Hasan Nayem, Developer in Dhaka, Dhaka Division, Bangladesh
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Hasan Nayem

Verified Expert  in Engineering

Full-stack Developer

Dhaka, Dhaka Division, Bangladesh

Toptal member since October 26, 2021

Bio

Hasan is a senior software engineer dedicated to creating high-performance, scalable solutions that improve user experience and drive business success. With 7+ years of experience in JavaScript, TypeScript, DevOps, and cloud technologies, he excels at transforming complex problems into streamlined systems, delivering impactful solutions that meet both technical and business needs. Whether leading teams or coding hands-on, Hasan’s passion for innovation and results shines through.

Portfolio

Stack Learner
Java, JavaScript, Python, C, Data Structures, Algorithms, Design Patterns...
Toptal
Agile Development, Jira, Confluence, Google Sheets Development...
Tolobi
TypeScript 3, React.js, Next.js, Redux, React DnD, React.js, Axios...

Experience

Availability

Full-time

Preferred Environment

MacOS, Visual Studio Code (VS Code), Slack, Jira, Notion, Fedora, Zoom, GitHub, Firebase, Amazon Web Services (AWS)

The most amazing...

...application I've built is ScreenerView, an all-in-one tool using the MERN stack that streamlined the interview process and automated key tasks.

Work Experience

Founder & CEO | Technical Lead & Content Creator

2017 - PRESENT
Stack Learner
  • Led the development of a comprehensive edtech platform, ensuring scalability to support millions of learners and enabling both recorded courses and live sessions.
  • Spearheaded the system’s architecture, designed the database, and handled back-end development to ensure the platform’s smooth and efficient operation.
  • Introduced real-time BI tools to streamline decision-making, automating data ingestion and providing valuable insights.
  • Reduced development cycles under his leadership by improving project management and team collaboration while maintaining high code quality standards.
  • Balanced technical innovation with practical solutions, creating a platform that not only scales but also enriches the learning experience for thousands of students.
  • Reached a 250,000+ audience milestone on YouTube, Facebook, and learning management systems, teaching people about modern development technologies.
Technologies: Java, JavaScript, Python, C, Data Structures, Algorithms, Design Patterns, Web Development, React.js, Node.js, MongoDB, PostgreSQL, AWS, Java, JavaScript, Python, MERN Stack, Express.js, Front-end, API, Web Development, WordPress Development, APIs, Strapi, Firebase, Firestore, Supabase, Supabase Auth, Content Writing, Leadership, Security, Team Leadership, Technical Leadership, ClickUp, Slack Development, Discord, Discord.js, jQuery, Blogging, Core Web Vitals, Full-stack, Full-stack, MailChimp Development, Mailchimp API, Resend, React DnD, React Helmet, React Apollo, React.js, TypeScript, TypeORM, Mongoose, MongoDB, Planning, Design Strategy, Stripe Development, Stripe Development, Website Optimization, Page Speed Optimization, WordPress REST API, API Integration, Accessibility Development, Web Accessibility, Agile Development, Ajax, Axios, Autocomplete, Full-text Search, Google Calendar API, YouTube API, Automation, Back-end Developers, Back-end Developers, Back-end Developers, Back-end Developers, Back-end as a Service (BaaS), Back-end APIs, Mobile Back-end, Architecture, System Design, Design Systems, Best Practices, CSS, CSS3, CSS, HTML, HTML5, ChatGPT, OpenAI, OpenAI API, OpenAI SDK, OpenAI GPT-3 API, GPT-4, Checkout, Cloudflare, Amazon CloudFront, AWS, Communication Coaching, Content Management Systems (CMS), Content Marketing Platforms, Cron, Customer Portals, Kinde, Auth, Auth0, System Security, Authentication, Role-based Access Control (RBAC), Dashboard, Web Dashboards, Data, Data Analysis, Data Science, Metabase, Tableau Development, Airbyte, Apache Kafka, Apache, Bootstrap, Bootstrap 5, Material UI, Ant Design, Data Integration, Scraping, Puppeteer, Cypress, Data Scraping, Website Data Scraping, Linode, Deployment, Git, GitHub, Git, Git, API, GitHub Actions, GitHub Pages, Fastify, Hono, tRPC, GraphQL, REST, API Management, Swagger, API, Microservices Development, RESTful Microservices, Microservices Architecture, Event-driven Design (EDD), Next.js, NextAuth.js, Zustand, Zod, Yup, Joi, SQL, SQL, Database, Database Design, Database Schema Design, Redis, Redis Cache, Redis Queue, Redis Pub/Sub, ESLint, Prettier, Visual Studio Development, Amazon S3, AWS RDS, Amazon EC2, Amazon EKS, ECS, Amazon Virtual Private Cloud (VPC), Amazon Route 53, AWS Lambda, AWS, Vimeo Development, Vimeo API, YouTube Marketing, JSON, CSV, CSV File Processing, Google Analytics 4 (GA4), Google Analytics, Google Analytics, REST API, JSON REST APIs, Email, React Email, EmailJS, PDF, PDF.js, SMS Gateways, Email Automation, Payment Gateways, Task Scheduling, Apache Airflow, SMTP, FTP, SSH, Database, Software Development Lifecycle (SDLC), Software Requirements Specifications (SRS), Agile Software Testing, QA Testing, Software Architecture, Web Development, Server-side Rendering (SSR), TypeScript 3, TypeScript 5, Zoom Development, Winston, Web Development, Web UI Design, UI Design

Senior Software Engineer

2022 - 2024
Toptal
  • Took the lead on building ScreenerView, a user-friendly tool that made the interview process smoother by integrating data from various sources, making life easier for screeners.
  • Developed the back end for the Talent Persona app, helping the sales team better match candidates with clients, ultimately improving the hiring experience.
  • Created the Screening Calculator, a sophisticated system that automated the candidate assessment process, making evaluations more consistent and accurate.
  • Overcame technical challenges by designing a Chrome extension to pull candidate data seamlessly, even without API access.
  • Automated repetitive tasks with custom scripts, significantly streamlining operations and freeing up valuable time for the team.
  • Balanced technical complexity with user needs consistently, ensuring solutions were not only efficient but also easy to use for the team.
Technologies: Agile Development, Jira, Confluence, Google Sheets Development, Google Docs Development, Google Slides, Figma, HTML5, CSS3, CSS, JavaScript, JavaScript, TypeScript, React.js, React DnD, React.js, React Hooks, React Hook Form, React Helmet, Next.js, NextAuth.js, Node.js, Express.js, Axios, Moment.js, JSON Web Tokens (JWT), Ajax, Algorithms, Data Structures, Database, Lodash, Zustand, Redux, React.js, Formik, Prettier, ESLint, ECMAScript (ES6), Babel, Webpack, Storybook, Vite, Zod, Yup, Joi, Chrome Extension Development, Prisma, Bcrypt, CORS, CRUD, Socket.IO, Cron, JSON, Swagger, Winston, Dotenv, REST, GraphQL, HTTP, HTTP2, Jest, Auth0, OAuth, System Security, Role-based Access Control (RBAC), PostgreSQL, MongoDB, Resend, React Email, Redis, Redis Cache, Redis Pub/Sub, Redis Queue, Cloud Engineering, Cloud Run, Google Cloud SQL, Google Cloud Build, Cloud Storage, Docker, Docker Hub, Git, GitHub, API, GitHub Actions, GitHub Workflows, Git, GitLab CI/CD, Database Migration, Ruby, Ruby on Rails, RabbitMQ, CSV, CSV File Processing, Unit Testing, Integration Testing, Time Management, Empathy, Communication Coaching, Database Design, Database Schema Design, Relational Database Design, System Design, Software Requirements Specifications (SRS), Microservices Development, RESTful Microservices, Front-end, API, Web Development, Design Systems, Picasso, OpenAI, OpenAI API, OpenAI GPT-3 API, GPT-4, OpenAI Assistants API, OpenAI SDK, ChatGPT, Software Development Lifecycle (SDLC), Agile Software Testing, Software Architecture, Visual Studio Development, Web Development, Server-side Rendering (SSR), TypeScript 3, TypeScript 5, Zoom Development, Web Development, Web UI Design, UI Design

Full-stack Developer

2021 - 2021
Tolobi
  • Completed this project-based job and maintained it for a few months.
  • Built and managed front-end and back-end applications as the sole developer.
  • Implemented a complex filtering system to find the nearest lease using Google Maps and Prisma.
  • Built many complex forms using Formik and validated forms using Yup.
Technologies: TypeScript 3, React.js, Next.js, Redux, React DnD, React.js, Axios, React Apollo, Styled-components, Antd, Prisma, PostgreSQL, Node.js, Express.js, GraphQL, Heroku, Netlify, Intercom, Stripe Development, Stripe Development, Google Maps Development, Google Maps Development, Formik, Yup, TypeScript, Full-stack, Front-end, Back-end Developers, Software Development Lifecycle (SDLC), Data Structures, Algorithms, JavaScript, Git, GitHub, Visual Studio Development, Web Development, Server-side Rendering (SSR), TypeScript 5, Winston, Web Development, Web Development, Web UI Design, UI Design, System Security

Senior Full-stack Developer

2021 - 2021
Gemstone Lights
  • Redeveloped an existing WooCommerce store from scratch using Node.js and React on top of AWS.
  • Solved hundreds of critical business problems to shape all unique requirements in a single dashboard.
  • Created and managed multiple microservices on AWS.
  • Developed multiple complex front-end applications using React, Next.js, and Redux.
  • Grew the team from zero to ten members, including a back-end engineer, DevOps, and a mobile application developer.
  • Followed the Scrum framework and used Jira as a project management tool and Slack for communication.
  • Managed the team using Agile methodologies with daily standups, weekly sprints, and Kanban boards and issue trackers.
Technologies: JavaScript, TypeScript 3, HTML5, SCSS, Git, GitHub, SourceTree, React.js, Next.js, Redux, React.js, React DnD, Formik, Node.js, Express.js, MongoDB, MySQL, Redis, AWS, Amazon API, AWS Lambda, Amazon EC2, Serverless Framework, AWS, AWS, AWS, AWS, AWS, Amazon S3, CircleCI, Docker, Amazon Cognito, AWS Amplify, JavaScript, TypeScript, AWS, Microservices Development, Dashboard, Scrum Master Consulting, Jira, Slack Development, Agile Development, Kanban Project Management, WooCommerce Design, E-commerce marketing, Full-stack, Front-end, Back-end Developers, Software Development Lifecycle (SDLC), Software Requirements Specifications (SRS), Agile Software Testing, Algorithms, Visual Studio Development, Web Development, TypeScript 5, WordPress REST API, Winston, Web Development, Web Development, Web UI Design, UI Design, System Security

Stack Learner Core Edtech Solution

PROBLEM STATEMENT
Stack Learner needed a scalable platform to deliver recorded courses, live workshops, and project-based learning and manage business operations through an integrated ERP system.

SOLUTION AND CONTRIBUTIONS
• Led the architecture and development of the Stack Learner Core Application, a comprehensive ed-tech platform built using TypeScript, Node.js, PostgreSQL, and Redis.
• Developed a project-based learning system, quiz engine, and ERP tools for seamless business management.
• Ensured scalability to support millions of learners and created a robust backend infrastructure to manage courses, student profiles, and real-time interactions.

ScreenerView Application

PROBLEM STATEMENT
There was an opportunity to enhance the interview experience at Toptal by streamlining the screening process, reducing tool-switching, and improving consistency in candidate evaluations.

SOLUTION AND CONTRIBUTIONS
• Developed ScreenerView using the MERN stack, centralizing interview preparation, execution, and evaluation.
• Created a Chrome extension to collect candidate data without API access.
• Automated repetitive tasks, reducing manual effort and saving significant time.
• Built a modular system for flexible interview setups.
• Utilized PostgreSQL and MongoDB for efficient data storage and retrieval.
• Enhanced the overall process, improving consistency and reducing screening time.

Talent Persona Generator

PROBLEM STATEMENT
The Toptal sales team needed an efficient way to generate talent personas from client inputs to streamline the talent-matching process.

SOLUTION AND CONTRIBUTIONS
• Developed the back end for the Talent Persona application using TypeScript, REST API, and OpenAI, enabling the automated generation of talent personas based on client questions.
• Integrated client input analysis to create more refined and accurate candidate personas, improving the matching process.
• Streamlined the sales workflow by connecting personas directly to the talent database for faster candidate selection.

Screening Calculator

Toptal screeners needed a way to standardize candidate evaluations, as task variations and grading complexity often led to inconsistent results.

SOLUTION AND CONTRIBUTIONS
• Developed the screening calculator using the MERN stack, automating the evaluation of tasks based on dynamic requirements and weights.
• Built a system that allows managers to create task variations and generate shareable links with timers for screeners.
• Automated the scoring process, reducing human error and improving evaluation consistency.
• Designed a user-friendly interface that streamlined task grading, adapting to different interview needs.

Chat Filtering Application

A chat filtering application for my client that used Twilio to serve its clients.

REQUIREMENTS
• Read and process chat history from the Twilio API.
• Filter, tag, and assign chat sessions to an admin based on the record.
• Send an email addressed to the admin for some particular keywords.

SOLUTION
• Developed the back end using Strapi and the front end with Next.js.
• Customized every aspect of the Strapi CMS to make it work.
• Produced several graphs based on chat activity.

Tolobi | A Property Rental Service

https://tolobi.com/
PROBLEM STATEMENT
Tolobi, a property rental service in Canada, needed a platform to help users easily locate nearby available apartments, rooms, or houses while handling complex filtering and dynamic pricing.

SOLUTION AND CONTRIBUTIONS
• Designed and built the front end using Next.js, focusing on a user-friendly interface for property search and filtering.
• Developed the backend with Prisma and PostgreSQL to handle large-scale data and support real-time property listings.
• Created a dynamic pricing page with a complex UI and robust backend logic to deliver real-time pricing updates.

Jello | A JSON Website Builder

PROBLEM STATEMENT
The client needed a website builder that could dynamically generate static websites by interpreting JSON structures and converting them into HTML and CSS for easy deployment.

SOLUTION AND CONTRIBUTIONS
• Designed and managed the Jello JSON Website Builder, allowing the system to interpret JSON files and automatically generate static websites.
• Developed an engine that renders HTML and CSS in the browser by identifying which components to use from the JSON data.
• Migrated the platform from Node.js 4 to Node.js 12, enhancing performance and modernizing the development stack.

Dynamic Form Builder

Similar to Typeform, users of this application could create as many forms as they wanted and customize each form in various ways. They could choose from many options, including validation. I developed the front end of this practice application to gain skills in React performance optimization.

TILR Chrome Extension

A LinkedIn plugin that extracts information and displays available employment opportunities near the user (for logged-in users only). It was challenging to fit so much data into such a tiny space. I had just created a React-based Chrome plugin, and the firm provided me with an API back end.

Stack Solution Corporate Website

A corporate website with many images that manually cached API responses. While creating the site with Next.js and Strapi, I focused on making the website's response time as brief as possible. I wrote every line of code Instead of using any third-party tools to cache the data. Unfortunately, this website is no longer updated or maintained.

Multi Author Blogging Platform

A Node.js-based, multi-author blogging system similar to Medium. I developed the blogging features, including multi-level commenting, recommendations, full-text searching, an admin dashboard, and more. This was one of my early projects.

Personalized Blog Using Ghost Engine

A blog website I created using the Ghost engine to understand Ghost theme development. The website's front end initially used the Handlebar templating engine—the Ghost method of creating Ghost themes. Then, I moved it to Gatsby. The site was hosted on DigitalOcean. This was a practice project, but I maintained it for over a year.
2016 - 2020

Bachelor's Degree in Software Engineering

Daffodil International University - Dhaka, Bangladesh

Libraries/APIs

Node.js, React.js, Yup, Zod, Winston, WordPress REST API, YouTube API, React.js, React DnD, Formik, AWS Amplify, Antd, Stripe Development, Google Maps Development, Google Maps Development, EJS, Chart.js, Twilio Development, React Hook Form, Moment.js, Lodash, React.js, Socket.IO, Dotenv, Redis Queue, API, WordPress Development, Discord.js, jQuery, Mailchimp API, Stripe Development, Google Calendar API, Back-end APIs, OpenAI API, Auth, Puppeteer, Vimeo API, Google Analytics, REST API, Picasso, OpenAI Assistants API, PostgREST

Tools

Git, GitHub, Slack Development, Jira, Notion Development, Zoom Development, SourceTree, AWS, AWS, AWS, AWS, AWS, CircleCI, Amazon Cognito, React Apollo, Prisma, Stripe Development, Gulp, Mongoose, Ghost, Confluence, Google Sheets Development, Google Docs Development, Google Slides, Figma, Prettier, Babel, Webpack, Cron, Auth0, React Email, Docker Hub, Git, GitLab CI/CD, RabbitMQ, MailChimp Development, MongoDB, ChatGPT, Amazon CloudFront, AWS, Tableau Development, Apache, GitHub Pages, Amazon EKS, Amazon Virtual Private Cloud (VPC), Google Analytics, Apache Airflow

Languages

Java, JavaScript, Java, JavaScript, TypeScript, TypeScript 5, C, Python, TypeScript 3, Python, HTML5, SCSS, GraphQL, CSS3, CSS, ECMAScript (ES6), Ruby, HTML, SQL

Frameworks

Next.js, Redux, tRPC, Angular, Express.js, Serverless Framework, Bulma, Front.js, JSON Web Tokens (JWT), Swagger, Jest, OAuth, Ruby on Rails, Bootstrap, Material UI, Ant Design, Cypress, Fastify

Paradigms

Web UI Design, UI Design, Agile Development, Design Patterns, Software Development, Microservices Development, Scrum Master Consulting, Kanban Project Management, CRUD, REST, Role-based Access Control (RBAC), Redis Pub/Sub, Unit Testing, Database Design, Automation, Back-end Developers, Best Practices, Microservices Architecture, Event-driven Design (EDD), DevOps

Platforms

Visual Studio Development, MacOS, Linux, Firebase, AWS, WooCommerce Design, Oracle Development, AWS Lambda, Amazon EC2, Docker, Heroku, Netlify, DigitalOcean, Cloud Engineering, Cloud Run, Airbyte, Apache Kafka, Linode, YouTube Marketing, EmailJS, PDF.js, Kubernetes, Vercel

Storage

MongoDB, PostgreSQL, MySQL, Redis, AWS, Amazon S3, JSON, Database, Redis Cache, Google Cloud SQL, Database Migration, Firestore, Data Integration, SQL, Database

Industry Expertise

Web Development

Other

Software Development Lifecycle (SDLC), Software Architecture, Data Structures, Algorithms, Web Development, Zustand, System Security, Web Development, Software Requirements Specifications (SRS), Agile Software Testing, Competitive Programming, Web Project Management, Headless CMS, Software Development, Server-side Rendering (SSR), QA Testing, Discrete Mathematics, Operating Systems, Computer Networking, Amazon API, Axios, Styled-components, Intercom, Web Development, Chrome Extension Development, Ajax, Strapi, GatsbyJS, Dashboard, MERN Stack, E-commerce marketing, Full-stack, Front-end, Back-end Developers, Website Builders, React Hooks, React Helmet, NextAuth.js, ESLint, Storybook, Vite, Joi, Bcrypt, CORS, HTTP, HTTP2, Resend, Google Cloud Build, Cloud Storage, GitHub Actions, GitHub Workflows, CSV, CSV File Processing, Integration Testing, Time Management, Empathy, Communication Coaching, Database Schema Design, Relational Database Design, System Design, RESTful Microservices, API, APIs, Supabase, Supabase Auth, Content Writing, Leadership, Security, Team Leadership, Technical Leadership, ClickUp, Discord, Blogging, Core Web Vitals, Full-stack, TypeORM, Planning, Design Strategy, Website Optimization, Page Speed Optimization, API Integration, Accessibility Development, Web Accessibility, Autocomplete, Full-text Search, Back-end Developers, Back-end Developers, Back-end as a Service (BaaS), Mobile Back-end, Architecture, Design Systems, CSS, OpenAI, OpenAI SDK, OpenAI GPT-3 API, GPT-4, Checkout, Cloudflare, Content Management Systems (CMS), Content Marketing Platforms, Customer Portals, Kinde, Authentication, Web Dashboards, Data, Data Analysis, Data Science, Metabase, Bootstrap 5, Scraping, Data Scraping, Website Data Scraping, Deployment, Git, Hono, API Management, API, AWS RDS, ECS, Amazon Route 53, Vimeo Development, Google Analytics 4 (GA4), JSON REST APIs, Email, PDF, SMS Gateways, Email Automation, Payment Gateways, Task Scheduling, SMTP, FTP, SSH, Kubernetes Operations (kOps), DNS

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