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Blockchain and DeFi

DeFi protocols engineered, audited and shipped to mainnet.

Netixsol designs, builds and audits DeFi protocols, exchanges and smart contracts. We have worked on 25+ blockchains and take each build from threat model to mainnet.

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Deployment record

What each record lists
Protocol
Name and released version
Network
Every chain it runs on, mainnet and testnet
Contract
Each address, with source verified on the explorer
Tests
Unit, fuzz and invariant test counts
Audit
Who reviewed it, when, and how each finding was resolved
Admin
Who holds admin powers: multisig signers, timelock, roles
Status
Live since date, and where to watch it

Is this the right fit?

A good fit

  • You are launching a DEX, lending market, staking system or token, and real funds will sit in the contracts.
  • You need contracts tested and prepared for an independent audit before mainnet.
  • You want one team for the contracts, the indexing and the app your users touch.
  • You have contracts live already and need a review before an upgrade or a launch.

Not a fit

  • You want a token live in days, with no tests and no review.
  • You want advice on token price, listings or investment. We build and review software.
  • You need a legal opinion on your token. We work with your counsel, not in place of it.

What we build

  1. Decentralized exchangesAMM liquidity, contracts for matching and settlement, and the trading interface.
  2. DeFi protocolsLending and borrowing markets, yield systems and cross-chain bridges.
  3. Smart contractsSolidity contracts designed, tested and deployed for your use case.
  4. Staking and liquid stakingStaking and yield contracts with clear reward accounting, emissions and vesting.
  5. Asset tokenizationReal-world assets on-chain, with ownership records and fractional transfers.
  6. Crypto walletsExchange wallets for deposits, withdrawals and integrated trading.
  7. NFT marketplacesMinting, auctions and royalties, with the contracts that govern ownership.
  8. dAppsDecentralized apps with wallet sign-in, crypto and fiat payments, and exchange integration.
  9. Smart contract auditsReviews that find vulnerabilities, logic bugs and unintended behavior before launch.

How it fits together

  1. People

    • UsersMetaMask or Trust Wallet
    • Your operatorsAdmin roles you control

  2. Apps

    • React web app
    • Admin console

  3. Data

    • SubgraphsPositions, history and analytics
    • IPFS and PostgreSQL

  4. Contracts

    • Smart contractsSolidity and OpenZeppelin, tested with Hardhat and Foundry
    • ChainsEthereum, Polygon, Arbitrum, Optimism, BNB Smart Chain, Tron
How a protocol fits together

  1. Invariants before code

    We write down what must always hold, such as solvency or total supply. Tests then try to break each one.

  2. Admin powers in the open

    We agree with you who can upgrade, pause or change parameters. We recommend putting those powers behind a multisig and a timelock, and we document each one.

  3. Price feeds chosen per asset

    Each oracle is picked for the asset's liquidity, with staleness and deviation checks and a fallback.

  4. Indexing planned with the contracts

    We design events for the subgraph from the start, so your app and analytics read clean data.

  5. Audit-ready at every milestone

    Each milestone ends with tests, docs and a tagged commit that an auditor can review.

Contracts
Solidity · Hardhat · Foundry · Truffle · Ganache · OpenZeppelin
Chains
Ethereum · Polygon · Arbitrum · Optimism · BNB Smart Chain · Tron
Data and storage
Subgraphs · IPFS · PostgreSQL
Apps and wallets
React · MetaMask · Trust Wallet

Risks we engineer for

Risks in Blockchain and DeFi work and how we handle them
RiskWhy it mattersHow we handle it
Re-entrancyAn external call can re-enter a function before balances update and drain funds.Checks-effects-interactions ordering, re-entrancy guards and tests that simulate hostile callers.
Oracle manipulationA flash loan can move a thin market's price and trigger bad liquidations.Time-weighted or aggregated feeds, staleness and deviation checks, and limits on sudden moves.
Upgrade and admin keysWhoever holds an upgrade key can change the rules or move funds.We recommend multisig ownership and timelocked upgrades, and we list every admin power.
Accounting and rounding errorsSmall math errors compound across interest, rewards and liquidations.Fixed-point math reviewed line by line, with fuzz and invariant tests on each formula.
Bridge compromiseBridges hold pooled funds and trust relayers or validators outside the chain.A clear relayer or validator design, rate limits and pause controls.

How delivery works

  1. Scope the mechanism

    We map the mechanism, the assets at risk and the chains you need.

    Output Written specification and milestone plan

  2. Architecture and threat model

    We design the contracts, roles and upgrade path, then list how each part could be attacked.

    Output Architecture document and threat model

  3. Milestone builds on testnet

    Each milestone ships to testnet with unit, fuzz and invariant tests.

    Output Tested contracts and a testnet deployment

  4. Audit, mainnet and after

    We freeze the code for an independent audit and fix the findings. Then we deploy, verify and stay on after launch.

    Output Audit report, verified contracts and a deployment record

Audit firms we have worked with

  • RD Auditors

Shipped work

Shipped to mainnet on

  • Ethereum
  • BNB Smart Chain
  • Polygon
  • Arbitrum One
  • zkSync Era
  • Avalanche
  • Mantle
  • Moonbeam
  • Moonriver
  • Kava
  • Shiden
  • Monad
  • Kasplex

Questions

Short answers to the questions we hear most often.

Can't find yours?

Ask us directlyBook a call
Which blockchains do you build on?

We have worked on 25+ blockchains, including Ethereum, Polygon, Arbitrum, Optimism, BNB Smart Chain and Tron. We choose the chain with you, based on users, liquidity and fees.

Do you audit the contracts you write?

We test and review every contract internally, then prepare it for an independent audit. Audit firms we have worked with include CertiK (opens in a new tab), Quantstamp (opens in a new tab), Halborn (opens in a new tab) and RD Auditors (opens in a new tab). We also audit contracts that other teams wrote.

Can you work on a protocol that is already live?

Yes. We start by reviewing the deployed contracts, then plan upgrades or new modules around what is already on-chain.

How do you handle admin keys and upgrades?

We agree the upgrade model with you before writing code. We recommend a multisig and a timelock for admin powers, and we document each one.

What does a DeFi build cost?

Every engagement is quoted after a scoping call. The mechanism, the number of contracts, the chains and the audit scope drive the quote.

What do we receive at the end?

Source code, tests, deployment scripts and verified contracts. You also get a record of every deployed address and admin role.

Can't find yours?

Ask us directlyBook a call

Have an agent, protocol or product to ship?

Send a short brief and we'll reply with times for a 30-minute scoping call.

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