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 eight years of experience taking platforms from concept to production. Spanning enterprises like Koch Industries and Oracle to building her own startups, she knows how to scale software. Beyond writing code, she designs core back ends, sets up CI/CD pipelines, and manages tech operations. A true full-stack all-rounder, Maria easily navigates heavy infrastructure and intuitive frontends to deliver resilient, high-quality software.
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
- Amazon Web Services (AWS) - 8 years
- React - 8 years
- TypeScript - 8 years
- Full-stack - 8 years
- Node.js - 8 years
- Next.js - 3 years
- OpenAI - 1 year
- Vector Databases - 1 year
Preferred Environment
Amazon Web Services (AWS), Amazon DynamoDB, Node.js, TypeScript, PostgreSQL, OpenAI, Pinecone, React, Next.js
The most amazing...
...thing I've built is a multimodal product search using OpenAI/Pinecone, embedding images and product descriptions to power semantic results and SEO keywords.
Work Experience
Co-founder | CTO
2024 - 2026
Vector Scale Labs
- Led a team of three engineers and oversaw the entire software development process to build and launch VectorScale Labs' two main products, Chatwise and Haulistic, completely from scratch.
- Developed the core of Chatwise, a messaging automation tool for social channels. Built out AI automations that tie directly into Shopify to retrieve real-time product context for accurate replies.
- Engineered the entire front-end and back-end infrastructure for the Haulistic.io eCommerce platform. Developed the seller webapp and dashboard, which now handle live data for two brands with a collective 250,000+ following.
- Made the core technical decisions for the company. Mentored the developers and introduced strict E2E and load testing to keep the codebase completely stable as we scaled up new features.
- Set up and maintained our entire CI/CD pipeline from scratch. Handled daily deployments and technical operations to ensure our live products stayed reliable while shipping new code.
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)
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
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)
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
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
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
Experience
Haulistic - Website Builder Platform Tailored for Instagram Brands
https://haulistic.io/Haulistic is a website builder purpose-built for Instagram brands. I co-founded the product and managed a team of five across engineering, design, and growth. I led product strategy and hands-on development of a Next.js storefront builder and a seller dashboard for catalog, inventory, orders/returns, and analytics. We also built a unified chat workspace to manage Instagram and WhatsApp DMs in one place. On the commerce side, I integrated Instagram APIs to power Shop From Reels, plus Razorpay/PhonePe checkout, custom domains with automatic SSL, and CDN image optimization.
Back-end architecture: Node.js/Express with PostgreSQL/Prisma, background jobs for token refreshes and webhooks, secure OAuth for Instagram, and Elastic APM for tracing/observability. I also drove GTM—tutorials, case studies, and onboarding playbooks—while keeping seller sites SEO-friendly and Core Web Vitals-optimized so brands can go from Instagram grid to a fast, shoppable website in hours.
Back-end architecture: Node.js/Express with PostgreSQL/Prisma, background jobs for token refreshes and webhooks, secure OAuth for Instagram, and Elastic APM for tracing/observability. I also drove GTM—tutorials, case studies, and onboarding playbooks—while keeping seller sites SEO-friendly and Core Web Vitals-optimized so brands can go from Instagram grid to a fast, shoppable website in hours.
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
Automated Insurance Payment System
Developed a blockchain and computer vision-based solution to automate insurance payment flow for farmers.
Key functionalities included extraction of insurance details using scanned images of the registration form and triggering automated payout under disastrous weather conditions using a blockchain smart contract connected to a weather API.
Key functionalities included extraction of insurance details using scanned images of the registration form and triggering automated payout under disastrous weather conditions using a blockchain smart contract connected to a weather API.
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
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
Tools
Amazon Simple Queue Service (SQS), Amazon Simple Notification Service (SNS), Git, AWS CloudFormation, Postman, Jira, Amazon Elastic Container Service (ECS), Amazon Cognito, Amazon CloudFront CDN, Figma, Terraform, GitHub, Webpack, Adyen Payments, Google Sheets, Claude Code, Amazon Virtual Private Cloud (VPC), Google Analytics, Prisma, Canva
Languages
TypeScript, HTML5, CSS, JavaScript, HTML, SQL, GraphQL, Java
Frameworks
Angular, Serverless Framework, Oracle JavaScript Extension Toolkit (JET), Next.js, Express.js, Bootstrap, Redux, Jest, Material UI, Tailwind CSS
Paradigms
Serverless Architecture, REST, DevOps, Back-end Architecture, Lambda Architecture, Agile, Microservices Architecture
Platforms
AWS Lambda, Amazon Web Services (AWS), Docker, Vercel, Blockchain, Amazon EC2, DigitalOcean
Storage
Amazon DynamoDB, Amazon S3 (AWS S3), NoSQL, MongoDB, PostgreSQL, MySQL, 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, Amplitude, Back-end, Relational Database Services (RDS), CI/CD Pipelines, WebSockets, User Experience (UX), Lambda Functions, Technical Leadership, Meta Ads, OpenAI, Vector Databases, Amazon RDS, Amazon Kinesis, Pinecone, Vite, Razorpay, RAG Architecture, RAG Pipelines, Retrieval-augmented Generation (RAG)
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