Smart contract architecture, audited wallet UIs, and on-chain payment flows — engineered so thoroughly that your users never have to think about the blockchain underneath.
Tools & Technologies
Self-sovereign credential vault built on zk-SNARKs and IPFS — locally encrypts sensitive data with AES-256, anchors a proof of ownership to the blockchain without exposing the underlying data, and uses Lit Protocol for programmable access control. The user holds the master keys; the protocol holds nothing.
Decentralised freelance escrow on Polygon — milestone-based smart contracts hold and release funds automatically on client approval, with Chainlink oracle verification for dispute resolution. Zero platform fees, sub-second settlement, and a non-custodial wallet onboarding flow designed for freelancers who have never used a crypto wallet before.
Consumer e-commerce app with blockchain payments running invisibly under the hood — standard shopping UI with instant on-chain settlement, zero chargebacks, and verified seller provenance. Built to demonstrate that Web3 payments can be completely transparent to a mainstream shopper who just wants to check out in three taps.
We write smart contracts with security patterns built in from the first line — reentrancy guards, access control, integer overflow protection, and upgradeability design where appropriate. When you go to audit, the auditor is reviewing solid architecture, not finding architecture problems for the first time.
Gas fee estimation, transaction state management, failed transaction recovery, and non-custodial onboarding flows — we treat every on-chain interaction as a UX problem with real drop-off consequences, not a technical formality. Users who've never held ETH can complete a transaction without confusion.
We build on EVM-compatible chains (Ethereum, Polygon, Base, Arbitrum) and structure contracts so migration or multi-chain expansion doesn't require a full rewrite. The chain you launch on today doesn't have to be the chain you scale on tomorrow.
We follow established security patterns — checks-effects-interactions, role-based access control, event logging for every state change — and run Hardhat test suites against known vulnerability vectors before a line of code goes to an external auditor. First-pass audit clearance isn't luck; it's the result of writing contracts the right way from the start.
Every gas fee moment, transaction confirmation, and wallet connection step is a potential drop-off. We design and test these moments specifically — clear status states, accurate fee estimates, graceful failure handling — so the on-chain parts of your product feel as smooth as the off-chain parts.
On-chain bugs can't be patched with a hotfix. We build upgrade paths, pause mechanisms, and owner controls into contracts where the use case warrants it — so a post-launch issue is a managed fix, not an irrecoverable exploit.
Contract inefficiency is a direct tax on every user transaction. We optimise storage layout, batch operations where possible, and benchmark gas costs against comparable production contracts before deployment — so your users aren't paying more than they need to for every interaction.
App Stop takes ownership of both product thinking and execution. We combine design clarity, engineering discipline, and market context to ship experiences that are fast, usable, and ready to scale.
Delivery Model
We define the product problem, success metrics, and the delivery track that fits the business.
We shape the technical foundation, delivery milestones, and risk controls before sprint work begins.
We execute in focused iterations with demos, QA, instrumentation, and release planning in parallel.
We launch with observability, support, and a practical roadmap for what comes next.
Selected Work
FAQ
We build the full stack — Solidity contracts, wallet integration, dApp interface, subgraph indexing via The Graph, and the admin dashboard needed to manage it after launch. You get a complete, deployable Web3 product with everything needed to run it, not just the contract layer handed off with documentation.
Yes. We start with a contract audit and architecture review so we understand exactly what exists and what it does before writing a single line of new code. We can extend an existing contract suite, improve the dApp interface on top of it, or redesign the user experience without touching the underlying protocol. If the existing contracts have known vulnerabilities, we'll flag them before taking on any work that depends on them.
By treating every on-chain interaction as a UX design problem, not an engineering formality. Gas fee moments, transaction confirmations, wallet connection flows, and failed transaction states are all points where users abandon Web3 products — we design and user-test each one specifically. The goal is a product where a user who doesn't know what a private key is can complete every flow without friction or confusion.
We don't perform external audits ourselves — that's a conflict of interest, and any agency that audits its own contracts isn't giving you an independent review. What we do is write contracts that are audit-ready: established security patterns, comprehensive Hardhat test coverage, and no known vulnerability classes before the code leaves our hands. We can recommend reputable third-party auditors (Trail of Bits, Certik, OpenZeppelin) and coordinate the audit engagement as part of the project.
For contracts that handle user funds or sensitive state, we build in upgrade mechanisms (proxy patterns or modular architecture) and pause functionality where the use case allows — so a critical issue can be responded to without losing user funds or requiring a full redeployment. For contracts where immutability is a feature (as it often is in DeFi), we're explicit about that tradeoff during architecture design, and we invest more heavily in pre-deployment testing and formal verification to compensate. We don't promise zero bugs; we promise a contract architecture that makes bugs manageable.
