delta for Smart Contract Developers

Unlike smart contracts, which couple business logic and security constraints into a single onchain program, delta’s guardrail model decouples execution from verification (and verifiability).

This architecture removes the "blockchain constraints" from your business logic, allowing delta applications to be built, scaled, and maintained exactly like standard web2 backend services.

We summarize the benefits of the delta model in this table:

Metric	Smart Contracts	Guardrail Model	Estimated Impact
Execution Model	Public smart contracts	Arbitrary private business logic, public local laws (settlement constraints)	Use any programming language, keep proprietary code private while retaining verifiability and security
Audit Scope	Entire execution path (100% of code)	Local laws only (<5% of code)	90-99% cost reduction
Upgrades	Extremely painful, requires audits	Same as web2, without harming security	10-100x faster ship cycles
Computational Cap	Limited by block gas limit	Limited by server hardware	Unbounded complexity
Talent Pool	Smart contract engineers (~20k active)	Any backend developer (~25M active)	1000x talent access

Conceptual Overview

In traditional blockchain development (e.g. EVM), developers write imperative code: a set of sequential instructions that the blockchain must execute to transition state. The security of the application relies on the correctness of every instruction in this execution path.

The guardrail model shifts the focus from Proof of Execution to Proof of Validity.

In this model, the application is split into two distinct components:

1. The Server (Execution Layer): A program that generates state transitions. It can be written in any language, using any software stack and even hardware.
2. The Guardrail (Constraint Layer): A verifiable set of rules (constraints) that accepts or rejects state transitions based on validity, independent of how the result was calculated.

The following table illustrates the difference:

Feature	Smart Contracts	Guardrail Model
Business Logic	Imperative: Defines how to change state.	Declarative: Defines what state is valid.
Execution	Onchain (replicated or proven).	Offchain (executed by the server).
Verification	Implicit (outcome of execution).	Explicit (cryptographic proof of constraints).
Compute Constraints	Limited by block gas limit.	Limited only by chosen hardware.
Data Visibility	Inputs (transactions) and logic are public by default.	Inputs/logic can remain private; only the results and constraints are public
Audit Surface	Full execution codebase.	Constraint logic only.

Developer Workflow

Developing in the guardrail model follows a different lifecycle than standard smart contract development:

1. Define Constraints: Identify the safety properties of the system (e.g., "The sum of inputs must equal the sum of outputs"). This logic is implemented as a ocal law.
2. Implement Execution: Build the application logic (server) as a delta domain which uses standard software stacks (Rust, Python, TS, etc.) to generate valid state transitions that satisfy the constraints.
3. Prove & Verify: The domain generates a proof for a given transition. User transactions settle on delta when the corresponding proof to the state change verifies on the base layer.

In-depth Consequences

In the guardrail model, your application is simply a web2 server with additional cryptographic constraints. This has a huge impact on the developer experience:

I. Development Overhead (Build)

In the guardrail model, "gas optimization" is replaced by standard server optimization.

#	Factor	Description of Friction	delta Equivalent
1	Gas Optimization	Developers spend weeks rewriting perfectly working logic (e.g., bit-packing booleans into uint256, avoiding loops) to save users $2 in fees.	Code is written for readability. Hardware is cheap; nobody optimizes for CPU cycles anymore.
2	Fixed-Point Math	Solidity doesn't support floating point numbers. You must manually manage decimals (Wad/Ray math), leading to complex precision loss handling and overflow checks.	float amount = price * quantity
3	Oracle Integration	You cannot verify real-world data. You must integrate Chainlink feeds, handle "stale price" checks, fallback logic, and fund subscription accounts for updates.	response = requests.get(api_url)
4	Data Structures	You cannot use HashMaps, complex arrays, or large strings efficiently. You are forced to architect "weird" storage patterns (e.g., Linked Lists via mapping) to fit EVM constraints.	List<User>, JSON, Dict. Standard libraries handle everything.
5	MEV & Reentrancy	You must defensively code against transaction ordering attacks (sandwich attacks) and reentrancy. Logic is often convoluted just to prevent these specific exploits.	Standard thread safety or database ACID transactions.
6	Indexing Layer	You cannot efficiently query your own data (e.g., "Show all NFTs owned by User X") from the smart contract. You must build a separate "Subgraph" or middleware just to read your own database.	SELECT * FROM items WHERE owner = 'X'

II. Maintenance Overhead (Maintain)

In the guardrail model, "immutable contracts" are replaced by mutable engines protected by immutable Laws.

#	Factor	Description of Friction	delta Equivalent
7	Immutability (Proxies)	You can't just update code. You must use "proxy patterns" (delegatecall). You must manually ensure storage slots don't collide between Version 1 and Version 2, or you corrupt the entire database.	git push. The server restarts with new code. Guardrails/local laws are unaffected
8	State Migration	If you change a data structure, you cannot run a SQL migration script. You often have to require users to manually migrate their funds from contract V1 to contract V2.	ALTER TABLE users ADD COLUMN... (Automated in <1 min).
9	Fork-Based Testing	You cannot reliably mock dependencies (like Uniswap or Aave). You must set up a "mainnet fork" environment to test your code against the actual state of the blockchain at block #15,000,000.	Standard unit/integration tests with mocked interfaces.
10	Incident Response	If a bug is found, you cannot simply "patch" it. You must trigger a "pause" (if implemented), convene a multisig council (requires 4/7 humans to wake up), and sign a transaction to freeze the protocol.	rollback to previous commit. Done in 5 minutes.
11	Governance Ops	Implementing config changes (e.g., changing a fee) requires writing a "proposal contract," verifying it, and queuing it in a timelock for 48 hours.	Changing a variable in a config file or admin dashboard.

III. Security and Talent Overhead

In the guardrail model, you audit the rules of the game, not the players' strategy.

#	Factor	Description of Friction	delta Equivalent
12	Third-Party Audits	You cannot ship "MVP" code. You must pay external firms to read every line. This creates a "waterfall" development cycle where you code for 3 months, wait 2 months for audit, fix, and re-audit.	Continuous integration/continuous deployment (CI/CD).
13	Formal Verification	For high-value apps, audits aren't enough. You write mathematical specs (in languages like Certora or K) to prove your code is bug-free. This is effectively writing the code twice.	Writing standard unit tests (Jest/PyTest).
14	Talent Scarcity	Hiring a developer who understands both "software engineering" AND "EVM security" is incredibly hard. You pay a premium and spend months sourcing.	Hiring a Java/Python developer is a commoditized, efficient market.