// US-based Solidity developers · Blockchain
Free project plan & cost estimate in 48 hours.
Senior Solidity developers for blockchain and Web3 teams, based in the US
Engineers who treat security and testing as non-negotiable and build protocols and back-ends ready for outside audit.
- 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?
- Security mistakes are permanent and expensive.
- Vetting offshore Web3 talent is hard.
- Audits keep finding issues late.
- You need senior people who can own protocol decisions.
What our Solidity engineers build for blockchain and Web3 teams
Protocols & infrastructure
Contracts, indexers, and node tooling built and documented for audit.
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.
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 for blockchain infrastructure such as EVM protocol contracts, staking systems, cross-chain message receivers, and on-chain governance. For Solidity 0.8.x projects, the scope should cover contract behavior and operational assumptions: who can upgrade the implementation, which messages are trusted, and what happens when a sequencer or relayer stops. Those decisions shape the architecture before deployment scripts are written.
Foundry, OpenZeppelin Contracts 5.x, and fork testing provide a practical foundation for implementation and verification, but chain-specific behavior still needs explicit testing. Review finality assumptions, replay protection, storage layouts, and event indexing across every target network. NextGen Coding Company provides senior engineers who live and work in the US. We sign an NDA and full IP assignment before touching code; book a 15-minute call to discuss your protocol.
Frequently asked questions
- Can one Solidity codebase support Ethereum and EVM L2 networks?
- Often, but EVM compatibility does not mean identical operating conditions. Review supported opcodes, gas behavior, block timestamps, sequencer dependencies, and finality assumptions for each network. Use Foundry fork tests against the intended deployments and maintain explicit chain configurations. Cross-chain deployments also need separate address management, verification steps, and monitoring for privileged actions.
- How should Solidity contracts validate cross-chain messages?
- Validate the messaging endpoint, source chain, sender, and message identifier before executing an action. Define replay protection and how the receiver handles delayed, duplicated, or out-of-order messages. The bridge or messaging protocol adds its own trust assumptions, so testing should include paused delivery, failed execution, retries, and compromised permissions rather than only successful transfers.
- How do you test staking and governance contracts with Foundry?
- Use unit tests for individual rules, fuzz tests for varied inputs, and invariant tests for properties such as conserved accounting and restricted withdrawals. Advance time and blocks to exercise reward accrual, voting delays, and proposal execution. Fork tests help check external integrations, while adversarial test actors expose reentrancy paths and unexpected token behavior.
- Should a blockchain protocol use UUPS or transparent proxies?
- Choose based on upgrade authority, operational tooling, and how implementation contracts will be maintained. UUPS places upgrade logic in the implementation; transparent proxies separate administration through proxy behavior and associated tooling. Both require initializer protection, storage compatibility checks, and controlled upgrade permissions. Document the upgrade process and test it against existing state before deployment.
- What should we prepare before interviewing a Solidity protocol developer?
- Share the target chains, architecture diagram, contract repository, test suite, and known trust assumptions. Explain whether the work involves a new protocol, an upgrade, or remediation of audit findings. NextGen Coding Company signs an NDA and full IP assignment before touching code. Most teams interview matched engineers within a week of the first call.
- 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
What to check before you sign.
- Hiring test for senior engineers
How to vet senior talent fast.
- 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.







