Do you replace an external audit?

No, and you should not want us to. We harden the codebase so the external audit is faster, cheaper and less alarming. We coordinate the audit and fix the findings.

Which chains do you work on?

EVM chains primarily — Base, Optimism, Arbitrum, Polygon and Ethereum mainnet. We have shipped Rust for non-EVM environments when the product justified it.

Can you do this without the crypto branding?

Yes, and increasingly we do. Stablecoin settlement and tokenised assets inside an otherwise conventional product is now a large share of this practice.

Services

Blockchain & Web3 Engineering

Contracts that hold value and survive an audit.

Blockchain is the practice we started with, and the one with the least forgiving definition of done. Once a contract is deployed, a bug is not a ticket — it is a loss.

So we work audit-first: invariants written alongside the contracts, static analysis and fuzzing in CI, and an internal review by a second senior engineer before anything reaches an external auditor. By the time Spearbit or Cantina see the codebase, the interesting findings are already fixed.

Around the contracts we build the parts users actually touch: account-abstraction wallets, gas sponsorship, indexers, dashboards and the fiat on-ramps that make the whole thing usable by people who do not care that it is on-chain.

Discuss this practice All services

Capabilities

What this practice actually covers.

Smart contract engineering

Solidity written for auditability first. Small surface area, explicit invariants, and no cleverness that a reviewer cannot follow.

Solidity with Foundry, invariant and differential testing
Upgradeability patterns with timelocks and clear governance
Gas profiling and optimisation where it changes user cost
Formal specification of critical invariants

Wallets & account abstraction

The wallet is the product for most users. Passkeys, sponsored gas and recovery flows that do not require a seed-phrase lecture.

ERC-4337 smart accounts, passkeys and session keys
Paymaster-sponsored gas and stablecoin-denominated fees
Social and guardian recovery flows
Fiat on-ramp and off-ramp integration with KYC providers

Protocol & token infrastructure

The mechanics around the contracts: supply schedules, vesting, liquidity and the treasury operations that keep a token programme defensible.

Tokenomics modelling with supply and cashflow simulation
Vesting, distribution and liquidity bootstrapping
Safe multisig, Zodiac modules and treasury controls
On-chain reporting and transparency dashboards

Indexing, data & dApp frontends

On-chain data is useless until it is queryable. We build the indexing layer and the interfaces that sit on it.

Subgraphs, custom indexers and Postgres mirrors
Real-time event pipelines with reorg handling
React dApps with viem and wagmi, wallet-agnostic
Analytics dashboards for protocol and treasury metrics

Security & audit readiness

We do not replace an external audit — we make it cheap. A hardened codebase turns a three-week audit into a two-week one with fewer findings.

Slither, Echidna and Foundry invariants in CI
Threat modelling and internal review by a second senior engineer
Audit coordination with Spearbit, Trail of Bits and Cantina
Monitoring, circuit breakers and incident-response runbook

Real-world asset & payment rails

Increasingly the interesting work is where chain meets balance sheet — stablecoin settlement, tokenised assets and compliant transfer logic.

Stablecoin payment and settlement flows
Tokenised asset structures with transfer restrictions
Compliance hooks — allowlists, attestation, travel rule
Reconciliation between on-chain events and your ledger

Deliverables

What lands in your account.

Audited, verified contracts deployed to your target chains
Foundry test suite with invariants and fuzz campaigns
Deployment scripts, upgrade plan and key-management policy
Indexer, dashboards and on-chain monitoring with alerting
Incident-response runbook and post-launch support window

Stack

Solidity
Foundry
viem
wagmi
ERC-4337
Base
Optimism
Arbitrum
The Graph
Safe
Rust

Chosen per engagement, not by habit. If your team already runs something else and it works, we work in it rather than around it.

Staffed by

Every engagement in this practice is delivered by a named team you interview yourself — designed, hired and led through our team-building practice.

See the people

Engagement

Three ways to start.

Indicative starting figures for a typical engagement, excluding VAT. Your actual number comes from a written scope — but it will be in the same neighbourhood.

Protocol Design Sprint

Specification, threat model and a costed build plan.

Duration: 2 weeks
Team: Contract lead + architect
From: €14,000

Mainnet MVP

Contracts, frontend and indexing, audit-ready.

Duration: 8–12 weeks
Team: 3–5 specialists
From: €89,000

Protocol Retainer

Upgrades, monitoring and ongoing protocol work.

Duration: Rolling
Team: 1–3 specialists
From: €16,000 / month

FAQ

Questions about this practice.

Ask us directly

Do you replace an external audit?: No, and you should not want us to. We harden the codebase so the external audit is faster, cheaper and less alarming. We coordinate the audit and fix the findings.
Which chains do you work on?: EVM chains primarily — Base, Optimism, Arbitrum, Polygon and Ethereum mainnet. We have shipped Rust for non-EVM environments when the product justified it.
Can you do this without the crypto branding?: Yes, and increasingly we do. Stablecoin settlement and tokenised assets inside an otherwise conventional product is now a large share of this practice.

Often combined with

Get started

Tell us what you need built — or who you need building it.

Send us the situation as it actually is. You get back a shaped engagement, a named team, a fixed timeline and a number you can put in front of a board.

Start a conversation

besarta@blocify.io +49 1575 5863757

A partner replies within one business day — with questions, not a sales sequence.