Gurjappan is available for hire
Hire GurjappanGurjappan Singh
Verified Expert in Engineering
Full-stack Developer
Chandigarh, India
Toptal member since October 28, 2021
Bio
Gurjappan is a developer keen on TypeScript, React, Express.js, and Web3. He started his career with shell scripting, Python, and PHP, which made him good at handling servers, and he eventually started using JavaScript for the back end and front end. Throughout his seven years of technical journey, Gurjappan has gained a good grasp of design patterns, secure deployment techniques, and scalable solutions for enterprise-level applications.
Portfolio
Scrollmark
JavaScript, Next.js, ChatGPT, Vertex AI, React, Node.js...
Allegis Cruise Automation
Node.js, React, TypeScript, SQL, Go, PostgreSQL, Amazon Web Services (AWS)...
Tenyks
JavaScript, React, Python, Flask, D3.js, Docker, SaaS...
Experience
- Node.js - 6 years
- TypeScript - 6 years
- React - 6 years
- Express.js - 5 years
- JavaScript - 5 years
- Next.js - 5 years
- Amazon Web Services (AWS) - 5 years
- Shell Scripting - 5 years
Availability
Full-time
Preferred Environment
Visual Studio Code (VS Code), Ubuntu, Slack, Discord, Amazon Web Services (AWS), Git
The most amazing...
...thing I've developed is a customer support section for an enterprise which is the first point of human contact for a driverless autonomous car.
Work Experience
Front-end Team Lead
2023 - PRESENT
Scrollmark
- Led the front-end architecture from scratch to build a scalable Next.js-based application that involved complex features like consuming VertexAI and drag and drop functionality, as well as connecting social media networks.
- Followed lean startup methodologies as a pilot batch member in the startup, contributing to the company's growth from zero to one, including fundraising, customer success, and marketing efforts.
- Led a team of three developers, overseeing tasks such as setting up architecture, front-end pipelines, code reviewing, establishing testing frameworks and end-to-end tests, and creating OpenAPI Specifications.
Technologies: JavaScript, Next.js, ChatGPT, Vertex AI, React, Node.js, Amazon Web Services (AWS), Python 3, D3.js, HTML5, CSS, Tailwind CSS, Test-driven Development (TDD), User Interface (UI), REST APIs, Artificial Intelligence (AI), Design Patterns
Full-stack Engineer
2022 - 2023
Allegis Cruise Automation
- Acted as a full-stack developer for an enterprise client using NestJS on the back end and React on the front end. I used Jest for testing and Storybook to build and test interactive UI components.
- Leveraged Twilio to manage calls and conferences between one and five users, implementing advanced features such as call holding, user coaching, muting, and unmuting. Built a new telephony panel that links Twilio features to the UI.
- Worked actively on Docker and CI/CD pipelines on Buildkite. Set up Storycap and brum-bot to establish screenshot tests, making the code reviews for UI easy.
Technologies: Node.js, React, TypeScript, SQL, Go, PostgreSQL, Amazon Web Services (AWS), User Interface (UI), REST APIs
Full-stack Developer | React and Python
2021 - 2022
Tenyks
- Developed a dashboard for a ML-powered firm in React on the front end, Python and Flask on the back end, and AWS as the primary cloud services provider like Cognito.
- Used D3.js and Highcharts to build interactive graphs and charts based on the input data.
- Worked on building bounding boxes on the images and created features to drag, resize, and drop them on images, and created then REST APIs to save them on the go.
- Used Material UI on the front end to build interactive designs.
Technologies: JavaScript, React, Python, Flask, D3.js, Docker, SaaS, Amazon Web Services (AWS), REST APIs, Highcharts, SVG
Core Developer
2021 - 2022
OVRT
- Developed a website that mints NFTs, where I wrote the smart contract and set up ethers.js to be used with the React app.
- Served as one of the core developers on the project from day one. Created a script in Node.js that generates various NFTs based on Photoshop layers. Built additional functionality like rarity checkers.
- Managed the discord server, took part in company podcasts, and explored other areas on Web3 and virtual spaces.
Technologies: React, Amazon Web Services (AWS), Solidity, Web3.js, Smart Contracts, Ethereum, AWS Lambda, Node.js
Senior Software Engineer
2019 - 2021
Trantor Software
- Created a white-labeled application for a travel insurance company built on React which followed domain-driven design using React and TypeScript. I used various design patterns like Bridge and implemented finite state machines.
- Followed test-driven development and various pair programming techniques to mentor and work with peer developers. I followed strict code review protocols, including coverage and various pipeline steps.
- Used Agile for the workflow, which made me proficient in estimations for the development of a feature and on choosing tasks' prioritization.
- Made the application as serverless as possible using AWS Amplify. I started the project without a back end using the axios-mock-adapter, which would toggle based on the environment variable to avoid being blocked.
Technologies: React, TypeScript, Amazon Web Services (AWS)
Software Developer
2017 - 2019
BigBerry Media Private Limited
- Created an in-house customer support management system from scratch. I handled all database operations using stored procedures and showed real-time call data using shell scripts and MySQL database.
- Handled PostgreSQL to handle the user database and basic authentication functions. I also worked on creating a robust authentication system using Node.js and Express.js with a JSON Web Token.
- Used Asterisk and WebRTC for handling calls which included the server set up from scratch. I created a PBX system and applied open-source softphone software to work with it.
- Built the software scalable enough to handle hundreds of calls simultaneously.
Technologies: Node.js, Express.js, AngularJS, Shell Scripting, Asterisk REST Interface (ARI), Asterisk Gateway Interface (AGI), MySQL
Software Engineer
2015 - 2017
Merchant Technologies
- Worked as a junior developer on automation and web-scraping, where my main job included writing scripts that can automate server actions.
- Worked with PHP, Python, and Linux operating systems, eventually used PHP, WordPress, and Shopify to create multiple websites ranging from admin dashboards to eCommerce websites.
- Created cronjobs that would automate notifications based on data scraped from multiple websites in Python using BeautifulSoup and Selenium.
- Used various security measures for a website and vulnerabilities like LFI, RFI, SQL injection, c99 shells, and XSS, and practices to avoid these mistakes.
Technologies: PHP 5, Python 3
Experience
Volt AI
http://volt.aiCreated a React app for an ML-powered security system application that works on threat detection solutions. I primarily handled the front-end side of the application. After completing the MVP, I was introduced and added more features, refactoring previous code and making the app more scalable and user-friendly.
Added features like Google Maps support with polygons and custom camera markers for FOVs, creating several drag-and-drop features, bounding boxes, 3D maps using magic plans, and Twilio integration to call 911.
Added features like Google Maps support with polygons and custom camera markers for FOVs, creating several drag-and-drop features, bounding boxes, 3D maps using magic plans, and Twilio integration to call 911.
Junk Removal Service Application
http://www.haulshare.coA DERN—DynamoDB, Express, React, and Node.js—stack app developed for a US-based startup that provides junk removal and dumpster delivery services.
I was responsible for end-to-end development, including the back end, front end, and deployment.
I was responsible for end-to-end development, including the back end, front end, and deployment.
Juni Web3
A Web3-based social app built to provide utility for token holders within the same project. Juni allows users to log in using a MetaMask account, access projects corresponding to the tokens they hold, and connect with other users with similar interests. It's a white-labeled application for project admins who want to connect their teams.
As a core developer, I architected the whole application and wrote the authentication schema based on wallet address, signed messages using ethers, and Infura to read details for a specific user.
As a core developer, I architected the whole application and wrote the authentication schema based on wallet address, signed messages using ethers, and Infura to read details for a specific user.
Education
2011 - 2015
Bachelor's Degree in Computer Science
Punjab Technical University - Punjab, India
Skills
Libraries/APIs
React, React Router, REST APIs, Node.js, D3.js, Highcharts, Web3.js
Tools
Amazon Cognito, Slack, Git, Asterisk REST Interface (ARI), ChatGPT
Languages
HTML5, JavaScript, TypeScript, CSS, Python 3, SQL, PHP 5, Solidity, Python, Go, GraphQL
Frameworks
Next.js, Jest, Express.js, AngularJS, Flask, Tailwind CSS
Paradigms
REST, Design Patterns, Test-driven Development (TDD)
Platforms
Linux, Amazon Web Services (AWS), Ubuntu, Ethereum, AWS Lambda, Docker, Visual Studio Code (VS Code), Vertex AI
Storage
Amazon DynamoDB, MySQL, PostgreSQL
Other
Shell Scripting, HTTP REST, SVG, Ethers.js, User Interface (UI), Artificial Intelligence (AI), Vite, Discord, Asterisk Gateway Interface (AGI), Smart Contracts, SaaS, Agentic AI
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