Kevin is available for hire
Hire KevinKevin Isaac
Verified Expert in Engineering
Full-stack Developer
Chennai, Tamil Nadu, India
Toptal member since June 6, 2022
Bio
Kevin is a full-stack developer with 10 years of professional experience who currently works as the chief architect of a custom software development firm. He specializes in technologies like Python, FastAPI, Flask, PostgreSQL, React, and React Native. Kevin has developed and architected more than a dozen web and mobile apps for businesses and is an expert in translating business requirements into functional software.
Portfolio
Zephony
Python, Flask, React, PostgreSQL, React Native, REST, JavaScript, SQL, CSS...
Freelance
API Architecture, CSS, HTML, React, JavaScript, Python, Flask, PostgreSQL...
Zucumber Technologies
JavaScript, CSS, HTML, Front-end, Front-end Development, REST APIs, HTML5...
Experience
- PostgreSQL - 10 years
- Python - 10 years
- JavaScript - 7 years
- React Native - 7 years
- REST APIs - 6 years
- React - 6 years
- API Architecture - 5 years
- FastAPI - 3 years
Preferred Environment
Linux, Postman, Slack, Vim Text Editor, GitHub, MacOS, Cursor AI, Vite, React Native
The most amazing...
...software I've built is an AI-powered skin analysis platform that reached 2000+ users in the first few weeks of its launch.
Work Experience
Senior Software Engineer/Architect
2017 - PRESENT
Zephony
- Increased operation efficiency by 70% by developing a custom software platform to completely digitize a client's business. It's been used by the client's entire team, including sales and operations, for more than three years.
- Built an inventory management web app used to send more than 8,000 custom-generated quotations to potential customers in the past five years.
- Created a custom eCommerce platform for a client using Flask, Python, and an admin panel to manage products, sales, and customer inquiries.
- Built an online sports visualization and custom quote generation platform for a big sports company based in Italy.
- Built a React Native app complementing the custom CRM I built for a training agency. It was used by the students to upload pictures and manage albums, see and manage their upcoming appointments and classes, and track their upcoming payment details.
- Built a mobile app using React Native for a Luxembourg startup, which allowed consumers to discover service providers on their platform and make appointments by booking custom slots and doing online payments with ease.
Technologies: Python, Flask, React, PostgreSQL, React Native, REST, JavaScript, SQL, CSS, UX Architecture, Architecture, Full-stack, Front-end, Linux, Slack, Back-end, Back-end Development, Front-end Development, Postman, REST APIs, API Architecture, HTML5, Twilio API, NGINX, Single-page Applications (SPAs), DigitalOcean, MongoDB, HTML, Web Applications, Automation, JSON, Google Analytics, Matomo, Piwik, Git, Writing & Editing, Content Writing, Software Development, Relational Data Mapping, Data Structures, CTO, Team Management, Product Management, Project Management, Mobile, APIs, NoSQL, SQLAlchemy, Redis, Python 3, Celery, Cron, Responsive Web Design (RWD), User Interface (UI), User Experience (UX), TypeScript, PostgreSQL 9, Automated Testing, GitHub, Python API, Web Development, Software Architecture, Leadership, UX Design, UI Design, Redux, Pandas, Pytest, CircleCI, Mobile Development, Cypress, Amazon Web Services (AWS), Node.js, API Integration, WebSockets, Scalable Application, Scalable Architecture, Cloud, Version Control, UI Development, CI/CD Pipelines, DevOps, Google Cloud Platform (GCP), Docker, Caching, Hosting, CSS3, Responsive Design, Databases, Minimum Viable Product (MVP), React Router, React Query, Documentation, Markdown, FastAPI, Design Systems, Web App Development, UI Components, B2B, Testing, Remix, API Development, Web Crawlers, Artificial Intelligence (AI), Email Automation, Responsive Web Apps, Front-end Architecture, AI Agents, Large Language Models (LLMs), Logistics, Freight, Generative Artificial Intelligence (GenAI), Prompt Engineering, Next.js, GraphQL, React Testing Library, Jest, RESTFul APIs, Google, Figma to HTML, OpenAI, Retrieval-augmented Generation (RAG), Vector Databases, Supabase, API Design, RabbitMQ, Express.js, Azure, ChatGPT API, OpenAI GPT-3 API, Apollo, Process Automation, n8n, Workflow Automation & System Integration, Vite, Tailwind CSS, System Architecture, Chatbots, Django, Containerization, Heroku, Render, Twilio, SMS, Kubernetes, Amazon EKS, E-learning, Cursor AI, ChatGPT, Responsive UI, Material UI, WCAG 2, Web Content Accessibility Guidelines (WCAG), Web Accessibility, Mobile First, Progressive Web Applications (PWAs), Marketplaces, Customer Relationship Management (CRM), Zapier, Stripe API, Webhooks, CSV File Processing, Dashboards, Reporting Automation, Security, OpenAI API, Document Parsing, Stripe, eCommerce, Agentic AI, SQLite, Claude, Python Asyncio, Axios, JSON Web Tokens (JWT), Role-based Access Control (RBAC), Shell, Containers, GitHub Actions, Data Analysis, Conversational AI, Svelte
Full-stack Developer
2017 - 2018
Freelance
- Developed a web portal that used data from invoices that had been created for five years and were used to create an analytics dashboard for better decision-making by key stakeholders.
- Collaborated with an AI developer who wrote the computer vision module to read data from PDF files and used the data for the dashboard.
- Created the entire back-end and API architecture that imported data from CSV files and processed the information in real-time to feed the dashboard while allowing hot editing.
- Helped a client move his entire blog and payment platform to a new server while retaining all the data and settings.
- Worked with a client to fix authentication issues on his platform while integrating with Okta for user identity management.
Technologies: API Architecture, CSS, HTML, React, JavaScript, Python, Flask, PostgreSQL, REST APIs, Full-stack Development, UX Architecture, Architecture, Full-stack, Front-end, MySQL, MariaDB, Linux, SQL, Back-end, Back-end Development, Front-end Development, Postman, HTML5, NGINX, Single-page Applications (SPAs), DigitalOcean, Web Applications, JSON, Git, Technical Writing, Software Development, Blogging, Relational Data Mapping, Data Structures, Product Management, Project Management, APIs, SQLAlchemy, Redis, Python 3, Celery, Cron, Responsive Web Design (RWD), User Interface (UI), User Experience (UX), PostgreSQL 9, GitHub, Python API, Web Development, Software Architecture, UX Design, Pytest, Alembic, Cloud, Version Control, UI Development, DevOps, Hosting, CSS3, Responsive Design, Databases, Minimum Viable Product (MVP), Design Systems, Web App Development, UI Components, B2B, Testing, Remix, API Development, Web Crawlers, Responsive Web Apps, Front-end Architecture, GraphQL, Jest, RESTFul APIs, Google, Figma to HTML, API Design, RabbitMQ, Express.js, Node.js, Process Automation, System Architecture, Heroku, Responsive UI, WCAG 2, Web Content Accessibility Guidelines (WCAG), CSV File Processing, Dashboards, Security, Document Parsing, Stripe, SQLite, Axios, JSON Web Tokens (JWT), Bootstrap, Shell
Front-end Developer
2016 - 2017
Zucumber Technologies
- Implemented the front-end of their web application in HTML, CSS, and JavaScript.
- Worked with the designer to convert the designs to a functional Single Page Application.
- Collaborated with the back-end team to develop API architecture and consumer the REST API on the front-end.
Technologies: JavaScript, CSS, HTML, Front-end, Front-end Development, REST APIs, HTML5, Single-page Applications (SPAs), DigitalOcean, Web Applications, JSON, Git, Software Development, Relational Data Mapping, APIs, Responsive Web Design (RWD), User Interface (UI), GitHub, Web Development, Software Architecture, UX Design, Version Control, UI Development, Hosting, CSS3, Responsive Design, Minimum Viable Product (MVP), Web App Development, UI Components, Testing, API Development, Responsive Web Apps, Front-end Architecture, RESTFul APIs, Figma to HTML, PHP, API Design, System Architecture, Responsive UI, Web Content Accessibility Guidelines (WCAG), Backbone.js, Marionette.js, LAMP, Memcached, GitLab, GitLab CI/CD, SQLite, Bootstrap
Chief Technology Officer
2015 - 2016
Freeth Technologies
- Created a detailed and well-crafted API and code architecture in Python.
- Implemented a social networking site using the cutting-edge graph database called Titan (now JanusGraph).
- Contributed to the front end of the application built in Backbone.js.
Technologies: API Architecture, Back-end Development, CSS, Flask, Front-end Development, Full-stack Development, HTML, Python, JavaScript, Architecture, Full-stack, Front-end, MySQL, MariaDB, JanusGraph, Back-end, REST APIs, HTML5, DigitalOcean, Slack, Web Applications, JSON, Git, Software Development, Data Structures, CTO, Project Management, APIs, NoSQL, Python 3, Cron, Responsive Web Design (RWD), User Interface (UI), User Experience (UX), GitHub, Python API, Web Development, Software Architecture, Leadership, UX Design, Cloud, Version Control, UI Development, DevOps, Hosting, CSS3, Databases, Minimum Viable Product (MVP), Social Networks, Web App Development, Testing, API Development, Front-end Architecture, RESTFul APIs, PHP, API Design, System Architecture, Responsive UI, CSV File Processing, GitLab, GitLab CI/CD, JSON Web Tokens (JWT), Shell
Experience
Custom CRM and Student Mobile App
This web and mobile platform has helped our client digitize their entire business, a leading talent training agency based in Milan, Italy. Their entire sales and operations team has been using the platform for over three years, increasing their efficiency by over 70%.
The web app includes a module for the sales team to directly track and contact marketing-qualified leads and follow up with them via email and WhatsApp messages right from within the platform. It also includes a module to onboard a new client, from loading information to generating a custom contract for the client, and another module for the teachers and students. Automation removed a considerable part of the client's workload and allowed them to move efficiently.
The mobile app for this platform was built in React Native so that students could manage their profiles and accounts. Some of the features include:
• a calendar with in-app notifications for the students regarding their upcoming classes.
• a separate payment page where they can track all their upcoming payment and EMI details.
• an album view where they can upload and showcase their pictures to share with potential agents.
The web app includes a module for the sales team to directly track and contact marketing-qualified leads and follow up with them via email and WhatsApp messages right from within the platform. It also includes a module to onboard a new client, from loading information to generating a custom contract for the client, and another module for the teachers and students. Automation removed a considerable part of the client's workload and allowed them to move efficiently.
The mobile app for this platform was built in React Native so that students could manage their profiles and accounts. Some of the features include:
• a calendar with in-app notifications for the students regarding their upcoming classes.
• a separate payment page where they can track all their upcoming payment and EMI details.
• an album view where they can upload and showcase their pictures to share with potential agents.
Shloak | Multi-industry Appointment Booking Platform (Web and Mobile)
An appointment booking platform where consumers can book appointments with vendors across various industries via the mobile app, and vendors can manage their staff, services, and appointments from their vendor panel.
I was the lead architect who came up with the database and API architecture and also led a team of designers and developers overseeing the whole development of the project. I also assisted the back-end developer in effectively writing the business logic in Python.
I built the consumer mobile app from the ground up using React Native. Some of the features include:
• the customers being able to browse different service providers using a list or a map view
• the ability to find slots and book appointments from within the app
• getting real-time notifications about the status of their appointments.
I was the lead architect who came up with the database and API architecture and also led a team of designers and developers overseeing the whole development of the project. I also assisted the back-end developer in effectively writing the business logic in Python.
I built the consumer mobile app from the ground up using React Native. Some of the features include:
• the customers being able to browse different service providers using a list or a map view
• the ability to find slots and book appointments from within the app
• getting real-time notifications about the status of their appointments.
AI-powered Skincare Platform
https://www.knowurskin.com/An AI-powered skin analysis app that analyzes users' facial images and provides a detailed report of all the skin conditions detected, ratings based on a proprietary scoring algorithm, and recommended products.
It has a SaaS functionality where users can subscribe to track their weekly and monthly progress.
I was the architect and the full-stack developer building both the front end and the back end of the app. The platform saw 2000+ users in the first few weeks of its launch.
It has a SaaS functionality where users can subscribe to track their weekly and monthly progress.
I was the architect and the full-stack developer building both the front end and the back end of the app. The platform saw 2000+ users in the first few weeks of its launch.
NoleggioCampi | Visualized Sports Quote Generation Platform
https://noleggiocampi.it/An online sports field visualization and quotation generation platform (web app) that included managing thousands of images and rendering them correctly, based on the user input through the browser.
Corporations and institutions use this platform to generate more than 1000 quotations for their customized on-demand sports field setup requirement.
I oversaw the complete architecture of the API, DB, and code base, and was solely in charge of the back-end of the web application.
I also collaborated with the front-end developer and consulted with him to build and launch the entire application live successfully.
Corporations and institutions use this platform to generate more than 1000 quotations for their customized on-demand sports field setup requirement.
I oversaw the complete architecture of the API, DB, and code base, and was solely in charge of the back-end of the web application.
I also collaborated with the front-end developer and consulted with him to build and launch the entire application live successfully.
Mi Alma | eCommerce App for Accessories
A custom-built eCommerce web app. I was in charge of developing the API and code architecture and building the application's back end using Python and MongoDB.
I also collaborated with the front-end developer, documented the REST API architecture, and conducted regular technical discussions, testing, and bug fixing.
I built the project from the ground up with the front-end developer, translating the requirements and the application wire-frame we received from the client.
I also collaborated with the front-end developer, documented the REST API architecture, and conducted regular technical discussions, testing, and bug fixing.
I built the project from the ground up with the front-end developer, translating the requirements and the application wire-frame we received from the client.
AdvisorScoop | Content Sharing Platform for Financial Advisors
A content sharing and newsletter management platform for financial advisors based in Singapore. The web app was built in Python and React.
I designed the architecture for the platform and led a team of designers and front and back-end developers right from prototyping the application.
I also helped the back-end developer with Python and PostgreSQL DB schema definitions and contributed to the React code-base and the front-end developer.
In addition to the content creation and management module, the application also had some advanced scheduling functionalities that allowed the users to schedule articles automatically to their readers/prospects via email.
I designed the architecture for the platform and led a team of designers and front and back-end developers right from prototyping the application.
I also helped the back-end developer with Python and PostgreSQL DB schema definitions and contributed to the React code-base and the front-end developer.
In addition to the content creation and management module, the application also had some advanced scheduling functionalities that allowed the users to schedule articles automatically to their readers/prospects via email.
Freeth | Social Networking Web App
A social network website that connects people based on interests and shared passion. I was the chief architect of the platform and was responsible for making the technology decision and coming up with the overall architecture.
I also built the back end in Python with another developer and had regular brainstorming sessions to solve interesting engineering problems. The back end was built in Python Flask. We used PostgreSQL to store relational data and JanusGraph (then called Titan), a graph database, as the main datastore to store and query non-relational data that is ideal for a social networking site.
I was also responsible for developing the REST API and database schema. I collaborated with the front-end developer and contributed to the front end, a single page application.
I also built the back end in Python with another developer and had regular brainstorming sessions to solve interesting engineering problems. The back end was built in Python Flask. We used PostgreSQL to store relational data and JanusGraph (then called Titan), a graph database, as the main datastore to store and query non-relational data that is ideal for a social networking site.
I was also responsible for developing the REST API and database schema. I collaborated with the front-end developer and contributed to the front end, a single page application.
Analytics Platform for an Enterprise SaaS Application
https://ordwaylabs.com/Contributed to migrating and building a new analytics platform for an enterprise SaaS product. The platform was built in legacy frameworks and was used by existing customers, including fortune 500 companies.
I was part of a small team tasked with building the new analytics module that included Google's Looker framework. I worked with a team that consisted of a database engineer, a tester, a project manager, and a front-end developer to architect and build the system using Python Flask, PostgreSQL, and React.
I was part of a small team tasked with building the new analytics module that included Google's Looker framework. I worked with a team that consisted of a database engineer, a tester, a project manager, and a front-end developer to architect and build the system using Python Flask, PostgreSQL, and React.
AI-powered Arabic OCR and Translation App
An online platform where users can upload their PDF and image files and extract and translate or transliterate the original Arabic text to English.
The app supports two platforms (Qari & Mistral) for OCR, one of which is a well-trained HuggingFace model on Arabic text. In addition, the app uses LLM integrations like OpenAI and Mistral AI to translate and transliterate the original document.
I worked closely with a product designer to architect, build, and deploy the entire platform using Python FastAPI and React, using PostgreSQL as the data store with Celery background jobs.
The application uses Runpod to run the custom-hosted Qari model for better performance and an improved end-user experience.
The app supports two platforms (Qari & Mistral) for OCR, one of which is a well-trained HuggingFace model on Arabic text. In addition, the app uses LLM integrations like OpenAI and Mistral AI to translate and transliterate the original document.
I worked closely with a product designer to architect, build, and deploy the entire platform using Python FastAPI and React, using PostgreSQL as the data store with Celery background jobs.
The application uses Runpod to run the custom-hosted Qari model for better performance and an improved end-user experience.
Education
2011 - 2015
Bachelor's Degree in Computer Engineering
Karunya University - India
Skills
Libraries/APIs
React, REST APIs, API Development, Twilio API, SQLAlchemy, Python API, Node.js, React Router, OpenAI API, Stripe, Python Asyncio, Pandas, React Query, React Testing Library, Backbone.js, Marionette.js, Stripe API, TanStack Table, RQ, Redis Queue, Hugging Face Transformers, Pydantic
Tools
Postman, Vim Text Editor, GitHub, Figma to HTML, Slack, NGINX, Git, Celery, Figma, ChatGPT, Shell, Google Analytics, Matomo, Piwik, Cron, Looker, Webpack, Pytest, CircleCI, RabbitMQ, n8n, Amazon EKS, Zapier, GitLab, GitLab CI/CD, Claude, Docker Compose, Docker Hub
Languages
Python, JavaScript, HTML, CSS, HTML5, Python 3, SQL, TypeScript, CSS3, Markdown, PHP, GraphQL
Frameworks
Flask, React Native, JSON Web Tokens (JWT), Remix, Next.js, Express.js, Django, Material UI, Svelte, Redux, Alembic, Cypress, Jest, Tailwind CSS, Bootstrap
Paradigms
REST, API Architecture, Responsive Web Design (RWD), Role-based Access Control (RBAC), UX Design, UI Design, Mobile Development, Scalable Application, DevOps, Hosting, B2B, Testing, Automation, Automated Testing
Storage
PostgreSQL, MySQL, MariaDB, JSON, SQLite, Redis, Databases, JanusGraph, MongoDB, NoSQL, Graph Databases, Titan Graph, Memcached
Platforms
DigitalOcean, Mobile, Docker, Heroku, Twilio, LAMP, Linux, Amazon Web Services (AWS), Google Cloud Platform (GCP), MacOS, Azure, Kubernetes, RunPod
Industry Expertise
Project Management, E-learning
Other
UX Architecture, Architecture, Full-stack, Full-stack Development, Back-end, Back-end Development, Front-end, Front-end Development, Single-page Applications (SPAs), Web Applications, Software Development, APIs, User Experience (UX), Web Development, English, FastAPI, Web App Development, UI Components, Front-end Architecture, Cursor AI, Large Language Models (LLMs), Generative Artificial Intelligence (GenAI), RESTFul APIs, Google, API Design, Responsive UI, Mobile First, Writing & Editing, Technical Writing, Relational Data Mapping, CTO, User Interface (UI), PostgreSQL 9, Software Architecture, Leadership, API Integration, WebSockets, Scalable Architecture, Cloud, Version Control, UI Development, CI/CD Pipelines, Responsive Design, Minimum Viable Product (MVP), Web Crawlers, Artificial Intelligence (AI), Email Automation, Responsive Web Apps, AI Agents, Logistics, Freight, Prompt Engineering, OpenAI, Retrieval-augmented Generation (RAG), Vector Databases, ChatGPT API, OpenAI GPT-3 API, Process Automation, Vite, System Architecture, Chatbots, Containerization, Render, SMS, WCAG 2, Web Content Accessibility Guidelines (WCAG), Web Accessibility, Progressive Web Applications (PWAs), Marketplaces, Customer Relationship Management (CRM), Webhooks, CSV File Processing, Dashboards, Security, Axios, Containers, GitHub Actions, Conversational AI, Scheduling, Content Writing, Blogging, Data Structures, Team Management, Product Management, Caching, Social Networks, Documentation, Design Systems, Supabase, Apollo, Workflow Automation & System Integration, Reporting Automation, Document Parsing, eCommerce, Agentic AI, Data Analysis, Gemini, Gemini API, PWA, Razorpay, SaaS, Hugging Face, Mistral AI, AI Translation, Optical Character Recognition (OCR), PDF, Animation
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