// US-based Solidity developers
Free project plan & cost estimate in 48 hours.
Senior Solidity developers, based in the US, working your hours
Smart contracts and blockchain back-ends, built by US engineers who treat testing and security reviews as non-negotiable.
- Interview engineers before you pay anything
- 100% U.S.-based, working your hours
- No brief or spec needed to get started
First 5 Dev Hours Free
Project plan. Roadmap. Cost & ROI estimation.
Real engineers. Real conversations.
Talk to an engineer. Not a salesperson.
Free · No commitment · Project-focused call
Most teams interview matched engineers within a week
Not the right fit? We bring in a replacement
Get your free project plan
Three quick steps. No brief needed.
Free · No commitment · Reply within one business day
// teams we've worked with
“NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag.”
Sound familiar?
- You need contracts shipped without cutting corners on security.
- Offshore blockchain teams have been hard to vet and hard to reach.
- Hiring a senior Solidity developer full-time is taking months.
- You need someone senior enough to make decisions, not just close tickets.
What our Solidity engineers build
Smart contracts
Solidity contracts with full test coverage, built for audit.
Security review prep
Code hardened and documented before it goes to an outside auditor.
App integration
Wallets, indexers, and back-ends connected to your contracts.
How it works
- 01
Pick a time
Book a 30-minute project call directly in our calendar.
- 02
Talk through the problem
Tell us what needs building, what's stuck and what success looks like. No spec needed.
- 03
Your plan in 48 hours
Get your project plan, roadmap, cost and ROI estimates. The plan is yours to keep.
- 04
First 5 dev hours free
Agree the scope with our team. Decide whether to continue before any paid work begins.
Common questions
Will this turn into a sales pitch?
No. The call is about your project: what needs building, what's stuck, and whether we have the right engineers. If we're not a fit, we'll say so.
What do I get for free?
A project plan, roadmap, cost estimate and ROI estimate within 48 hours of your project call. Your first 5 development hours are free, too. We agree the scope and any paid work with you before proceeding.
Do I need a spec or brief?
No. Tell us the problem in plain words and we'll help shape the scope with you.
Are the engineers really in the U.S.?
Yes. Every engineer lives and works in the United States. No offshore hand-offs, and that's in the contract.
What our clients say
"NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag."
"Their R&D tax credit workflow platform paid for itself in the first filing season."
"AI-native from day one. Our IRS transcript pipeline runs 24/7 without a human in the loop."
"Property tax appeals used to take weeks. Their comp analysis tooling turned it into hours."
"The AI intake agent handles our tier-1 patient calls with a hand-off cleaner than our old call center."
"POS, inventory, ordering — all unified. We finally have one source of truth across every location."
"The procurement platform paid for itself in the first quarter of use."
"They shipped our matching engine in 6 weeks. Our old team would've taken 6 months."
"Enterprise-grade delivery without the enterprise-agency price tag."
"Their team plugged into our sprint on day one. Zero ramp time."
"NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag."
"Their R&D tax credit workflow platform paid for itself in the first filing season."
"AI-native from day one. Our IRS transcript pipeline runs 24/7 without a human in the loop."
"Property tax appeals used to take weeks. Their comp analysis tooling turned it into hours."
"The AI intake agent handles our tier-1 patient calls with a hand-off cleaner than our old call center."
"POS, inventory, ordering — all unified. We finally have one source of truth across every location."
"The procurement platform paid for itself in the first quarter of use."
"They shipped our matching engine in 6 weeks. Our old team would've taken 6 months."
"Enterprise-grade delivery without the enterprise-agency price tag."
"Their team plugged into our sprint on day one. Zero ramp time."
Hire a US-based Solidity developer to build, extend, or maintain smart contracts and the dApp integrations that depend on them. Common projects include ERC-721 collections, ERC-1155 assets, access-controlled registries, and escrow workflows. A useful project brief identifies the compiler version, deployed addresses, permission model, and expected transaction flows so contract changes do not quietly break existing wallets, frontends, or indexed events.
A Solidity 0.8.x workflow can combine Foundry or Hardhat with OpenZeppelin libraries, Slither checks, and viem-based frontend integration. Pin dependencies, test custom errors and emitted events, and rehearse deployments before changing production contracts. NextGen Coding Company engineers are senior, and many have 10+ years of experience. They work your hours and attend your standups. Book a 15-minute call to outline your repository and immediate engineering needs.
Frequently asked questions
- Should our Solidity project use Foundry or Hardhat?
- Foundry fits teams that want Solidity-native tests, fuzzing, invariant testing, and command-line deployment tools. Hardhat suits JavaScript or TypeScript-heavy workflows and projects already built around its plugins. Evaluate the existing repository and CI setup rather than switching automatically. Some projects use both, but duplicated configuration and inconsistent compiler settings need careful control.
- Can a Solidity developer update our existing ERC-721 contract?
- That depends on how the deployed contract was designed. An immutable ERC-721 contract cannot have its code replaced; changes may require a new deployment or an existing extension mechanism. A proxy-based contract can support upgrades, subject to permissions and storage compatibility. Review ownership, metadata controls, integrations, and migration consequences before selecting an approach.
- What is involved in upgrading to Solidity 0.8.x?
- Moving from an older compiler requires more than changing the pragma. Solidity 0.8.x adds checked arithmetic by default and includes breaking changes that can affect existing assumptions. Review dependency compatibility, explicit conversions, revert behavior, and generated bytecode. Re-run tests and static analysis, and check deployment constraints; deployed immutable contracts still require a separate migration strategy.
- How do Solidity contracts connect to a React frontend?
- A React application typically uses an ABI and deployed contract address through libraries such as viem and wagmi. Integration work includes wallet connection, chain selection, transaction simulation, signature requests, and receipt handling. Test rejected requests, custom errors, stale reads, and network changes. Event indexing may be necessary when the UI needs historical activity rather than current contract state.
- What happens if the Solidity engineer is not the right fit?
- If the match is not right, NextGen Coding Company brings in a replacement with a proper hand-over. For a Solidity repository, the hand-over should capture compiler settings, deployment scripts, contract addresses, test commands, and unresolved risks. Keep signing authority in your controlled process rather than making production access depend on one engineer's personal wallet.
- Are your developers really based in the US?
- Yes. Every engineer lives and works in the United States. No offshore subcontracting and no hand-offs to another team. That's written into the contract.
- How fast can someone start?
- Most teams interview matched engineers within a week of the first call. Start dates depend on your interview process.
Related reading
- How to hire a software developer
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- Hiring test for senior engineers
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- Senior engineer salary guide 2026
What the market pays.
- Onshore vs offshore vs nearshore
The honest tradeoffs.
- Forward deployed engineers
Need an owner, not just capacity?
- Resource library
Every guide and benchmark we publish.
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