Solidity developer to upgrade and deploy presale vesting contract (test network then main network) - Contract to Hire

We need an experienced Solidity developer to upgrade an existing presale smart contract so that token buyers are forced into vesting (no immediate token delivery). The updated Solidity code is already prepared.

Your job is to:

compile and validate the contract

perform the upgrade and deployment process on a test network

produce the updated application binary interface [ABI]

run a small set of smoke tests (buy, claim)

then repeat the upgrade on the main network

Important: This job is smart contract only. Dashboard and web changes are handled by a separate developer.

What you will do

Review the updated Presale contract (upgradeable proxy pattern using Universal Upgradeable Proxy Standard [UUPS])

Compile and generate the updated application binary interface

Prepare or update deployment and upgrade scripts (Hardhat preferred)

Upgrade on a test network and verify on the block explorer

Configure at least one stage and vesting config and run a smoke test:

buy with one payment method

confirm tokens are recorded as locked

confirm claim works when eligible (or simulate time in a local fork)

Upgrade on the main network and verify on the block explorer

Deliver a short runbook so we can repeat or audit the steps later

Deliverables

Please provide the following at the end of the job:

Proxy address and new implementation address (test network and main network)

Transaction hashes for the upgrade and key configuration calls

Updated application binary interface file (the JSON artifact or ABI array)

The exact deployment and upgrade scripts used

A short “how to deploy and configure” runbook (one page is fine)

Requirements

Strong Solidity experience, including upgradeable contracts

OpenZeppelin upgradeable libraries and access control

Proven experience upgrading and deploying proxy contracts safely

Hardhat and Ethers.js (or Foundry if you prefer, but you must supply clear scripts)

Clear communication and careful execution (this touches main network)

Nice to have

Experience with presale contracts, vesting schedules, and claim logic

Experience writing basic smoke tests for buy and claim flows

Experience with contract verification on common explorers

Apply Now

Apply Now