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Abdullah Khalid

Full-Stack TypeScript Developer

Results-driven Full-Stack TypeScript Developer specializing in building scalable SaaS, HealthTech, and FinTech platforms. Experienced in architecting microservices, designing real-time data pipelines, and developing secure, production-grade systems. Strong background in crypto arbitrage engines, WebSocket-based market data ingestion, and cloud-native infrastructure.

Dhaka, Bangladesh
khalid.code03@gmail.com
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Skills & Expertise

A comprehensive toolkit for building modern, scalable applications

Languages

TypeScript
TypeScript
JavaScript
JavaScript
PHP
PHP
Elixir
Elixir

Frontend

React
React
Next.js
Next.js
React Native
React Native
SvelteKit
SvelteKit
TanStack Query
TanStack Query
TanStack Router
Tailwind CSS
Tailwind CSS

Backend

Node.js
Node.js
Bun
Bun
Elysia.js
Elysia.js
Fastify
Fastify
NestJS
NestJS
Express.js
Express.js
Phoenix
Phoenix
REST APIs
REST APIs
WebSockets
WebSockets

Database & Data

PostgreSQL
PostgreSQL
MySQL
MySQL
MariaDB
MariaDB
SQLite
SQLite
MongoDB
MongoDB
Redis
Redis
Prisma
Prisma
Drizzle
Drizzle
TypeORM
TypeORM
Mongoose
Mongoose

DevOps & Cloud

AWS (RDS, ElastiCache, S3, EC2)
AWS (RDS, ElastiCache, S3, EC2)
Docker & Docker Compose
Docker & Docker Compose
Linux Server Operations
Linux Server Operations
CI/CD
CI/CD
Grafana
Grafana
Vercel
Vercel
Dokploy

FinTech / Blockchain

Solana Web3.js / RPC
Solana Web3.js / RPC
Jupiter DEX
Jupiter DEX
Binance API
Binance API
KuCoin API
KuCoin API
Coinbase API
Coinbase API
dYdX
Circle USDC / Arc
Ethereum / EVM
Solidity
Solidity
Foundry / Anvil

Engineering

System Design
System Design
Clean Architecture
Clean Architecture
Real-Time Systems
Real-Time Systems
Event-Driven Architecture
Event-Driven Architecture
Performance Optimization
Performance Optimization
API Security
API Security
Journey

Work History

A chronology of my professional experience, building scalable solutions across the stack.

Jan 2023 — Present

Full-Stack TypeScript Developer

Interspeed
Remote
Building complex HealthTech and FinTech systems across enterprise laboratory workflows, real-time market infrastructure, automated trading, and financial-system R&D.
Owned approximately 85% of an enterprise Laboratory Information Management System over 2.5 years, building clinical and anatomical workflows, dynamic forms, reporting, role-based access, backend APIs, and database models.
Built TypeScript-based crypto trading infrastructure integrating centralized exchanges and Solana liquidity venues, including Binance, KuCoin, Coinbase, dYdX, and Jupiter.
Developed automated trading workflows with market monitoring, configurable opportunity detection, fee-aware profitability checks, trade lifecycle persistence, and Redis-backed asynchronous execution processing.
Built real-time market-data and trading interfaces using WebSockets, Redis, React, Next.js, and charting infrastructure.
Worked on algorithmic trading R&D covering market-data ingestion, arbitrage research, execution validation, simulation workflows, and risk-aware trading architecture.
Contributed targeted frontend and API modernization to an OpenEMR-based healthcare platform while preserving workflows within a large legacy PHP and MySQL codebase.
Built and maintained production infrastructure using AWS, Docker, Linux, CI/CD, Grafana, and cloud-hosted database services.
Jan 2020 — Jan 2023

Web Designer & Web Developer

Freelance / Contract
Remote
Worked across freelance development, team-based web design, and contract ecommerce projects, progressing from web design into frontend and full-stack development.
Delivered 100+ website designs as part of a remote web design team after an initial Fiverr engagement developed into a longer-term collaboration.
Worked with several clients through Fiverr and received 5-star reviews from both clients who left public feedback.
Built responsive business websites and client-facing interfaces across a wide range of design requirements and industries.
Worked on contract ecommerce projects, building storefront, product, dashboard, and business workflow features.
Progressed from web design into frontend and full-stack development using JavaScript, React, Next.js, Node.js, and related web technologies.
Handled client requirements, revisions, integrations, deployment, maintenance, and production troubleshooting across freelance and contract work.

Featured Projects

A selection of projects that showcase my skills and experience

FinTech / BlockchainActive R&DAlgorithmic TradingMarket IntelligenceFinTech

Algorithmic Crypto Trading Platform

R&D platform for algorithmic crypto trading infrastructure, real-time market intelligence, arbitrage research, strategy validation, and automated execution architecture.

Created an experimentation platform for evaluating trading strategies and execution workflows using real-time data, simulation, and cost-aware opportunity validation.

TypeScript•React•TanStack Query•Bun•+8 more
FinTech / BlockchainActive R&DProduct DevelopmentCircle USDC / ArcFinTech

PayBridge

Institutional cross-border settlement orchestration platform exploring how regulated payment providers can use stablecoin infrastructure for treasury settlement, liquidity management, payout coordination, and reconciliation.

Explores how stablecoin infrastructure can improve institutional cross-border settlement while keeping blockchain complexity invisible to end customers.

TypeScript•Circle USDC / Arc
HealthTechPrivate Enterprise ProjectAdvanced DevelopmentPaused After Funding EndedHealthTech

Laboratory Information Management System (LIMS)

Enterprise LIMS for hospitals and diagnostic centers, supporting clinical and anatomical laboratory workflows with strict access control and automation.

Built a feature-rich enterprise healthcare platform covering complex laboratory workflows before development paused after funding ended.

TypeScript•Next.js•Fastify•MariaDB
EcommerceProduction UsedReal SalesRelaunch PlannedPayments

Ecommerce Applications

Production ecommerce applications built for client and business-owned retail workflows, including systems used to generate real sales.

Delivered commerce systems used for real customer purchases and business operations.

TypeScript•Next.js
FinTech / BlockchainActive DevelopmentAutomated TradingCEX / DEXFinTech

Multi-Exchange Solana Trading Platform

Automated crypto trading platform for monitoring and executing Solana trading workflows across centralized and decentralized exchanges.

Unified multiple exchange and liquidity integrations behind a TypeScript trading system capable of monitoring opportunities and coordinating automated buy/sell workflows.

TypeScript•React•Next.js•Bun•+11 more
HealthTechOpenEMR ForkCustomizationPausedOpen Source

Electronic Medical Record (EMR)

Customization and modernization work on a fork of OpenEMR, improving selected clinician and patient workflows with new UI and APIs.

Improved selected workflows in a mature healthcare codebase while learning legacy modernization constraints.

TypeScript•PHP•React•REST APIs•+1 more
SaaS / PlatformsProduction UsedLive AppsJobTechProduction

Job Posting Platforms

Production job posting applications built for real business recruitment workflows, including public listings, administration, and deployment.

Delivered commercially used applications with complete frontend, backend, administrative, and deployment workflows.

TypeScript•Next.js

Services

What I can help you build

Web Development

Building responsive, performant web applications using modern frameworks like React, Next.js, and Vue.js.

  • ✓Single Page Applications
  • ✓Progressive Web Apps
  • ✓Server-Side Rendering

Mobile Development

Creating cross-platform mobile applications with React Native and Flutter for iOS and Android.

  • ✓Cross-Platform Apps
  • ✓Native Performance
  • ✓Push Notifications

Backend Development

Designing and implementing scalable backend systems with Node.js, Express, and modern databases.

  • ✓RESTful APIs
  • ✓GraphQL
  • ✓Microservices

Cloud Solutions

Deploying and managing applications on cloud platforms like AWS, Google Cloud, and Azure.

  • ✓CI/CD Pipelines
  • ✓Auto Scaling
  • ✓Monitoring

UI/UX Design

Crafting beautiful, intuitive user interfaces with attention to detail and user experience.

  • ✓Responsive Design
  • ✓Design Systems
  • ✓Prototyping

Performance Optimization

Analyzing and optimizing application performance for faster load times and better user experience.

  • ✓Code Splitting
  • ✓Lazy Loading
  • ✓SEO Optimization