Blockchain Developer

Humb Global Healthtech India; Pune District; On-site; INR 1,200,000 - 1,800,000; Full time

Job summary

Humb Global Healthtech India is seeking a blockchain engineer to build and maintain a multi-chain wallet infrastructure, including ERC-3643 tokenized assets. You will implement deposit/sweep flows, integrate providers like Tatum, and develop smart contracts including ERC-20/721 and ERC-3643.

Emphasis on security, idempotency and reliable money movement. You will work with Node.js, Solidity, and web3 libraries across EVM and non-EVM chains, ensuring robust transaction handling and compliance

Qualifications

• 3–4 years building production blockchain applications.
• Strong Node.js/JavaScript with Express and MongoDB.
• Hands-on with web3.js or ethers.js and at least one non-EVM chain (Bitcoin/Tron/Solana).
• Solidity: read, write and test contracts including ERC-20/721 and ERC-3643 tokens.

Responsibilities

• Develop and maintain wallet services across EVM chains (Ethereum, BNB Chain, Polygon, Base), Bitcoin, Tron and Solana.
• Implement address generation, deposit detection, sweeping, gas provisioning and withdrawal broadcasting.
• Integrate node/infrastructure providers (Tatum, RPC endpoints) and handle webhook-driven transaction events.
• Write and integrate smart contracts ERC-20 / BEP-20, ERC-3643 (T-REX) tokens, staking, token sale, plus tests and deployment scripts.
• Implement ERC-3643 compliance flows: identity registry and ONCHAINID onboarding, claim issuers/topics, transfer-restriction and compliance modules, agent/owner roles, and forced-transfer/freeze/recovery operations.
• Ensure idempotency and correctness on all money paths, no double-spends, no lost deposits.
• Handle key management, signing flows and secure secret storage.
• Debug on-chain issues: stuck transactions, nonce conflicts, failed receipts, reorgs, and rejected compliance transfers.

Skills

Node.js

JavaScript

Express

MongoDB

web3.js

ethers.js

Solidity

ERC-20/721/ERC-3643

REST APIs

Redis

Git

CI/CD

Docker

AWS/Azure

Tools

Tatum

Alchemy

Docker

Azure

AWS

Job description

Role

Build and maintain the multi-chain wallet, deposit, withdrawal and sweep infrastructure, including permissioned (ERC-3643) tokenized assets.

Responsibilities

• Develop and maintain wallet services across EVM chains (Ethereum, BNB Chain, Polygon, Base), Bitcoin, Tron and Solana.
• Implement address generation, deposit detection, sweeping, gas provisioning and withdrawal broadcasting.
• Integrate node/infrastructure providers (Tatum, RPC endpoints) and handle webhook-driven transaction events.
• Write and integrate smart contracts ERC-20 / BEP-20, ERC-3643 (T-REX) permissioned tokens, staking, token sale, plus tests and deployment scripts.
• Implement ERC-3643 compliance flows: identity registry and ONCHAINID onboarding, claim issuers/topics, transfer-restriction and compliance modules, agent/owner roles, and forced-transfer/freeze/recovery operations.
• Ensure idempotency and correctness on all money paths, no double-spends, no lost deposits.
• Handle key management, signing flows and secure secret storage.
• Debug on-chain issues: stuck transactions, nonce conflicts, failed receipts, reorgs, and rejected compliance transfers.

Required

• 3-4 years building production blockchain applications.
• Strong Node.js/JavaScript; solid Express and MongoDB.
• Hands-on with web3.js or ethers.js, plus at least one non-EVM chain (Bitcoin, Tron or Solana).
• Solidity: can read, write and test contracts.
• Working knowledge of token standards, ERC-20/721 and ERC-3643 permissioned/security tokens (identity, claims, transfer compliance).
• Practical grasp of transaction lifecycle, gas, nonces, confirmations, receipts.
• Comfortable with REST APIs, webhooks and async job processing (Redis, queues).
• Git, code review, environment-based deployments.

Nice to have

• Shipped an ERC-3643 / T-REX deployment or other RWA / security-token platform.
• Crypto exchange or fintech background.
• Exposure to custodial wallet architecture, HD wallets or MPC/HSM signing.
• Experience with Tatum, Fireblocks, Alchemy or similar.
• Docker, CI/CD, Azure or AWS.
• Awareness of AML/KYT and compliance tooling.

You should apply if

You have shipped real on-chain money movement, understand why a compliant token can reject a transfer, and can debug a failed withdrawal end-to-end without hand-holding.