Introduction
Overview.
Frontend Developer
React Native Developer
Web3 & DeFi Developer
UI/UX Focused
What I have done so far
Work Experience.
Frontend Developer
HoudiniSwap
- Built a Manifest V3 Chrome extension — featuring a side-panel swap UI with JWT-secured API integration — extending the capabilities of the main platform directly in the browser.
- Engineered a payment-link system enabling users to generate shareable, pre-configured swap links for seamless one-click transactions.
- Developed an embeddable widget playground allowing third-party sites to integrate HoudiniSwap's swap UI directly into their pages.
- Implemented GraphQL subscriptions for real-time quoting and live order tracking across multi-chain wallets (EVM, Solana, Bitcoin, Tron, Sui, TON).
- Developed smart contract interaction layers for token approval flows and transaction signing.
Frontend Developer
Unizen
- Analyzed and implemented high-end code solutions following best architectural practices and component structural development.
- Built user-friendly Web3 and DeFi interfaces using Next.js, Ether.js, Wagmi, and Reown (AppKit/WalletConnect).
- Implemented smooth UI/UX animations with Framer Motion and actively contributed to product design decisions.
- Worked with Zustand for state management and Tailwind CSS for scalable, responsive styling.
React.js Frontend Developer
Tryg / Tata Consultancy Services
- Developed a digital pregnancy product for Tryg (a major Scandinavian insurance company), deployed across 10+ subsidiaries and driving 10% customer growth.
- Leveraged React, TypeScript, and React Native to build high-quality, user-friendly web applications and embeddable widgets.
- Actively contributed to product design decisions, ensuring intuitive and efficient user interfaces.
- Implemented testing methodologies (Jest, Cypress) to ensure optimal performance and reliability.
- Utilized CSS3, Styled Components, and Material UI for fully responsive layouts.
Full-stack Developer
Freelance
- Planned and engineered RESTful web services to manipulate dynamic datasets using React and Ruby on Rails.
- Built landing pages, dashboards, and online applications, producing both visuals and content to meet project specifications.
- Conducted unit testing to deliver optimal browser functionality and employed best-practice coding standards.
- Trained and supervised junior team members on ongoing full-stack projects.
My work
Projects.
Following projects showcases my skills and experience through real-world examples of my work. Each project is briefly described with links to code repositories and live demos in it. It reflects my ability to solve complex problems, work with different technologies, and manage projects effectively.
El patron AI assistant
Web-based platform and Chromium extension to allow users to scan repositories for malicious code and vulnerabilities using AI. The platform provides a user-friendly interface for developers to upload their code and receive detailed reports on potential security issues, along with recommendations for remediation. It also provides an overall AI assitant focused on security vulnerabilities and what to look for
#Next.js
#Supabase
#BYOK Encryption
#Gemini AI
#Chromium Extension
Movie Database
Web application that enables users to search for movies, view details, and manage their watchlist.
#React
#restapi
#Tailwind CSS
Wizard Runner (Phaser Game)
The wizard runner is an endless runner game where players run over some platforms and jump from one platform to another. The burning fires are presented as obstacles that must be dodged to continue the game. Coins can be collected to increase the score and the game ends once the user falls down the platform or gets burned by the fire.
#javascript
#phaser
#webpack
What others say
Testimonials.
"
I had the pleasure of working with Sergio at HoudiniSwap, and I can confidently say he's both a strong engineer and a great teammate. He brings solid…
@ Halil Atilla
Senior Frontend Developer at HoudiniSwap
"
Sergio is deeply passionate about his work and is a fantastic collaborator. When working with him, you can always rely on his support, being highly de…
@ Ganesh Singh
UI Engineer II at Cleartrip (Flipkart Group)
"
Sergio is a fantastic developer and is a pleasure to work with. We have spent a lot of time in the same team together while enrolled at a software dev…
@ Ryel Banfield
Founder & Lead Developer at RCB Software
Get in touch