Daniel Dudas
Verified Expert in Engineering
Full-stack Developer
Cluj-Napoca, Cluj County, Romania
Toptal member since May 21, 2017
Daniel is a senior full-stack engineer with 15+ years of experience building and scaling web and mobile applications used by over one million users. He specializes in Node.js, AWS, React, and React Native, focusing on performance optimization, scalable APIs, and production-ready architectures that support real growth.
Portfolio
Experience
- MongoDB - 11 years
- Amazon Web Services (AWS) - 10 years
- Node.js - 10 years
- React Native - 6 years
- TypeScript - 6 years
- React - 4 years
- PostgreSQL - 4 years
- Artificial Intelligence (AI) - 3 years
Work Experience
Lead Full-stack Developer
Vetano
- Led the technical direction and day-to-day execution of a cross-functional engineering team, making architectural and product-driven technical decisions.
- Designed and built a scalable serverless back end on AWS using CDK, PostgreSQL, Redis, and Amazon S3 to support a growing mobile user base.
- Developed and maintained a React Native mobile application using Expo, delivering frequent production releases with a strong focus on stability and UX.
- Implemented real-time and event-driven features using managed services, supporting responsive user interactions at scale.
- Integrated multiple 3rd-party services, including authentication, analytics, subscriptions, and user communication, to accelerate product delivery.
- Improved performance, reliability, and observability through logging, monitoring, and analytics tooling across front-end and back-end systems.
- Collaborated closely with product and stakeholders, translating business requirements into scalable, maintainable technical solutions.
CTO
Live AI Ecosystem
- Designed the architecture for back-end, mobile, and web applications, managing the entire development lifecycle (development, testing, and deployment) and team collaboration using Jira, Slack, and GitHub.
- Developed the complete architecture for a complex marketplace platform, encompassing multi-seller management, diverse payment options, payouts, and integration with multiple logistics providers.
- Integrated multiple payment gateways, including Stripe, Apple Pay, Afterpay, and PayPal, across React Native (front-end) and Node.js (back-end) applications.
- Engineered a system for dynamically blending live and recorded video content (clips) within a personalized feed optimized based on user preferences and past viewing behavior.
- Led the interview process for new team members, provided ongoing mentorship and management to the development team, and fostered collaborative relationships with key stakeholders, including the client.
- Played a key role in defining the technology stack, strategically selecting and integrating tools to optimize development processes, and focusing on seamlessly incorporating Figma designs and concepts.
Software Engineer
Tapptitude
- Developed scalable and performant APIs with Node.js, Express.js, and MongoDB, incorporating rigorous load testing to identify potential bottlenecks and implementing proactive monitoring of live servers to prevent performance issues.
- Integrated various payment solutions, including Stripe, PayPal, MobilePay, and other popular providers.
- Configured servers, deployed apps to production, and confirmed everything worked on the production side.
- Architected web apps using Angular, Material, Bootstrap, and custom-made CSS.
- Built APIs, web, and admin areas using Laravel and custom-made frameworks.
- Optimized heavily used APIs to improve performance and scalability. Implemented automated distributed load testing to proactively identify bottlenecks and ensure responsiveness under high traffic.
- Interviewed and evaluated potential candidates for open team positions.
Software Engineer
Resume-Library
- Built the mobile app for Android and iOS using PhoneGap and Angular 2, which connects to our API using Basic Auth. Built the app from scratch and worked with a designer on this project.
- Integrated a payment system with recurring and other features.
- Architected an event system for logging and reading all events quickly using Cassandra.
- Created a session management system to be used on both web and mobile apps.
- Translated many parts of the website from Perl to PHP using CodeIgniter.
Software Engineer (PHP)
Zonga & Trilulilu
- Built and optimized back-end APIs powering music and video streaming platforms serving a large national user base across web, mobile, and TV clients.
- Implemented and maintained payment systems (card, SMS, PayPal, vouchers) supporting subscription-based monetization for a Spotify-like music service.
- Developed real-time features, including live events and chat, enabling high user engagement on a YouTube-like media platform.
- Improved application performance and reliability through caching, database optimization, and API tuning in high-traffic production environments.
Experience
AI Image Detection Model Training and Use in React Native Mobile App
B2B Payment Platform
I built the iOS, Android, and web front end from scratch using Expo with React Native. I used the same code for mobile and web, making minor adjustments where needed.
On the back-end side, I improved and updated the current Node.js implementation with Express.js and PostgreSQL. I also added more TypeScript types, improved the database connection, and added more APIs. External links were implemented with different payment providers, such as Dwolla for managing payments, Checkissuing for virtual and physical checks, Plaid for connecting bank accounts, and others.
Additionally, I implemented an OCR system to scan the invoices automatically and added a bulk upload system that used OCR to send invoices to the right businesses.
I worked closely with the CEO and took decisions on implementation paths.
Investment Portal for Portfolio Management System
Meridix | Sports Score Game Tracker
https://www.meridix.com/Presentation Website for an Architecture Company in London
Wizz Air Search and Price Alert
Chrome Browser Extension in Angular
I was the only developer on the front-end side (browser extension) and deployed to the Chrome store, but it was built to support other browsers if needed.
TacticalbeT | Sports Betting Tips, Mobile App, APIs, and Admin Dashboard
My Smoothies
Education
Master's Degree in Computer Engineering
Babes-Bolyai University - Cluj-Napoca, Romania
Bachelor's Degree in Computer Engineering
Babes-Bolyai University - Cluj-Napoca, Romania
Certifications
Toptal Angular Academy
Toptal
Skills
Libraries/APIs
React Navigation, REST APIs, jQuery, SendGrid API, Node.js, Redis Queue, Socket.IO, React, React Native for Web, Pusher, Back-end APIs, MobX, Google Maps API, Google Maps, Google Calendar API, Google API, Facebook API, Facebook SDK, Mailchimp API, Mandrill API, Twilio API, Google Location API, Google Places API, OpenAI API, Stripe, Stripe API, Highcharts, Lodash, Moment.js, Dwolla API, Plaid API, Camera API, Avalara Tax API, PayPal API, Amazon Rekognition
Tools
Git, Bitbucket, PhpStorm, Postman, NPM, Composer, Mongoose, WebStorm, Expo, Slack, NGINX, Firebase Cloud Messaging (FCM), Amazon CloudFront CDN, Figma, Jira, Amazon Simple Email Service (SES), Branch.io, SendGrid, Google Places SDK, You Only Look Once (YOLO), Open Neural Network Exchange (ONNX), AWS Cloud Development Kit (CDK), TestFlight, Subversion (SVN), Apache, Amazon Simple Queue Service (SQS), iTunes Connect, GitHub, Angular CLI, Apache Solr, Sublime Text, Expo.io, Plaid, Apple Push Notifications, WebView, OneSignal, Afterpay, Amazon CloudWatch, Amazon CloudFront, Notion, AWS CloudFormation, Amazon Textract, Google Analytics
Languages
CSS, TypeScript, JavaScript, PHP, HTML, SQL, HTML5, PHP 7, Sass, CSS3, Go, SCSS, GraphQL, Python, Python 3
Frameworks
Express.js, Angular, Bootstrap, Laravel, React Native, Next.js, i18next, Swagger, PHPUnit, CodeIgniter, Redux, Dropzone.js, Smarty, AngularJS, PhoneGap, Jest, Tailwind CSS, tRPC
Paradigms
REST, Mobile Development, App Development, Agile Software Development, Microservices, Automation, Scrum, Agile, Responsive, DevOps, Kanban, Unit Testing, Load Testing, Web App Design
Platforms
Heroku, AWS Elastic Beanstalk, Mobile, Web, MacOS, Amazon Web Services (AWS), Mandrill, Amazon EC2, Twilio, Vercel, Clerk, Mixpanel, RevenueCat, iOS, Docker, New Relic, Android, Linux, DigitalOcean, AWS Lambda, Firebase, Azure, WooCommerce, Algolia, LiveKit, WordPress, Ably
Storage
NoSQL, Amazon S3 (AWS S3), MongoDB, MySQL, Redis, JSON, Databases, Relational Databases, PostgreSQL, Memcached, Redis Cache, Amazon DynamoDB, Cassandra, Firebase Realtime Database
Other
APIs, Redis Clusters, Web Crawlers, API Design, Database Schema Design, Live Chat, NativeBase, Full-stack, Cross-platform App Development, IT Consulting, Cloud, Computer Engineering, Login Screens, Session Handling, WebSockets, Mobile App Development, Login & Registration, Mobile Apps, Back-end, Atlas, Hybrid Apps, gluestack, Tailwind UI, API Integration, Web Development, Back-end Development, Card Payments, Front-end Development, Full-stack Development, Web App Development, Front-end, Google Sign-in, Mobile Applications, Web & Mobile Applications, React Native Navigation, Artificial Intelligence (AI), Leadership, Team Leadership, Startups, Team Management, User Experience (UX), Software Architecture, Software Design, Third-party APIs, Automation Software, Google Material Design, Amazon Route 53, Responsive Web Apps, Webhooks, Web Scraping, Push Notifications, In-app Purchases, Responsive UI, Chrome Extensions, Scraping, Serverless, Amazon RDS, Payment APIs, Online Payments, HTML Email, SMS, Data Scraping, AWS DevOps, AWS Elemental MediaConvert, React Native Reanimated, Lottie, Image Recognition, Stripe Terminal, Apple Pay, Google Play Console, SVG, Machine Learning, ONNX Runtime, Object Detection, RTL, Data Labeling, CTO, DNS, DNS Configuration, User Interface (UI), Fractional CTO, Project Leadership, System Architecture, API Gateways, AWS Secrets Manager, Personas, LogRocket, App Store Connect, Intercom, OpenAI, Maps, App Store, Payment Processing, Payment Gateways, OAuth, Agentic Coding, AI-assisted Development, Data Engineering, Web UI, DI, Content Management Systems (CMS), Interviews, Apache Cassandra, Cordova, eCommerce, Google Play Store, Content Delivery Networks (CDN), Integration Testing, i18n, Translation, Charts, Tables, Issue Tracking, FontAwesome, Themes, Extensions, TypeORM, Optical Character Recognition (OCR), Veryfi, CSV, CSV Export, PDF, Email, Contact Sharing, Digital Signatures, Material Design, PayPal, Cloudflare, HTTP Live Streaming (HLS), Streaming, CSV Import, CSV File Processing, Image Compression, BullMQ, Video Livestreaming, Data Augmentation, Google Colaboratory (Colab), Optimization, Query Optimization, Cursor AI, Technical Leadership, Amazon EventBridge, Virtual Private Cloud (VPC), Amazon Pinpoint, QR Codes, AI Chatbots, Supabase, Financial APIs
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