Smart contract development: write the rules down before the code

What a contract engagement should deliver

Quick test: Describe each contract function in one sentence a non-developer can follow. If you cannot, the rule is not clear yet.

Smart contract development translates a product’s agreed rules into code that can be tested and prepared for release on a selected blockchain. The useful outcome is not code in isolation: it is an implementation whose expected behavior, boundaries, and handoff are clear to the product team.

This service is a fit when your project needs custom on-chain logic, such as a token-related contract, vesting schedules, staking flows, or contract functions that a dApp will call. If the contract is one part of a wider product, we can align the plan with Web3 development and dApp development, so the interface and contract agree on inputs, permissions, and user actions.

Before implementation, prepare:

• A plain-language description of each user action and its expected result.
• The blockchain you intend to use and any existing contract or product dependencies.
• Rules for access, timing, changes, and exceptional cases.
• A named decision-maker who can resolve open product questions.

If you cannot yet specify a rule, mark it as undecided rather than letting it become an implicit engineering choice. We turn open questions into a review list, then confirm the contract plan with you before development begins.

How do requirements become tested behavior?

We map each requirement to observable contract behavior and a test before treating it as ready for release. That gives the project team a practical way to check whether the implementation matches the intended rules, rather than relying on a broad description such as “support staking.”

The working sequence is straightforward: clarify user roles and permitted actions, define expected state changes, identify invalid or incomplete inputs, then implement and test the agreed cases. For each function, the acceptance criteria should answer what a valid call does, who may make it, and what should happen when a condition is not met. We review those criteria with your product owner before they become the basis for development.

A useful plan distinction is between contract behavior and product experience. The contract handles the rules assigned to it; a connected app may still need to explain states, display data, or guide users through a transaction. Where both are in plan, we coordinate that boundary with dApp development. For a token that needs creation and deployment as well as custom logic, align the contract requirements with token creation and deployment.

You receive a reviewable record of the agreed behaviors and their corresponding tests. That makes later product changes easier to assess: the team can identify which existing rules are affected before approving an update.

Your 7-point contract specification checklist

Write these 7 items down before any code is written. They become the acceptance criteria that every test is checked against. Keep the ticked list with your records, because it is the quickest way to explain later what was agreed.

1. List each contract and its one job.
2. Write who may call each function.
3. Define vesting and staking schedules with exact numbers.
4. Decide whether the contract can be upgraded, and by whom.
5. List the failure cases and the expected result for each.
6. Choose the chain and the token standard.
7. Plan an independent review before release.

Terms in one line

Vesting: releasing tokens to holders gradually on a fixed schedule.

Upgradeable contract (in plain words: a contract whose logic can be replaced after deployment).

Specifying vesting and staking rules

Vesting and staking contracts need explicit rules for eligibility, timing, user actions, and the outcomes the product displays. Naming the feature is not enough; the contract plan should describe the cases the implementation must support and the cases it must reject.

For vesting, decide who receives an allocation, what event starts the schedule, how releases are calculated, and whether any changes are permitted after the schedule is set. Confirm how the product should handle a user checking an allocation or requesting an available release. For staking, define the actions a participant can take, which conditions apply to entry and exit, and how the contract represents relevant balances or states. These are requirements to confirm with your team, not default settings we silently choose.

Use this preparation checklist:

• Identify the roles that can create, administer, or use each contract function.
• Write down timing rules and what counts as a valid action.
• Decide how exceptional cases should be handled and communicated.
• Separate confirmed product rules from policy or token decisions still under review.

Where token supply or distribution is part of the same release, coordinate the plan with token creation and deployment. If users will interact through a dedicated wallet experience, discuss the connection with crypto wallet development early, so the contract and interface requirements are reviewed together.

What the engagement includes

Rule of thumb: Tests show what you thought of. An independent review shows what you did not.

The engagement covers the agreed contract plan and the materials your team needs to review, test, and prepare that work for release. We confirm what you receive at kickoff so there is a shared definition of completion, including any work that depends on your team or an external auditor.

Depending on the approved plan, what you receive can include:

• A written summary of contract requirements and acceptance criteria.
• Custom contract implementation for the selected blockchain and agreed functions.
• Tests covering the behaviors and edge cases defined during planning.
• Build and release notes that explain what is ready for review and what remains open.
• Coordination of an independent audit, including packaging the agreed materials and organizing responses to findings.

Audit coordination means helping the team prepare a clear review handoff and track feedback into code changes. It is distinct from representing that an audit has occurred or that an auditor has approved the code. If your product needs a website or landing page to explain contract behavior, the technical plan can be coordinated with Web3 website and landing development.

A strong handoff lets your internal team understand what was built, what was tested, and which decisions remain theirs. We review the what you receive with your project owner, record accepted changes, and make the release status clear before work is treated as complete.

How the project is planned and reviewed

The project moves from requirements to implementation through named review points, with timing set from the confirmed plan. A small, well-defined contract and a multi-feature system do not need the same plan, so we first establish what is being built and who will make decisions.

At kickoff, we check the selected blockchain, contract dependencies, product rules, existing code, and the people responsible for approvals. During development, we share progress against the agreed requirements and raise questions that could change behavior before they become last-minute surprises. You review implementation against the acceptance criteria, and we capture requested changes as specific items for confirmation.

The schedule also accounts for external review where requested. We coordinate when the materials are ready, keep auditor feedback connected to the relevant requirement, and confirm which changes are included in the agreed plan. Your team should plan to provide prompt answers to product and access questions; unresolved decisions can hold up implementation or release preparation.

To keep the work easy to assess, ask for a progress update that separates completed items, open decisions, test status, and next actions. MarketingExtra uses a direct engineer-to-client review of acceptance criteria and test coverage, so the people approving product behavior can see what each test is intended to establish. The resulting delivery plan is confirmed with you before the build proceeds.

What to know before you release code

A careful development process improves reviewability, but testing and audit coordination do not remove every release risk. Tests can only check the cases they cover, and an independent auditor may identify issues or request changes; deployment should wait until your team approves the exact release and target network.

For a responsible handoff, confirm that the deployed version matches the version your team reviewed, that release permissions are understood, and that the project has an owner for post-release questions. Keep a record of the accepted requirements, test results, auditor feedback where applicable, and the final release decision. These materials help your team distinguish verified work from decisions or operating responsibilities that remain outside the development plan.

If contract development is part of a larger build, align the release plan with the wider Web3 development plan rather than treating the contract as a separate finish line. Share your target blockchain, a brief description of the contract’s purpose, and any existing specifications or code with MarketingExtra. We will review the materials, identify unanswered product decisions, and return a written plan for the work.

Send 3 things: your product rules, your target chain, and your timeline for the review.

How it works

1. Share the product rulesSend the intended contract behavior, target blockchain, existing code or specifications, and any known dependencies. Mark unresolved decisions clearly.
2. Confirm plan and acceptance criteriaWe review roles, actions, exceptional cases, and what you receive with your decision-maker. The agreed criteria establish what development and testing will cover.
3. Build and test the agreed behaviorThe engineer implements the planned contract and checks it against the accepted test cases. Questions that affect behavior are brought back for your decision.
4. Coordinate independent reviewIf audit coordination is included, we prepare the agreed materials, organize feedback, and track requested changes with your team.
5. Review the release handoffYou review the final what you receive, test record, and open items before approving the release plan for the selected network.