
Duarte Madueño
Verified Expert in Engineering
JavaScript Developer
Lisbon, Portugal
Toptal member since April 15, 2013
Duarte brings structure, clarity, and momentum to engineering teams. He turns ambiguity into organized, predictable systems and translates complex technical topics into clear decisions for business and product stakeholders. Duarte aligns teams, removes friction, and helps engineering groups ship with confidence.
Portfolio
Experience
- JavaScript - 15 years
- Node.js - 8 years
- Architecture - 8 years
- Third-party APIs - 8 years
- MongoDB - 4 years
- Git - 4 years
- Distributed Team Management - 3 years
- Redis - 2 years
Preferred Environment
Git, Visual Studio Code (VS Code), MacOS
The most amazing...
...achievement I have is helping triple the capacity of a web team by setting a proper workflow.
Work Experience
Engineering Lead | Engineering Manager
Weavr
- Led three engineering teams (Web, Mobile, and Node.js) across high-reliability fintech systems.
- Delivered the Embedded Payments Run Project, combining a Node.js back end and a responsive web UX.
- Tripled the Web team’s delivery capacity and reduced the release cycle from two weeks to one hour.
- Introduced a structured ownership model (product, development, QA, and TechOps), improving predictability and quality.
- Maintained high code and testing standards, averaging less than one production bug per month.
- Led hiring, interview design, and performance management processes. Hired four engineers and aligned talent to culture and team needs.
- Navigated team restructuring with data-driven decisions while retaining essential capabilities.
Engineering Lead
Comma Payments (acquired by Weavr)
- Joined as freelancer, converted to full-time due to performance.
- Led back-end architecture refactor from serverless to a Dockerized API and migrated Firebase to MongoDB for improved performance and scalability.
- Established long-term code patterns and a back-end structure.
- Designed hiring processes, technical benchmarks, onboarding flows, and performance review mechanics.
- Collaborated with Product, Banking, and Customer Care teams to deliver bank integrations and resolve critical issues.
- Maintained hands-on back-end development while leading engineering initiatives.
Freelancer | Tech Lead | Senior Engineer
Toptal
- Led multiple projects as Tech Lead and Senior Engineer, mentoring developers and coordinating remote teams.
- Served as a bridge between technical and non-technical stakeholders, defining requirements and risks.
- Drove architecture decisions through clear documentation and diagrams.
- Created a Property Energy Efficiency App (MERN). Brought structure to an underfunded project, optimized energy-saving scripts using real-time building metrics, and improved resource usage and system stability.
- Created an auto dialer service (Node.js, MongoDB, and Twilio), designing call-routing logic that integrated with Stripe and Twilio to automate retries and connect users only when agents were available.
- Refactored a social audio platform’s back end, introduced integrated testing and Redis-based microservices to resolve scaling bottlenecks, and replaced SQL text search with Elasticsearch to boost performance and better align with product goals.
Software Engineer | Senior Developer | R&D Lead
Various Companies
- Built real-time, full-stack systems for telecom, media, and enterprise clients, progressively taking on team lead responsibilities.
- Delivered large-scale web platforms, analytics engines, and OTT applications, collaborating closely with product, design, and engineering.
- Developed multiple eCommerce solutions for different types of industries.
- Replaced a Silverlight-built web solution with an HTML5 and TypeScript one that allowed all customers to access the project without web add-ons.
Experience
Content Enrichment
Technologies: Node.js, MongoDB, RabbitMQ, Socket.IO, JavaScript, HTML, WebSockets, CSS, jQuery
NOS TV
https://nostv.pt/Responsibilities: Team management. Set issues for my team, made sure the team was delivering solutions with quality, held meetings to set project requirements with product and design teams, and kept the project on track with the project management team.
Restaurant Booking Website
Reponsibilities: Create content structure on CMS (CiberSTORE 4.5), development of all website areas and functionalities, and PSD to HTML
Technologies: CiberSTORE 4.5 (Owned by IBT) and VB.NET framework 4.0. SQL, Ajax, JavaScript, CSS 2, HTML4, jQuery, Google apps integration, and Facebook login.
FTP Proxy
https://github.com/DropZone/ftp-proxy-nodeTechnologies: Node.js and RabbitMQ.
eCommerce Solution for Atlassian Marketplace
Toyota One Project
Helped with building and compiling processes. Also presented updates to the client on staging environment.
Technologies: Node.js, JavaScript, MongoDB, jQuery, Grunt, Bower, Skrollr, Sass, Git, Bootstrap
Jira Add-on
Technologies: JavaScript, Angular 1, Atlaskit, Atlassian Components, Webpack
Real-time Comments
The tool had a back-office integrated so that the admin could review each individual comment. Depending on configurations, comments would be accepted or rejected to be published. Also, there was an algorithm responsible for reported comments where if a comment had several reports, it would automatically disappear from every user's page. Each user had the ability to block comments from another specific user in two clicks.
Reponsibilities: Develop and architect all the application, server-side and client-side (front-end and comments manager back office).
Technologies: MongoDB, Node.js, HTML, CSS, JavaScript, jQuery, ORTC and xRTML
File Transfer Monitor
Technologies: C#, ASP.NET MVC 4 (Razor templates), HTML, CSS, JavaScript, jQuery, Ajax, SignalR, RabbitMQ, and MongoDB
Real-time User Statistics
Reponsibilites: Help with feature development and architecture.
Technologies: Redis, Node.js, HTML, CSS, JavaScript, jQuery, ORTC and xRTML (Online Readers/Daily Pageviews/Daily Vistors and +seen in RT)
Caching Framework
Technologies: Couchbase, MongoDB, Redis, SQL, C#, .NET
Advertising Approval Platform
Technologies: C#, ASP.NET MVC 4 (Razor templates), HTML, CSS, JavaScript, jQuery, Ajax, and MongoDB
Clients' Back-office
Technologies: C#, ASP.NET MVC 4 (Razor templates), HTML, CSS, JavaScript, jQuery, Ajax, and MongoDB
eCommerce Websites
Technologies: VB.NET framework 2.0 and 4.0 and C# Framework 4.0. XML, Ajax, JavaScript, jQuery, CSS 2 and 3, HTML 4 and 5, SQL Server 2005 and 2008, IIS 7.0
Education
Level 4 (Equivalent to Bachelor) Degree in Technological Specialization for Software Development
Forino, ENT - New Technologies School - Lisbon, Portugal
Level 3 Degree in Informatic Technologies
Escola Secundária de Fonseca Benevides - Lisbon, Portugal
Skills
Libraries/APIs
Node.js, jQuery, Socket.IO, Entity Framework, Skrollr, SignalR, RequireJS, Google Maps, Facebook API, LINQ, React, React Redux, REST APIs, Twilio API, Jira REST API
Tools
Gulp, Git, Microsoft Visual Studio, Sublime Text, SQL Management Studio, Grunt, GitHub, Bower, RabbitMQ, Atlassian, WebStorm, Mongoose, Jira
Languages
TypeScript, JavaScript, SQL, Visual Basic .NET (VB.NET), C#, CSS, HTML, VB.NET, Sass, XML, CSS3, Less, HTML5, PHP, Python, GraphQL
Frameworks
ASP.NET MVC 4, AngularJS, ASP.NET MVC, ASP.NET, Express.js, React Native, Angular, Bootstrap, ASP.NET MVC 5, Spark, Entity, .NET, Redux
Paradigms
Requirements Analysis, Object-oriented Programming (OOP), REST, Event-driven Programming, Agile, Scrum, Test-driven Development (TDD), Unit Testing, Domain-driven Development, Microservices, Microservices Architecture
Platforms
Visual Studio Code (VS Code), NetBeans, Windows, Amazon Web Services (AWS), Linux, MacOS, Firebase, Docker
Storage
JSON, MongoDB, Microsoft SQL Server, NoSQL, HDFS, Couchbase, Elasticsearch, MySQL, Redis
Other
Full-stack, Algorithms, Teamwork, Team Management, Ajax, APIs, Third-party APIs, Third-party Libraries, Middleware, Sports, Communication, Leadership, eCommerce, Distributed Team Management, Architecture, Lovable, Restaurants & Dining, API Integration, OAuth, User Authentication, Styled-components, SVG, Requirements & Specifications, Windows Communication Foundation (WCF), WebSockets, Cloud, Multithreading, Scaling, Technical Leadership, System Architecture, System Architecture Design, Over-the-top Content (OTT), TV, Search Engine Development, Web Development, Software Development, MERN Stack, Recruitment
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