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Germán – React, Next.js, Typescript, experts in Lemon.io

Germán

From Portugal (UTC+1)flag

Blockchain Engineer|Senior
Full-stack Web Developer|Senior

Germán – React, Next.js, Typescript

Germán is a Senior engineer with 8 years of experience in blockchain, specializing in Ethereum-focused SDKs, smart contract integrations, and full-stack development with React, TypeScript, and Node.js.

He has a background as a Founding engineer, having mentored engineers, participated in technical hiring, and spoken at workshops and conferences. He demonstrates strong system design, database migration, and problem-solving skills, with a focus on building dApp infrastructure and client-side blockchain integrations.

10 years of commercial experience in
Agritech
Asset management
Blockchain
Climate tech
Cryptocurrency
Data analytics
Fintech
Healthtech
Maritime
Open source
Enterprise software
Messaging software
Web3
Web development
Software development
Main technologies
React
8 years
Next.js
3 years
Typescript
8 years
Blockchain
8 years
Ethereum
8 years
Node.js
6 years
web3.js
8 years
Ethers.js
6 years
Additional skills
JavaScript
HardHat
CSS
Jest
Solidity
Material UI
Redux
React Hooks
API
Unit testing
React Hook Form
Integration Testing
React Query
Browser extension
GitHub Actions
GitHub
Git
CI/CD
Docker
Tailwind CSS
Wagmi
Cursor
Claude LLM
Nest.js
PostgreSQL
Zustand
HTML
.NET
C#
Data analysis
D3.js
ClickHouse
Distributed Systems
Google Analytics
Docker Compose
Cloudflare
OAuth
Design system
RPC
Data Modeling
Direct hire
Possible
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Experience Highlights

Founder
Jun 2025 - Feb 20268 months
Project Overview

Side project. It's a data analytics web platform and Ethereum network indexer, providing on-chain interaction metrics for smart contracts and protocols, as well as competitor behavior, to generate insights into usage patterns, loyalty, and retention.

Responsibilities:
  • Architected a full-stack Ethereum analytics platform with custom indexing pipelines and data models in ClickHouse/PostgreSQL.
  • Built the back-end API and interactive dashboard for seamless on-chain data visualization.
  • Created on-chain metrics to support competitor benchmarking, smart contract analysis, and user retention insights.
  • Deployed production infrastructure on Hetzner using Docker containers and GitHub Actions CI/CD.
Project Tech stack:
JavaScript
Typescript
Node.js
PostgreSQL
Cloudflare
ClickHouse
React
React Query
React Hook Form
React Hooks
API
Zustand
Distributed Systems
OAuth
Google Analytics
Tailwind CSS
Design system
CI
CD
Git
GitHub
GitHub Actions
Docker
Docker Compose
Data Modeling
Ethereum
RPC
Blockchain
web3.js
D3.js
Senior Software Engineer
Apr 2022 - May 20253 years 1 month
Project Overview

It's a multisig security platform for on-chain assets in the Ethereum ecosystem, with $50B+ in total value locked and $1T+ in total volume processed.

Responsibilities:
  • Designed and launched the Safe{Core} Account Abstraction SDK supporting 100+ EVM chains and multiple partners.
  • Served as a technical member of the Safe Grants Program committee.
  • Led global workshops on Account Abstraction, created technical docs and demo apps, and coordinated with SDK/API teams.
  • Integrated the Safenet transaction processor network into the Safe{Wallet} web application.
  • Supported external companies building on the Safe ecosystem.
  • Mentored team members on technology stack and business logic.
  • Contributed to hiring and candidate selection processes.
Project Tech stack:
Typescript
JavaScript
React
React Hooks
React Hook Form
React Query
Tailwind CSS
Node.js
Solidity
Wagmi
Ethers.js
web3.js
Unit testing
Integration Testing
Jest
CI
CD
Docker
Git
GitHub
GitHub Actions
Claude LLM
Cursor
PostgreSQL
Nest.js
Senior Software Engineer
Dec 2017 - Apr 20224 years 3 months
Project Overview

It's a Blockchain infrastructure provider focused on creating tools to help expand the utility of the Ethereum ecosystem, having incubated companies such as Safe and CoW Protocol.

Responsibilities:
  • Designed, architected, and implemented the Safe browser extension, integrating an EVM-compatible smart contract wallet into browsers.
  • Built the Contract Proxy Kit and Safe{Core} Account Abstraction SDK.
  • Contributed to the Safe{Wallet} web application implementation.
  • Participated in hiring and candidate selection processes.
Project Tech stack:
Browser extension
React
React Hook Form
React Query
JavaScript
Typescript
Ethers.js
web3.js
Solidity
HardHat
Redux
Material UI
Jest
Blockchain
Ethereum
HTML
CSS
API
Integration Testing
Unit testing
Node.js
React Hooks
CI
CD
Git
GitHub
Docker
GitHub Actions
Software Engineer
Aug 2016 - Dec 20171 year 4 months
Project Overview

Development and manufacture of electronic equipment adapted to the marine environment and focused on smart oceans and sustainable fishing.

Responsibilities:
  • Maintained and expanded the in-house airtime billing system and daily reporting for customers and the tuna fishing fleet.
  • Designed and migrated the airtime billing system to a desktop application.
Project Tech stack:
.NET
C#
PostgreSQL
Academic Intern
Aug 2015 - May 20169 months
Project Overview

Development of advanced genomic software and diagnostic solutions with a leading focus on inherited cardiovascular diseases and personalized medicine.

Responsibilities:
  • Completed Master's final project: automatic generator for estimating survival curves in patients with inherited cardiovascular diseases.
  • Collaborated on the design and implementation of genetic analysis software for studying inherited cardiovascular diseases.
Project Tech stack:
JavaScript
D3.js
.NET
Data analysis
C#
PostgreSQL

Languages

Galician
Advanced
Spanish
Advanced
English
Advanced

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