Dan is available for hire
Hire DanDan Avramescu
Verified Expert in Engineering
Full-stack Developer
Lisbon, Portugal
Toptal member since October 20, 2020
Bio
Dan is a full-stack web developer with a passion for technology, and since 2008, he's been building web projects as a consultant and freelance. He's developed several projects while leading internationally remote technical teams and co-founded and ran an online startup for two years. Dan's expertise includes various languages (JavaScript, PHP, and HTML), libraries/APIs (React and Node.js), platforms (WordPress), site speed optimization, among others.
Portfolio
Lotti AI
OpenAI, Anthropic, Gemini, Railway, Stripe, Postmark, Claude Code, Claude API...
OptAI
TypeScript, AI Agents, Agentic AI, AI Automation, AI Engineering, AI Workflow...
Misstourist.com
Node.js, Next.js, PHP, React, AI Product Management, Product Planning...
Experience
- Software Architecture - 16 years
- JavaScript - 16 years
- Full-stack - 11 years
- React - 5 years
- Node.js - 5 years
- Artificial Intelligence (AI) - 4 years
- AI Automation - 3 years
- AI Agents - 2 years
Work Experience
CTO
2025 - PRESENT
Lotti AI
- Developed an innovative product for a social media SaaS company using AI technologies (coding agents and interactive agents).
- Automated 80% of the software development process, gaining a 5-7x increase in correct software output with a small 3-person team as opposed to a previous 7-person team.
- Transitioned SOP to skills and implemented them into processes that are run by AI agents, having humans do the final assessments only.
Technologies: OpenAI, Anthropic, Gemini, Railway, Stripe, Postmark, Claude Code, Claude API, OpenAI API, Codex, AI Product Management, SaaS, Product Planning, Software as a Service (SaaS), AI Automation, Fractional CTO, Standard Operating Procedures Development, Software Architecture, AI Agents, API Development, Agentic AI, Generative Artificial Intelligence (GenAI), PostgreSQL, Testing, Refactoring, Performance Optimization, Code Review, Claude, Vibe Coding, Training, Back-end, Front-end, Python, AI-assisted Development, Software Engineering, API Management, Google Cloud Platform (GCP), Large Language Models (LLMs), Harness, FastAPI, Solution Architecture, APIs, Amazon Web Services (AWS), Payments, ChatGPT API, AI Integration, AI Tools, AI Workflow, Automation, Integration, Integrations, Reporting, AI Architecture, AI Modeling, AI Product Strategy, B2B, Business Strategy, Data Architecture, Product Strategy, OpenRouter, Payment Gateways, React Router, AI Engineering, Agentic Coding, Web Applications, User Interface (UI), Browser Automation
CTO
2025 - 2026
OptAI
- Led product, architecture, and engineering for AI products that help businesses automate social media with low-friction onboarding, reliable operations, and clear human control.
- Built 4 AI products at OptAI, including Lotti and Huusund, taking them from product definition through architecture, implementation, testing, and production operations.
- Launched Lotti (asklotti.ai), an AI social media platform designed to onboard businesses with minimal friction and automate recurring content with clear human approval points.
- Created Huusund (huusund.ch), a low-friction AI service that helps local businesses establish and maintain a consistent social media presence with minimal ongoing effort.
- Designed multi-tenant TypeScript and Python systems covering authentication, billing, asynchronous AI workflows, provider integrations, monitoring, and production safeguards.
- Established an agentic delivery workflow using Claude Code and Codex, with scoped tickets, isolated worktrees, automated reviews, and human acceptance before release.
- Built an end-to-end conversation test lab that exercised real services and persisted state, uncovering a production routing defect that unit tests had missed.
- Improved CI/CD with change-aware test selection, faster runners, and fewer redundant executions, helping the team validate and ship AI-assisted changes more efficiently.
Technologies: TypeScript, AI Agents, Agentic AI, AI Automation, AI Engineering, AI Workflow, AI Tools, Python, Railway, Amazon Web Services (AWS), Google Cloud Platform (GCP), Cloudflare, AI Architecture, Web Applications, User Interface (UI)
Head of Engineering
2023 - 2025
Misstourist.com
- Grew the business to a 7-figure per year income, within the tourism affiliate industry.
- Automated content publishing and partner interactions.
- Created SOPs for the non-technical team and implemented an automated QA system to oversee their implementation.
Technologies: Node.js, Next.js, PHP, React, AI Product Management, Product Planning, AI Automation, Fractional CTO, Standard Operating Procedures Development, Software Architecture, AI Agents, API Development, OpenAI API, Testing, Refactoring, Code Review, Claude Code, Vibe Coding, Back-end, Front-end, AI-assisted Development, Software Engineering, Codex, API Management, Solution Architecture, APIs, Payments, ChatGPT API, Claude API, AI Integration, AI Tools, AI Workflow, Automation, Integration, Integrations, Reporting, AI Architecture, AI Modeling, B2B, Business Strategy, Data Architecture, Product Strategy, CI/CD Pipelines, OpenRouter, Payment Gateways, React Router, AI Engineering, Agentic Coding, Web Applications, User Interface (UI), Browser Automation
Software Engineer
2023 - 2025
Dan Avramescu Freelance
- Integrated LLMs and LLM APIs for code generation and debugging. What used to take me hours of writing boilerplate React components and Node.js APIs now happens 2-3x faster with AI assistance.
- Started incorporating LLM APIs into real client projects for data processing and analysis tasks. I now use LLM models to extract and categorize information and reduce development and delivery time.
- Became an expert at prompt engineering for development tasks and quality code review of AI-generated solutions.
- Learned to leverage AI for quick MVPs and demos. Using tools like ChatGPT for initial architecture planning, Claude for code review, and various AI APIs for functionality, I can now build working prototypes in days rather than weeks.
- Developed expertise in integrating AI services into web applications. I understand the different LLM APIs, how to handle rate limiting, cost optimization, and building solid systems that handle AI service outages.
Technologies: AI Prompts, Next.js, Node.js, React, Large Language Models (LLMs), Large Language Model Operations (LLMOps), APIs, n8n, Gumroad API, Zapier, ChatGPT, OpenAI, Claude, Gemini, Gemini API, OpenAI API, Anthropic, Cursor AI, AI Agents, Event-driven Architecture, Microservices, Express.js, Docker, API Integration, Data Structures, Database Architecture, Databases, CI/CD Pipelines, Firebase, Content Management Systems (CMS), Strapi, Tailwind CSS, Figma, Vercel, Supabase, Cloudflare, Back-end Architecture, Back-end Development, Agile, Web Development, RESTFul APIs, REST, NoSQL, GitHub, GitHub Actions, AWS IoT, DevOps, AI Product Management, Product Planning, Software as a Service (SaaS), AI Automation, Software Architecture, API Development, Generative Artificial Intelligence (GenAI), PostgreSQL, Testing, Refactoring, Code Review, Claude Code, Consulting, Vibe Coding, Back-end, Front-end, Python, AI-assisted Development, Software Engineering, Codex, API Management, Google Cloud Platform (GCP), Qwen, Harness, Solution Architecture, Amazon Web Services (AWS), Payments, ChatGPT API, Claude API, AI Consulting, AI Integration, AI Tools, AI Workflow, Automation, Integration, Integrations, Reporting, AI Architecture, AI Modeling, AI Product Strategy, Data Architecture, Agentic AI, AI-generated Video, OpenRouter, Payment Gateways, React Router, AI Engineering, Agentic Coding, Web Applications, User Interface (UI), Browser Automation
CTO
2022 - 2024
Grapevine Technologies
- Designed the architecture and created a second supply chain application meant to serve business users who need to perform complex operations, from inventory management to managing orders internally and externally to their clients.
- Grew the team from three to eight developers, hired four testers, and integrated them into the team. Assured Agile development is well implemented, and features are shipped on a 2-week sprint basis.
- Engineered search algorithms that scaled seamlessly from hundreds to tens of thousands of products, architecting back-end solutions that got faster as our product catalog increased.
Technologies: React, Node.js, MongoDB, PostgreSQL, CSS, HTML, Heroku, Git, Compass, Postman, JavaScript, SQL, TypeScript, Next.js, Startups, Artificial Intelligence (AI), CTO, Full-stack Development, Event-driven Architecture, Microservices, Express.js, Docker, API Integration, Agile Software Development, Architecture, Data Structures, Database Architecture, Databases, Technical Leadership, CI/CD Pipelines, Solution Architecture, Security, Stripe, Firebase, Figma, Vercel, Supabase, Cloudflare, Back-end Architecture, Back-end Development, Agile, Web Development, RESTFul APIs, REST, NoSQL, GitHub, GitHub Actions, DevOps, SaaS, Product Planning, Software as a Service (SaaS), Fractional CTO, Standard Operating Procedures Development, Software Architecture, AI Agents, API Development, Testing, Refactoring, Performance Optimization, Code Review, Back-end, Front-end, Software Engineering, API Management, Google Cloud Platform (GCP), APIs, Payments, Automation, Integration, Integrations, B2B, Business Strategy, Data Architecture, Product Strategy, Payment Gateways, React Router, Agentic Coding, Web Applications, User Interface (UI)
Senior Web Developer
2014 - 2023
Freelance Work
- Developed and maintained many websites and web applications while working extensively with publishers to create a great web experience for their readers and give them a technical edge in acquiring SEO traffic.
- Helped my clients increase their monthly visitor count from a few thousand to 400,000 while their sites were under my technical supervision and maintenance.
- Kept my clients' sites up to date with the new developments in web requirements (site speed, technical SEO, and visual design trends).
- Developed and maintained more than 25 web projects.
- Integrated various web services: content/product feeds, automatic SMS notification/authentication services, real-time client communication, and server using Socket.IO/polling.
Technologies: Google SEO, Socket.IO, Site Speed Optimization, Git, JSON, Web Services, CSS, HTML, WordPress, Drupal, Node.js, React, JavaScript, React Redux, REST APIs, PhpStorm, Postman, Operating Systems, XML Web Services, SCSS, jQuery, Software Architecture, SQL, TypeScript, Startups, Artificial Intelligence (AI), Model Context Protocol (MCP), Full-stack Development, ChatGPT, Large Language Model Operations (LLMOps), Large Language Models (LLMs), Event-driven Architecture, Microservices, Express.js, Docker, API Integration, Architecture, Data Structures, Database Architecture, Databases, CI/CD Pipelines, Solution Architecture, Security, Content Management Systems (CMS), Figma, Vercel, Cloudflare, Back-end Architecture, Back-end Development, Agile, Web Development, RESTFul APIs, REST, NoSQL, GitHub, GitHub Actions, DevOps, API Development, Testing, Refactoring, Performance Optimization, Code Review, Back-end, Front-end, Software Engineering, API Management, APIs, Payments, Automation, Integration, Integrations, Reporting, Data Architecture, Payment Gateways, Web Applications, User Interface (UI)
JavaScript Engineer
2020 - 2021
Freelance
- Participated in improving an app that offers an online theatrical experience with interactive participation of the viewers.
- Ensured that certain visual and audio tracks were synchronized for all users, regardless of location, and showed the start time.
- Designed an algorithm that allows users with connection issues to resume the theatrical experience at an opportune time.
Technologies: JavaScript, Twilio API, Ruby on Rails (RoR), HTML, Ruby, Amazon S3 (AWS S3), Amazon Web Services (AWS), Express.js, API Integration, Data Structures, Databases, Security, Figma, Agile, Web Development, RESTFul APIs, REST, NoSQL, GitHub, Software Architecture, Refactoring, Back-end, Front-end, Software Engineering, Solution Architecture, APIs, Integration, Integrations, CI/CD Pipelines, Payment Gateways, Web Applications, User Interface (UI)
CTO
2017 - 2020
Tradunity
- Created a startup together with a business partner in the financial products sphere.
- Coordinated the team and grew it from two to eight people while having both technical and non-technical employees.
- Created and maintained the code for our community website and integrated various services into it using the Telegram Bot API, Discord Bots API, Twilio, Zendesk, Mailchimp, and so on.
- Wore all the hats in the company, from technical development, HR responsibilities, partner relationships to creating and coordinating the marketing campaigns, and managing our finances.
Technologies: PHP, SCSS, CSS, HTML, JavaScript, Node.js, Twilio, Telegram Bots, Discord, Google Tag Manager API, Google Analytics API, Tracking, Zendesk API, PhpStorm, Postman, XML Web Services, jQuery, SQL, Startups, CTO, Full-stack Development, Agile Software Development, Architecture, Data Structures, Database Architecture, Databases, Technical Leadership, Security, Figma, Back-end Development, Agile, Web Development, RESTFul APIs, REST, GitHub, SaaS, Fractional CTO, Software Architecture, Refactoring, Training, Back-end, Front-end, Software Engineering, API Management, Solution Architecture, APIs, Payments, Automation, Integration, Integrations, Reporting, Business Strategy, Data Architecture, CI/CD Pipelines, Payment Gateways, Web Applications, User Interface (UI)
Senior Web Development Consultant
2014 - 2017
Altelog
- Stepped up to working as a consultant within top tier French companies and French government institutes.
- Integrated the front-end landing pages with high conversion rates for a Drupal 7 application. The client was Cellfish Media, a fast-paced mobile online marketing company.
- Led a team of developers to create the front-end themes and the back end of two government websites in Drupal 7.
- Served as the lead developer for a startup financed by Engie called Green Channel—integrating clients via Salesforce and creating the front-end theme in a Drupal 7 application.
Technologies: Gulp, Stylus, SCSS, CSS, HTML, JavaScript, PHP, Drupal, Affiliate Tracking, PhpStorm, Postman, XML Web Services, jQuery, SQL, Agile Software Development, Data Structures, Databases, Technical Leadership, Security, Content Management Systems (CMS), Figma, Back-end Development, Agile, Web Development, NoSQL, GitHub, Software Architecture, Refactoring, Consulting, Back-end, Front-end, Software Engineering, Solution Architecture, APIs, Payments, Automation, Integration, Integrations, Data Architecture, Payment Gateways, Web Applications, User Interface (UI)
Web Development Consultant
2013 - 2014
Algo-Expert
- Trained my colleagues in Drupal 7 and taught them the differences between Drupal 6 and 7.
- Worked as a consultant while being based in Paris.
- Maintained 2 Drupal applications for clients in Paris.
Technologies: CSS, HTML, JavaScript, PHP, Full-stack, PhpStorm, XML Web Services, SCSS, jQuery, SQL, Data Structures, Databases, Content Management Systems (CMS), Back-end Development, Web Development, GitHub, Software Architecture, Refactoring, Consulting, Front-end, Software Engineering, Integration, Integrations, Web Applications, User Interface (UI)
Web Developer
2012 - 2013
Cybervision
- Maintained and evolved several client websites in Drupal 6/7 and Joomla.
- Tracked and fixed bugs in Redmine and Jira and created workflows for client feedback and bug resolution.
- Participated in client briefs, contract negotiation, requirements analysis, and offer creation.
Technologies: Joomla, Drupal 7, Drupal 6, CSS, HTML, JavaScript, PHP, Full-stack, XML Web Services, jQuery, SQL, Data Structures, Databases, Back-end Development, Web Development, Software Architecture, Refactoring, Training, Front-end, Software Engineering, Integration, Integrations, Web Applications, User Interface (UI)
Web Developer
2008 - 2010
Uniway
- Developed two websites in Drupal 6 for a steel company and a news outlet in Belgium.
- Created the themes that adhered to Drupal 6 standards at that time.
- Integrated a web service that sent and received XML data. This was 2008, so quite complex for its time.
Technologies: Drupal 6, HTML, CSS, JavaScript, PHP, Full-stack, XML Web Services, jQuery, SQL, Java, Data Structures, Databases, Back-end Development, Web Development, Software Architecture, Front-end, Software Engineering, Integration, Integrations, Web Applications
Project History
Grapevine ERP App
A React/Node.js/MongoDB-based app that allows companies to manage their stocks across multiple warehouses, add and manage client contacts, and create internal and external orders with several payment types.
React Administration UI and JavaScript Show Runner for Online Theatrical Experiences
AnyOneThing creates online theatrical experiences that often get the viewer to participate in the play through his microphone and/or camera. I was tasked with creating an administrative UI with React, which interfaces the back-end API (written in Ruby on Rails) and facilitates administrators to edit the sequences of scenes and theatrical cues (videos, audios, images, and sounds).
Moreover, I created a box office application (also in React) and optimized and evolved the showrunner to work across browsers and offer a better overall experience.
Moreover, I created a box office application (also in React) and optimized and evolved the showrunner to work across browsers and offer a better overall experience.
Tradunity
I was part of a two-founder team of Tradunity: a bootstrapped startup. Our goal was to help beginner traders find success in the financial markets.
I was responsible for technical development and leading the technical team as we grew. I also created the original app and integrated it with all the vital services we needed to create a thriving community.
As our team grew to eight people, so did my responsibilities. We created and executed a very efficient product and promotion strategy, which led to great results. Tradunity has turned a profit from the first month up until the beginning of 2020. The project was closed at the beginning of 2020.
I was responsible for technical development and leading the technical team as we grew. I also created the original app and integrated it with all the vital services we needed to create a thriving community.
As our team grew to eight people, so did my responsibilities. We created and executed a very efficient product and promotion strategy, which led to great results. Tradunity has turned a profit from the first month up until the beginning of 2020. The project was closed at the beginning of 2020.
ClassRoomQ | Node.js and React App
https://classroomq.comClassRoomQ is a Node.js and React app that allows students and teachers in virtual classrooms to interact with each other in a structured way. There were two authorization levels. The authentication had to be done through a middleware that could identify users who were already logged in to a WordPress application. The Node.js and React interaction was done through WebSockets rather than an API to facilitate the two-way interaction between authenticated and anonymous users.
Education
2010 - 2012
Master's Degree in Computer Science
Technical University of Delft - Delft, The Netherlands
2006 - 2010
Bachelor's Degree in Computer Science
Politechnics University of Bucharest - Bucharest, Romania
Skills
Libraries/APIs
React, Node.js, jQuery, REST APIs, Claude API, API Development, React Router, React Redux, Telegram Messenger API, OpenAI API, Socket.IO, Telegram Bot API, Twilio API, Antd, Google Tag Manager API, Google Analytics API, Zendesk API, Gumroad API, Stripe
Tools
Git, PhpStorm, JSX, ChatGPT, Claude, GitHub, Claude Code, Codex, Postman, Google Analytics, AI Prompts, Figma, Stylus, Gulp, Subversion (SVN), Mailchimp, LearnDash, n8n, Zapier
Languages
JavaScript, PHP, CSS, HTML, SQL, TypeScript, Python, C, C++, SCSS, Java, Ruby
Frameworks
Express.js, Next.js, Redux, Tailwind CSS, Compass, Ruby on Rails (RoR)
Paradigms
Event-driven Architecture, Microservices, Agile Software Development, Back-end Architecture, Agile, REST, Refactoring, Automation, DevOps, Testing, B2B, Waterfall Development, Model Context Protocol (MCP)
Platforms
WordPress, Amazon Web Services (AWS), Vercel, Google Cloud Platform (GCP), Docker, Firebase, AWS IoT, Harness, Visual Studio Code (VS Code), Drupal 6, Drupal 7, Joomla, Drupal, Zendesk, Twilio, Heroku
Storage
JSON, PostgreSQL, Database Architecture, Databases, NoSQL, MongoDB, MySQL, Amazon S3 (AWS S3)
Other
Site Speed Optimization, Full-stack, Back-end, APIs, Front-end, Artificial Intelligence (AI), Startups, CTO, Full-stack Development, Large Language Models (LLMs), Gemini, Cursor AI, AI Agents, API Integration, Architecture, Data Structures, Technical Leadership, CI/CD Pipelines, Solution Architecture, Content Management Systems (CMS), Back-end Development, Web Development, RESTFul APIs, AI Product Management, Product Planning, AI Automation, Fractional CTO, Standard Operating Procedures Development, Agentic AI, Consulting, Vibe Coding, AI-assisted Development, Software Engineering, API Management, AI Consulting, AI Integration, AI Tools, AI Workflow, Integration, Integrations, Reporting, AI Architecture, AI Modeling, AI Product Strategy, Data Architecture, OpenRouter, Payment Gateways, AI Engineering, Agentic Coding, Web Applications, User Interface (UI), Web Services, Google SEO, Axios, OpenAI, ChatGPT API, ChatGPT Prompts, Prompt Engineering, Software Architecture, Large Language Model Operations (LLMOps), Security, Strapi, Supabase, Cloudflare, GitHub Actions, SaaS, Software as a Service (SaaS), Generative Artificial Intelligence (GenAI), Code Review, Training, Qwen, FastAPI, Payments, Business Strategy, Product Strategy, AI-generated Video, Browser Automation, Operating Systems, XML Web Services, UML Diagrams, Wireless Sensor Networks, Discord Bots, Affiliate Tracking, Google Tag Manager, Computer Science, WebSockets, EMCAScript (ES), Telegram Bots, Discord, Tracking, Gemini API, Anthropic, Railway, Postmark, Performance Optimization
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