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Senior engineering · Solidity / Smart contracts

Senior Solidity / Smart contracts engineering for production systems.

Production smart-contract engineering: Solidity, Foundry / Hardhat, audited deliverables, gas-optimized, upgrade-aware, and the operational discipline that distinguishes shipped contracts from GitHub demos.

In production
2020+
Senior bench
12+ G6/G9 engineers
Floor
G6+ on client work
Engagement
Outcome-led, not hourly

Why senior, not contractor

Solidity / Smart contracts in production is a different problem than Solidity / Smart contracts on a laptop.

Most smart-contract code shipped to mainnet today wouldn't survive a serious audit: unbounded loops, missing access controls, reentrancy without ReentrancyGuard, upgrade patterns no one can reason about. Prosigns ships smart contracts as production engineering: Foundry-led test discipline (fuzz, invariant, fork tests), gas optimization measured against benchmarks, upgrade patterns with explicit access controls, and audits scoped against the contracts that actually matter.

Senior floor

G6+ minimum

Bench depth

12+ G6/G9 engineers

In production

2020+

Engagement

Outcome-led SOW

Where Solidity / Smart contracts ships

6 sub-areas, grounded in shipped engagements.

Specific applications of Solidity / Smart contracts we’ve built and operate. Every example below maps to a real engagement, not a bullet on a stack-card.

  • 01

    Solidity contracts (EVM)

    ERC-20 / 721 / 1155 / 4626 / 6909, custom DeFi primitives, governance tooling, multi-sig integration. Audited deliverables.

  • 02

    Test discipline (Foundry)

    Fuzz tests, invariant tests, fork tests against mainnet state, gas snapshots in CI, coverage targets > 95% on the contracts that matter.

  • 03

    Upgrade patterns

    OpenZeppelin Transparent / UUPS / Beacon proxies, Diamond pattern (EIP-2535) where complexity warrants. Storage layout discipline.

  • 04

    Layer-2 + cross-chain

    Arbitrum, Optimism, Base, Polygon zkEVM. LayerZero / Wormhole / Axelar for cross-chain messaging. Bridge security review.

  • 05

    Move (Aptos / Sui)

    Move modules for Aptos and Sui with proper resource-typing, capability patterns, and the security guarantees Move was designed for.

  • 06

    Pre-audit hardening

    Slither, Mythril, Echidna, Halmos for symbolic execution. Pre-audit cleanup against the audit firm's checklist before billable hours start.

Stack depth

The Solidity / Smart contracts ecosystem, owned.

Frameworks, libraries, and runtime tools the bench has shipped in production. Not a CV-skim, a working depth.

Toolchain

  • Foundry
  • Hardhat
  • Forge
  • Anvil
  • Cast

Standards + libraries

  • OpenZeppelin
  • Solmate
  • Solady
  • ds-test
  • PRBMath

Static analysis + security

  • Slither
  • Mythril
  • Echidna
  • Halmos
  • Manticore

L2 + interop

  • Arbitrum
  • Optimism
  • Base
  • Polygon zkEVM
  • LayerZero

Frontend + indexing

  • wagmi
  • viem
  • Ethers.js v6
  • The Graph
  • Subsquid

Engagement models

Three ways to engage Solidity / Smart contracts engineers.

We don’t bill hourly contractors. Engagements run against outcomes, choose the shape that matches the work.

See engagement models
  1. Fixed-scope

    Defined deliverable, fixed price

    01

    When the deliverable is clear and the scope is bounded: an MVP, a migration, a discrete platform build. Senior engineering against a written outcome, not against a body count.

  2. Embedded squad

    Senior product team, ongoing

    02

    When the work is product-shaped and the cadence is continuous. A senior pod (engineering + design + PM as needed) embedded into your team, with the practice lead co-piloting from HELM.

  3. Managed services

    Steady-state operations

    03

    When the system is running and needs ongoing engineering ownership: operations, SLO defense, release management, security and compliance evidence. Monthly retainer against a published SLA.

Selected work

Solidity / Smart contracts engineering that shipped.

  • DeFi

    Lending-market smart contracts for a regulated DeFi protocol: Foundry-tested, Trail of Bits-audited.

    Zeropost-audit findings

    ERC-4626 vault contracts with custom liquidation logic, UUPS-upgradeable with role-based access. Foundry fuzz + invariant suite at 96% coverage. Cleared a Trail of Bits audit with no major or critical findings.

    Duration · 5 months

Brief us

Reply < 4 business hours

Have a Solidity / Smart contracts workload? Send a brief.

Five fields. Goes straight to the practice lead, not an SDR. We’ll reply with a senior engineer’s read on fit, scope, and the engagement model that suits the work.

Stack focus
Solidity / Smart contracts · selected

No SDRs · No drip · Senior engineer reply

FAQ

Questions buyers ask.

Everything below also appears in the proposal and the SOW: no surprises after signing.

  • Do you handle the audit process?

    We pre-harden against the audit firm's checklist before billable hours start, coordinate the audit engagement, and remediate findings with regression-tested fixes. We&rsquo;ve worked with Trail of Bits, OpenZeppelin, Spearbit, Code4rena, and Cantina across various engagements. We&rsquo;re not auditors ourselves and we don&rsquo;t pretend to be.

  • Foundry or Hardhat?

    Foundry as default: faster, better fuzz / invariant testing, native Solidity testing. Hardhat where the customer's existing toolchain or specific plugin ecosystem demands it. We ship both.

  • Is this staff-aug, or is it engineering-led delivery?

    Engineering-led delivery. We don't bill hourly contractors against your JIRA board. Every engagement runs against a defined outcome with a senior engineer accountable from kickoff to operating cutover. If you genuinely need staff-aug, discrete bodies, your management, hourly rates, we'll be honest and route you to a partner that fits.

  • What seniority floor are we talking about?

    G6 minimum (six-plus years in their craft) on every billable hour. Department leads are G9 or G10. We don't flex juniors onto the bench mid-sprint, we don't subcontract to delivery centers, and we don't dilute senior rates with mixed staffing. The bench in the proposal is the bench in production.

  • How does pricing work?

    Three engagement models published at /engagement-models/. Fixed-scope for defined deliverables, embedded squads for ongoing product work, managed services for steady-state operations. Rates depend on seniority, engagement length, and region. Discovery + scoping conversation is free; SOWs are written against deliverables, not bodies.

  • Where are your engineers based?

    Senior-only across Dallas, Doha, Lahore, and Islamabad. We staff against the engagement's needs (timezone, language, regulatory frame), not against arbitrary regional preferences. Most engagements run with a US/EU-aligned core and a follow-the-sun extended bench when the workload warrants it.

  • Will the engineers I see in the proposal be the engineers shipping the work?

    Yes. We name the engineers in the SOW, attach their profiles, and they're on the kickoff. We don't bait-and-switch with senior reviewers and junior execution. If a named engineer needs to roll off the engagement (rare), we surface a replacement from the same seniority tier with explicit handoff.

Talk to a Solidity / Smart contracts lead

Senior Solidity / Smart contracts engineering, accountable from kickoff.

Bring the workload: we’ll bring a senior engineer plus the practice lead most relevant to the work. 30 minutes, no obligation, no junior reps.