Founding Engineering & Product Team Build Pet360, the First Web3

Remote (Worldwide) • Contract • $50–$150/hr

We are building the first blockchain-based pet ecosystem in Brazil. With 160 million pets and zero blockchain infrastructure today, we see a massive opportunity to transform pet care through Web3 technology.

Our Web2 platform is 75% complete. Now we're building the Web3 layer from scratch — pet NFT passports, vaccine certificate NFTs, smart contract adoptions, and on-chain pet insurance.

Open Positions

1. Founding Blockchain Engineer (Tech Lead)

$100–150/hr • 30+ hrs/week • Founding token allocation

What you'll do:

Own the entire Web3 architecture — from smart contracts to blockchain API layer to frontend integration

Write and deploy Solidity smart contracts (ERC 721, ERC 1155)

Implement upgradeable contract patterns (UUPS) and security best practices

Build the blockchain API layer (NestJS + ethers.js)

Design on-chain data architecture and indexing strategy

Lead and mentor the blockchain engineering team as we grow

You have:

5+ years of software engineering, 3+ years in blockchain

Deep Solidity/EVM expertise — production-grade smart contracts, gas optimization, security audits

Experience with Foundry or Hardhat testing frameworks

Full-stack capabilities across TypeScript/Node.js and React/Next.js

Multi-chain experience (Ethereum, Polygon, Solana) is a plus

2. Solidity Smart Contract Developer

$70–120/hr • 30+ hrs/week

What you'll do:

Write and deploy Solidity smart contracts (ERC 721 for pet passports, ERC 1155 for vaccine certificates)

Implement upgradeable contract patterns (UUPS) for future flexibility

Write comprehensive tests using Foundry or Hardhat

Optimize gas usage and ensure security best practices

You have:

3+ years of software development, 1+ year in Solidity/EVM

Strong understanding of ERC standards and smart contract security

Experience with smart contract testing frameworks (Hardhat, Foundry, Truffle)

Attention to security details and gas optimization

3. Senior Full-Stack Developer or Frontend Developer

$70–100/hr • 30+ hrs/week

What you'll do:

Complete remaining Web2 features (OTP endpoints, appointment status, forms, missing pages)

Build Web3 frontend features (wallet connection using Wagmi + RainbowKit, minting UI for pet NFTs)

Develop blockchain API layer (NestJS + ethers.js)

Work alongside our Solidity developer and backend team

You have:

5+ years of full-stack development

Deep expertise in Next.js, React, TypeScript, and Tailwind CSS

Experience with Node.js, NestJS, or similar backend frameworks

Understanding of Web3 and blockchain concepts

Experience with ethers.js, Wagmi, or similar libraries is a plus

4. Backend API Engineer

$70–100/hr • 30+ hrs/week

What you'll do:

Build the blockchain API layer using NestJS + ethers.js

Design transaction relayer and event indexing infrastructure

Build REST APIs and microservices for Web2 and Web3 integration

Work alongside our Solidity developer and frontend team

You have:

5+ years of backend development

Deep expertise in Node.js, TypeScript, NestJS or Express.js

Experience with PostgreSQL, Redis, and Docker

Understanding of blockchain and Web3 concepts

Experience with ethers.js or web3.js is a plus

Experience with event-driven architectures and message queues (Kafka, RabbitMQ) is a plus

5. Product Designer

$60–90/hr • 20–30+ hrs/week

What you'll do:

Review and refine the existing Web2 UI

Design Web3 user flows (wallet connection, NFT minting, vaccine certificates, insurance dashboards)

Create wireframes, prototypes, and high-fidelity designs

Build and maintain a design system across Web2 and Web3

Conduct user research and usability testing

Work closely with product managers and engineers

You have:

4+ years of product design experience for web and mobile

Strong portfolio showcasing user-centered design process

Proficiency in Figma, Sketch, or Adobe XD

Experience designing dashboards or complex B2C/B2B platforms

Understanding of Web3/wallet UX is a plus

Professional English proficiency

6. Go / Rust Infrastructure Engineer

$90–150/hr • 30+ hrs/week

What you'll do:

Build high-throughput transaction relayer — handle thousands of blockchain transactions per second

Build event indexing engine — process and index blockchain events in real time

Build high-performance data pipelines — collect, process, and store on-chain data efficiently

Design low-latency, high-concurrency systems in Rust or Go

You have:

3+ years of Rust or Go systems programming

Deep understanding of distributed systems, consensus algorithms, and high-performance data structures

Experience with blockchain node infrastructure and RPC integrations

Knowledge of PostgreSQL, Redis, and Kafka is a plus

7. Mobile Engineer (React Native / Kotlin Multiplatform)

$70–100/hr • 30+ hrs/week • Founding token allocation

What you'll do:

Build the mobile app (iOS + Android) from scratch

Integrate wallet connection for pet NFT passports

Connect to our blockchain API layer

Ensure security, performance, and scalability

Design intuitive interfaces for non-crypto-native users in Brazil

You have:

3+ years of mobile development (React Native or Kotlin Multiplatform)

Experience with wallet integration and blockchain concepts

Strong understanding of mobile security and performance optimization

Experience with App Store and Google Play deployment

Experience with Web3 libraries (Web3.js, ethers.js, WalletConnect) is a plus

What We Offer

Fully remote — work from anywhere in the world

Competitive compensation ($50–150/hr based on role)

Founding team token allocation (meaningful stake in the project)

Opportunity to convert to full-time after 2–3 months

20–30+ hours per week (flexible)

Shape architecture and tech stack from day one

Work on a product with real-world impact for 160M pets

Payment Options

Crypto (USDC/USDT on Polygon, Ethereum, or Solana) — fast, low-cost, borderless

Fiat (Wise or PayPal)

Monthly payment cycle with standard invoice submission

Hiring Process

Application & Resume Review – We review your background and experience

Technical Assessment – 2–3 hour take-home task (paid)

Technical Interview – Deep discussion about your approach, architecture decisions, and problem-solving

Offer, NDA & Onboarding – If everything aligns, we extend an offer and get you started

How to Apply

Send your resume and GitHub/LinkedIn profile to:

Subject line: Role you're applying for (e.g., "Founding Blockchain Engineer – Pet360")

Resume/CV (PDF or link)

GitHub and/or LinkedIn profile

Desired hourly rate or salary range

Preferred payment method:

Option

Details

Crypto

USDC, USDT, DAI (on Polygon, Ethereum, or Solana) — or any stablecoin of your preference. Also available in ETH, BTC, or SOL.

Fiat

Wise or PayPal

Example:

Subject: Founding Blockchain Engineer – Pet360

Desired rate: $120–140/hr

Payment: USDC on Polygon

[Attached Resume & GitHub link]

We review applications on a rolling basis and will get back to you within 48 hours.

About Block Sherpa

We are a Web3-native consulting and development firm based in London, helping startups and enterprises build cutting-edge blockchain solutions. We are crypto-native, fully remote, and backed by crypto investors from Brazil and the UK.

https://www.linkedin.com/company/block-sherpa/

We believe in AI-assisted development — we use Cursor as our primary development tool and expect our engineers to leverage AI to ship faster without compromising quality.

Let's build the future of pet care in Brazil together.

Block Sherpa — Web3-native consulting and development