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