Maria is available for hire
Hire MariaMaria Zacharia
Verified Expert in Engineering
Node.js Full-stack Developer
Bengaluru, Karnataka, India
Toptal member since December 1, 2021
Bio
Maria is a senior software engineer with 8 years of experience taking platforms from concept to production. Her background spans Koch Industries, Oracle, and building her own startups. She combines full-stack expertise with hands-on experience in applied AI and AI-assisted development. From back-end architecture and cloud infrastructure to intuitive frontends, Maria takes ownership of building reliable, scalable software that solves real business problems.
Portfolio
Vector Scale Labs
React, Next.js, Node.js, Material UI, PostgreSQL, Amazon RDS, DigitalOcean...
Flint Hills Resources Ltd - Main
TypeScript, React, Serverless, JavaScript, Neo4j, Amazon Web Services (AWS)...
Ztadium games LLC
DigitalOcean, Node.js, MySQL, React, Docker, Back-end Architecture, JavaScript...
Experience
- Node.js - 8 years
- TypeScript - 8 years
- Amazon Web Services (AWS) - 8 years
- Next.js - 3 years
- AI Agents - 2 years
- AI Architecture - 2 years
- Model Context Protocol (MCP) - 2 years
- OpenAI - 1 year
Work Experience
Co-founder | CTO
2024 - 2026
Vector Scale Labs
- Led a team of 3 engineers to build and launch Haulistic and Chatwise, owning technical architecture, hands-on full-stack development, and delivery from concept to production.
- Built Haulistic’s multi-agent AI website editor, translating conversational requests and reference websites into storefront design changes so merchants can customize their sites without writing code.
- Implemented Model Context Protocol (MCP) integrations that expose platform capabilities to AI assistants, enabling users to perform business operations through natural-language requests.
- Developed Chatwise’s Instagram and WhatsApp messaging platform, supporting close to 50,000 conversations per month. Built AI-powered categorization using user-defined categories and automated replies informed by live Shopify product data.
- Engineered Haulistic’s Next.js storefronts and Node.js/PostgreSQL back end, covering catalog, inventory, orders, and payment integrations for merchants processing approximately $50,000–$100,000 in monthly payments.
- Established CI/CD pipelines, end-to-end and load testing, and production monitoring. Mentored engineers, guided technical decisions, and managed releases and ongoing platform reliability.
Technologies: React, Next.js, Node.js, Material UI, PostgreSQL, Amazon RDS, DigitalOcean, Meta Ads, Instagram API, OpenAI, OpenAI API, Pinecone, Tailwind CSS, Prisma, Vite, Vector Databases, Front-end Development, CSS, AI Tools, Cursor AI, Vercel, Claude Code, RAG Architecture, RAG Pipelines, Retrieval-augmented Generation (RAG), Server-side Rendering (SSR), Artificial Intelligence (AI), AI Architecture, AI Engineering, Large Language Models (LLMs), Software Engineering, Model Context Protocol (MCP), AI Agents, Multi-agent Systems, Knowledge Graphs, LLM Agents, Single-page Applications (SPAs), Agentic AI, Software Architecture, Architecture, Cloud Architecture, GitLab CI/CD, Infrastructure as Code (IaC), API Architecture, Component-based Architecture, Design Systems, Microservices, Claude, Codex, CSS3, Figma, Redis, Datadog, Prometheus, API Design, Solution Architecture, Python, Observability Tools, Agile Software Development, Cloud, Startups, System Architecture, Team Leadership, Agentic Workflow Design, eCommerce, React Native, Mobile Development, Flutter, Marketplaces, UI Design, UX Design, Data Engineering, AI-assisted Development, Stakeholder Management, AI Evaluation, Azure
Full-stack Engineer
2022 - 2024
Flint Hills Resources Ltd - Main
- Developed comprehensive dashboards designed to facilitate the creation, management, and updating of economic event data, ensuring streamlined processes and improved data accuracy.
- Developed back-end data pipelines to process large-scale economic event data and execute intricate calculations, yielding insights into expected costs and inventory impacts.
- Designed and optimized Cypher queries for Neo4j Graph Database to efficiently store, retrieve, and analyze economic event data, enabling faster calculations and accurate cost predictions.
Technologies: TypeScript, React, Serverless, JavaScript, Neo4j, Amazon Web Services (AWS), Jest, Front-end Development, CSS, Redux, Software Engineering, Single-page Applications (SPAs), Software Architecture, Cloud Architecture, GitLab CI/CD, API Architecture, Component-based Architecture, Design Systems, Microservices, CSS3, Graph Databases, Enterprise Architecture, Solution Architecture, Agile Software Development, Cloud, System Architecture, Team Leadership
Full-stack Developer (Node.js and MySQL)
2022 - 2022
Ztadium games LLC
- Dockerized the back-end Node.js application and set up deployment on the DigitalOcean Apps Platform, making it easy to scale the application based on load.
- Added necessary DB indexes for query optimization and set up database migrations using Knex.js.
- Mentored the existing team on the back-end development and deployment process and produced all required documents for future reference.
- Helped the client fix critical customer issues on the React-based front end. Also, fixed issues related to connection pooling on the back end.
Technologies: DigitalOcean, Node.js, MySQL, React, Docker, Back-end Architecture, JavaScript, Postman, Technical Leadership, Amazon Elastic Container Service (ECS), Server-side Rendering (SSR), Software Engineering, Single-page Applications (SPAs), Software Architecture, Architecture, Cloud Architecture, GitLab CI/CD, Infrastructure as Code (IaC), API Architecture, Component-based Architecture, Design Systems, Microservices, CSS3, Google Cloud Platform (GCP), API Design, Solution Architecture, Agile Software Development, Cloud, Startups, System Architecture, Team Leadership
Back-end Engineer
2021 - 2022
Percent
- Implemented a reliable and stable webhook messaging system based on the transactional-outbox pattern using AWS Lambda, SQS, Node.js, and TypeScript.
- Built a payment processing system to accept donations for good causes using Node.js and TypeScript. Submitted multiple technical proposals and integrated with Adyen for handling payments.
- Led the team to move from manual infrastructural management in AWS to complete automation using Terraform.
- Built multiple features, including 2FA and customized hosted solutions for easier product integration with businesses.
- Ensured all functionalities were covered by end-to-end tests, using Jest, preventing potential bugs and downtime.
Technologies: Node.js, TypeScript, PostgreSQL, Jest, AWS Lambda, Terraform, Serverless, Back-end, Docker, Amazon Web Services (AWS), Back-end Development, APIs, Relational Database Services (RDS), DevOps, CI/CD Pipelines, NoSQL, Stripe, Stripe Connect, REST APIs, Git, AWS CloudFormation, API Integration, Agile, Adyen Payments, Software Design, Lambda Functions, Back-end Architecture, API Gateways, AWS Cloud Architecture, Amazon DynamoDB, JavaScript, Serverless Framework, Postman, Jira, Technical Leadership, Microservices Architecture, Amazon Elastic Container Service (ECS), Pagination, Lambda Architecture, Server-side Rendering (SSR), Software Engineering, Software Architecture, Architecture, Cloud Architecture, GitLab CI/CD, Infrastructure as Code (IaC), API Architecture, Microservices, CSS3, Google Cloud Platform (GCP), Redis, Datadog, Prometheus, API Design, Solution Architecture, Observability Tools, Agile Software Development, Cloud, Startups, System Architecture, Team Leadership, Stakeholder Management
Co-founder | CTO
2020 - 2021
Hire the Author
- Designed and developed a highly scalable back-end system based on a serverless architecture with over 15 microservices using Node.js. Used Serverless framework for deploying major AWS services like Lambda, DynamoDB, SQS, and Cognito.
- Implemented a highly scalable Serverless Chat system using API Gateway Websockets, DynamoDB, AWS Lambda, and SQS.
- Integrated multiple third-party services like Stripe for payments, Amplitude for analytics, and Google Maps API for location suggestions.
- Developed a responsive front-end web application based on Angular. Followed Angular clean architecture to achieve a highly structured codebase. Created UX designs using Figma.
- Interacted with a lot of customers and acted upon customer feedback to improve the user experience.
Technologies: Angular, AWS Lambda, Amazon DynamoDB, Node.js, TypeScript, Stripe API, Google Maps API, Amplitude, Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (SNS), Amazon S3 (AWS S3), Amazon CloudFront CDN, Figma, Serverless Framework, Amazon Web Services (AWS), Back-end Development, APIs, Bootstrap, DevOps, NoSQL, Stripe, Stripe Connect, REST APIs, GraphQL, Git, GitHub, Full-stack, Front-end, WebSockets, AWS CloudFormation, Front-end Development, Responsive UI, API Integration, HTML, Webpack, Full-stack Development, Serverless Architecture, Google Sheets, User Interface (UI), User Experience (UX), Software Design, Serverless, Lambda Functions, Back-end Architecture, API Gateways, AWS Cloud Architecture, Amazon Cognito, JavaScript, Postman, Jira, Technical Leadership, Microservices Architecture, Amazon Elastic Container Service (ECS), Pagination, CTO, Lambda Architecture, CSS, Server-side Rendering (SSR), Software Engineering, Single-page Applications (SPAs), Software Architecture, Architecture, Cloud Architecture, GitLab CI/CD, Infrastructure as Code (IaC), API Architecture, Component-based Architecture, Design Systems, Microservices, CSS3, Google Cloud Platform (GCP), Datadog, Prometheus, API Design, Solution Architecture, Python, Observability Tools, Agile Software Development, Cloud, Startups, System Architecture, Team Leadership, Marketplaces, UI Design, UX Design, Stakeholder Management, Azure
Applications Engineer
2018 - 2020
Oracle
- Developed a notepad web component for adding, labeling, and collaborating notes inside a service request application.
- Built a back-end custom logger application for collecting and filtering client-side logs using Node.js. Built a web component to interact with the back-end by sending logs in fixed time intervals.
- Made a back-end application to fetch activity feeds pertaining to a service request object. Supported feed type-based and keyword-based filtering and pagination of feed records.
- Created web components to compose a message and display the message thread. Developed a generic component to handle multiple message types within the context of a service request.
- Developed dynamic UI components, highly customizable web components that use a metadata file to render the UI at runtime. Integrated dynamic form and table components to support the extensibility feature.
Technologies: Oracle JavaScript Extension Toolkit (JET), JavaScript, Node.js, MongoDB, SQL, Docker, APIs, MySQL, React, Relational Database Services (RDS), NoSQL, REST APIs, Git, Java, Full-stack, Front-end, Front-end Development, Responsive UI, HTML, Agile, Full-stack Development, TypeScript, User Interface (UI), Postman, Jira, Technical Leadership, Pagination, Software Engineering, Spring, Architecture, Cloud Architecture, GitLab CI/CD, API Architecture, Component-based Architecture, Design Systems, Microservices, CSS3, API Design, Enterprise Architecture, Solution Architecture, Agile Software Development, Cloud, System Architecture, Team Leadership, UI Design, UX Design, Stakeholder Management
Project History
Chatwise — AI-powered Messaging and Automation Platform
https://chatwise.so/Chatwise is an AI-powered customer messaging and automation platform for Instagram and WhatsApp, handling close to 50,000 conversations per month. As co-founder and CTO, I led its architecture and hands-on development across messaging, AI workflows, and team collaboration.
I built an AI-powered conversation categorization that lets businesses define their own categories and automatically organize inquiries by intent. This helps teams identify sales inquiries, support requests, and conversations that need attention. I also developed automated replies informed by live Shopify product data, connecting AI responses to the merchant's catalog.
The shared inbox brings together messages and comments, with comment-to-DM automation, saved replies, team assignment, and conversation management. I integrated Meta APIs to support account connections and messaging workflows across web and mobile experiences.
The back end uses Node.js, TypeScript, and PostgreSQL, with Amazon SQS and background workers for asynchronous processing of messaging events and automation tasks. I owned integrations, deployment pipelines, testing, and production operations, combining LLM capabilities with messaging infrastructure to support customer service and sales.
I built an AI-powered conversation categorization that lets businesses define their own categories and automatically organize inquiries by intent. This helps teams identify sales inquiries, support requests, and conversations that need attention. I also developed automated replies informed by live Shopify product data, connecting AI responses to the merchant's catalog.
The shared inbox brings together messages and comments, with comment-to-DM automation, saved replies, team assignment, and conversation management. I integrated Meta APIs to support account connections and messaging workflows across web and mobile experiences.
The back end uses Node.js, TypeScript, and PostgreSQL, with Amazon SQS and background workers for asynchronous processing of messaging events and automation tasks. I owned integrations, deployment pipelines, testing, and production operations, combining LLM capabilities with messaging infrastructure to support customer service and sales.
Haulistic — AI-powered eCommerce Platform
https://haulistic.io/Haulistic is an AI-powered e-commerce platform for building and managing online stores. As co-founder and CTO, I led its architecture, mentored engineers, and drove hands-on development across storefronts, merchant tools, and integrations. It supports merchants processing approximately $50,000–$100,000 in monthly payments.
I built a multi-agent AI website editor that lets merchants customize storefronts through conversation, using reference websites to guide design changes. I also implemented Model Context Protocol (MCP) integrations so users can create products, update inventory, and access store data through ChatGPT and Claude.
The platform uses React/Next.js, TypeScript, Node.js/Express, and PostgreSQL/Prisma. I developed the seller dashboard for catalog, inventory, orders, returns, and analytics, alongside payment gateway integrations and Instagram shopping features that connect social content to purchasable products.
I implemented OAuth, webhook processing, and background jobs, plus custom domains, automatic SSL, CDN image optimization, and Elastic APM for tracing and observability. I also owned CI/CD, automated testing, and production delivery, with a focus on storefront SEO, Core Web Vitals, and reliability.
I built a multi-agent AI website editor that lets merchants customize storefronts through conversation, using reference websites to guide design changes. I also implemented Model Context Protocol (MCP) integrations so users can create products, update inventory, and access store data through ChatGPT and Claude.
The platform uses React/Next.js, TypeScript, Node.js/Express, and PostgreSQL/Prisma. I developed the seller dashboard for catalog, inventory, orders, returns, and analytics, alongside payment gateway integrations and Instagram shopping features that connect social content to purchasable products.
I implemented OAuth, webhook processing, and background jobs, plus custom domains, automatic SSL, CDN image optimization, and Elastic APM for tracing and observability. I also owned CI/CD, automated testing, and production delivery, with a focus on storefront SEO, Core Web Vitals, and reliability.
Monetization Platform for Content Creators
https://hiretheauthor.com/Hire the Author is a platform for creators to sell their time via 1–1 calls, chat subscriptions, and QnAs. I worked as the co-founder and CTO, developing the front-end and back-end applications. The front end is based on Angular, and the back end is based on Node.js. The back end is completely serverless, using AWS Lambda and DynamoDB. Both the front end and back end were deployed on AWS. The application also has integrations with multiple third-party APIs like Stripe, the Places API, Amplitude, etc.
Remote Serverless
https://www.remoteserverless.com/A Next.js-based server-side rendered web application for providing serverless related services and resources. I developed the back- and front-end applications and also took care of the deployment.
Tech stack used:
Front end: React, Next.js, Bootstrap, MUI
Back end: Node.js, AWS Lambda, Amazon DynamoDB
Infrastructure as Code (IaC): Serverless Framework
Deployment: AWS Amplify
Tech stack used:
Front end: React, Next.js, Bootstrap, MUI
Back end: Node.js, AWS Lambda, Amazon DynamoDB
Infrastructure as Code (IaC): Serverless Framework
Deployment: AWS Amplify
Scan and Book Bike
Scan and Book enables a user to book a scooter by scanning the scooter's number plate.
Developed this web application for booking scooters by uploading an image of the number plate. Won second place in the Bounce hackathon for this project
Developed this web application for booking scooters by uploading an image of the number plate. Won second place in the Bounce hackathon for this project
Education
2014 - 2018
Bachelor's Degree in Computer Science
National Institute of Technology, Calicut - Kerala, India
Certifications
MARCH 2022 - MARCH 2025
AWS Certified Solutions Architect - Associate
Amazon Web Services (AWS)
Skills
Libraries/APIs
Node.js, Stripe API, React, REST APIs, Instagram API, Google Maps API, Stripe, Stripe Connect, OpenAI API, Azure Computer Vision API, Amazon Rekognition, AWS Amplify, WhatsApp API
Tools
Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (SNS), Figma, Git, AWS CloudFormation, Postman, Jira, Amazon Elastic Container Service (ECS), GitLab CI/CD, Claude, Codex, Observability Tools, Amazon Cognito, Amazon CloudFront CDN, Terraform, GitHub, Webpack, Adyen Payments, Google Sheets, Claude Code, Amazon Virtual Private Cloud (VPC), Google Analytics, Prisma, Canva
Languages
TypeScript, HTML5, CSS, JavaScript, HTML, Java, CSS3, Python, SQL, GraphQL
Frameworks
Angular, Serverless Framework, Oracle JavaScript Extension Toolkit (JET), Next.js, Tailwind CSS, Flutter, Express.js, Bootstrap, Redux, React Native, Jest, Material UI, Spring
Paradigms
Serverless Architecture, REST, DevOps, Back-end Architecture, Lambda Architecture, API Architecture, Microservices, Agile Software Development, Mobile Development, UI Design, UX Design, Agile, Microservices Architecture, Model Context Protocol (MCP)
Platforms
AWS Lambda, Amazon Web Services (AWS), Google Cloud Platform (GCP), Azure, Docker, Vercel, Blockchain, Amazon EC2, DigitalOcean
Storage
Amazon DynamoDB, Amazon S3 (AWS S3), PostgreSQL, NoSQL, Redis, MongoDB, MySQL, Datadog, Graph Databases, Neo4j
Other
Software Design, Serverless, Back-end Development, API Integration, APIs, Full-stack, Front-end, Front-end Development, Responsive UI, Full-stack Development, User Interface (UI), API Gateways, AWS Cloud Architecture, Pagination, CTO, AWS Certified Solution Architect, AI Tools, Cursor AI, Architecture, Server-side Rendering (SSR), Artificial Intelligence (AI), Large Language Models (LLMs), Software Engineering, AI Agents, Single-page Applications (SPAs), Agentic AI, Software Architecture, Cloud Architecture, Infrastructure as Code (IaC), Component-based Architecture, Design Systems, API Design, Enterprise Architecture, Solution Architecture, Cloud, Startups, System Architecture, Team Leadership, Agentic Workflow Design, eCommerce, Marketplaces, Data Engineering, AI-assisted Development, Stakeholder Management, AI Evaluation, Amplitude, Back-end, Relational Database Services (RDS), CI/CD Pipelines, WebSockets, User Experience (UX), Lambda Functions, Technical Leadership, Meta Ads, OpenAI, Vector Databases, Prometheus, Amazon RDS, Amazon Kinesis, Pinecone, Vite, Razorpay, RAG Architecture, RAG Pipelines, Retrieval-augmented Generation (RAG), AI Architecture, AI Engineering, Multi-agent Systems, Knowledge Graphs, LLM Agents
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