- Enhanced UI performance by 40% using SolidJS’s fine-grained reactivity model, reducing bundle size and improving rendering speed for large datasets and multi-step forms.
- Developed shared UI components and internal tooling that were later adopted across multiple internal Buymed platforms, increasing development speed for other teams.
- Collaborated with DevOps team to deploy Golang microservices to Kubernetes, ensuring zero-downtime rollouts, improved scalability, and better observability across environments.
- Optimized backend throughput by designing efficient Golang service handlers and MongoDB query strategies for high-volume pharmaceutical order data.
SolidJSNext.jsGolangKubernetesMongoDBDockerRBACDigital Signature Workflows
Full-stack Developer
Otoman (Freelance)
Jan 2022 – Jul 2024
- Built a cross-platform mobile app using React Native and Node.js, handling both frontend UI and backend APIs.
- Integrated payment flows and user management modules.
- Built website using Nuxt.
- Site: https://otoman.net
React NativeNode.jsNuxt
Technical Skills
Frontend (Expert)
Next.jsSolidJSReactTypeScriptBun.jsRspackTailwindCSSChakraUIUI librariesSSR/ISRSEO
Backend (Mid-level)
NestJSNode.jsGolangREST APIsmicroservicesperformance optimization
Blockchain (Junior–Mid)
Solidity (ERC-20/721)OpenZeppelinCosmos SDK fundamentalsWallet integrations (Wagmi, Viem, Reown/AppKit)
Database (Junior)
PostgreSQLMongoDBRedisTypeORMDrizzleIndexingquery optimizationInsert, copy, processing, manage billions row of data
DevOps & Infra
NginxCaddyCloudflare Worker/Tunnel/DNSGitHub Actions CI/CDDockerKubernetes (basic)
Languages
EnglishGood working proficiency
VietnameseNative