We architect and deploy custom smart contracts that form the backbone of your application. Our engineers write in Solidity 0.8+ and Rust, leveraging battle-tested libraries like OpenZeppelin and following formal verification patterns to eliminate vulnerabilities before deployment.
LABS
Services
StarkNet & zkSync Subscription Contract Development
Privacy-preserving, highly scalable recurring billing logic built on Cairo for StarkNet and Solidity for zkSync Era. Leverage ZK-rollup technology for cost-effective, enterprise-scale subscriptions.
Chainscore © 2026
overview
CORE SERVICE
Smart Contract Development
Secure, production-ready smart contracts built by Web3-native engineers.
- Full Lifecycle Development: From initial design and
Hardhat/Foundrytesting to mainnet deployment and verification. - Security-First Approach: Every contract undergoes internal audits and is built for upgradeability via transparent proxy patterns (
ERC-1967). - Gas Optimization: We minimize on-chain costs, targeting 20-40% gas reduction versus unaudited code.
Deliver a secure, auditable foundation for your token, DeFi protocol, or NFT project in as little as 3 weeks.
key-features-cards
ENGINEERING EXCELLENCE
Core Technical Capabilities
We deliver production-ready, secure subscription infrastructure for StarkNet and zkSync, built on verifiable engineering principles and battle-tested patterns.
01
Zero-Knowledge Smart Contract Development
Architect and deploy Cairo and Zinc smart contracts for StarkNet and zkSync Era. We implement complex business logic with gas-efficient zk-proofs, ensuring your subscription models are both private and scalable.
Cairo 1.0+
Language
OpenZeppelin
Standards
02
Secure Payment Abstraction & On-Ramps
Integrate ERC-4337 Account Abstraction for gasless user onboarding and flexible payment options. We build custom paymasters to support subscriptions in stablecoins, native tokens, or sponsored by the application.
ERC-4337
Standard
Multi-Currency
Support
03
Automated Billing & Revenue Management
Implement robust, fault-tolerant cron jobs and keeper networks to handle recurring charges. Our systems ensure reliable revenue collection with automatic retry logic and failed payment handling.
99.9%
Execution SLA
Real-time
Analytics
04
Cross-Chain Subscription Portability
Design subscription NFTs or state proofs that enable users to maintain access across L2s and even to Ethereum L1. Future-proof your service with interoperability at the core.
StarkNet <-> zkSync
Bridge Ready
ERC-6551
Token Standard
05
Comprehensive Security & Auditing
From initial design review to final deployment, security is paramount. We employ formal verification for critical functions and facilitate audits with leading firms like Trail of Bits and Quantstamp.
Formal Verification
Method
Third-Party Audits
Included
06
Scalable Off-Chain Infrastructure
Build the supporting backend: secure API gateways, encrypted user data management, and real-time notification systems (email/SMS/Webhook) that scale with your subscriber base.
< 100ms
API Latency
SOC 2
Compliance
benefits
DELIVERABLES & GUARANTEES
Business Outcomes for Your Product
Our StarkNet & zkSync subscription contract development delivers measurable results that accelerate your go-to-market and ensure long-term operational integrity.
01
Production-Ready Smart Contracts
Deploy fully audited, gas-optimized Cairo/Solidity smart contracts for recurring billing, membership tiers, and prorated upgrades. Built with OpenZeppelin standards and custom logic for your specific business model.
2-4 weeks
From spec to mainnet
Zero
Critical audit findings
02
Seamless On-Chain & Off-Chain Integration
End-to-end payment stack with automated reconciliation. We integrate your subscription logic with secure payment gateways, backend APIs, and real-time analytics dashboards for complete financial visibility.
< 1 sec
Payment confirmation
100%
Transaction integrity
04
Optimized User Experience & Gas Costs
Engineer frictionless subscription flows with meta-transactions for gasless sign-ups and batched operations. Our optimizations reduce user transaction costs by up to 70% compared to naive implementations.
~70%
Gas cost reduction
1-click
User sign-up flow
05
Scalable Architecture & Future-Proofing
Design modular systems that scale with your user base. We build with upgradeability in mind, allowing for new feature rollouts, pricing model changes, and support for emerging L2 standards without service disruption.
10k+ TPS
Theoretical scalability
Zero-downtime
Upgrades
06
Dedicated Technical Partnership
Beyond delivery, you get direct access to our engineering team for post-launch support, monitoring setup, and strategic advice on leveraging new L2 features for your subscription model's growth.
24/7
Protocol monitoring
30-day
Included support
Technical & Strategic Comparison
StarkNet vs. zkSync Era: Choosing the Right Foundation
A detailed comparison of StarkNet and zkSync Era to help you select the optimal ZK-rollup for your subscription-based application, based on technical capabilities, ecosystem maturity, and development requirements.
| Key Factor | StarkNet (Cairo) | zkSync Era (Solidity/Vyper) |
|---|---|---|
Native Language & VM | Cairo (custom VM) | Solidity/Vyper (EVM-compatible) |
Developer Onboarding | Steeper learning curve | Familiar for Ethereum devs |
Proving System | STARKs (scalable, no trusted setup) | SNARKs/STARKs (zkEVM, trusted setup) |
Transaction Cost (Typical) | Lower for complex logic | Competitive, varies with opcode |
Time to Finality | ~12 hours (challenge period) | ~1 hour (challenge period) |
Ecosystem & Tooling | Growing, unique toolchain | Mature, extensive EVM tools |
Native Account Abstraction | Yes (at protocol level) | Yes (powerful SDK support) |
Our Development Timeline | 6-10 weeks (specialized) | 4-8 weeks (accelerated) |
Ideal Use Case | Compute-heavy, novel logic, gaming | Fast migration, DeFi, multi-chain apps |
how-we-deliver
PREDICTABLE & TRANSPARENT
Our Development & Delivery Process
A structured, client-focused methodology designed to deliver secure, production-ready subscription contracts on StarkNet and zkSync with minimal risk and maximum transparency.
01
Discovery & Architecture Design
We begin with a deep technical workshop to define your business logic, tokenomics, and integration points. We deliver a detailed technical specification and architecture diagram for your review.
2-3 days
Workshop Duration
1
Approved Spec Deliverable
02
Smart Contract Development
Our certified Cairo/Solidity developers build your contracts using battle-tested patterns from OpenZeppelin and our internal libraries. Every line is written for gas efficiency and security from day one.
100%
Custom Code
OpenZeppelin
Security Foundation
03
Comprehensive Security Audit
All contracts undergo rigorous internal review followed by a formal audit from a leading third-party firm like CertiK or Quantstamp. We resolve all critical/high issues before deployment.
2-Layer
Audit Process
0 Critical
Issues at Launch
04
Testnet Deployment & Simulation
We deploy to StarkNet Goerli/zkSync Sepolia and execute a full suite of integration tests, simulating real user flows and edge cases to ensure flawless performance.
> 95%
Test Coverage
Full Flow
User Simulation
05
Mainnet Launch & Monitoring
We manage the production deployment, configure initial parameters, and implement 24/7 monitoring with alerting for contract events, balance thresholds, and anomalous activity.
< 1 hour
Deployment Window
24/7
Initial Monitoring
06
Documentation & Knowledge Transfer
You receive complete technical documentation, admin guides, and a handover session with our lead engineer. We ensure your team is fully equipped to manage and iterate on the system.
Complete
API & User Docs
2 Hours
Handover Session
Choose the right plan for your project's scale and security requirements
Development Tiers & Deliverables
Compare our structured service packages for StarkNet and zkSync subscription contract development, from initial audit to full-scale deployment and maintenance.
| Feature / Deliverable | Starter | Professional | Enterprise |
|---|---|---|---|
Smart Contract Audit & Review | |||
Gas Optimization Report | |||
Deployment to Testnet | |||
Mainnet Deployment Support | |||
Integration Testing Suite | |||
Post-Deployment Monitoring (30 days) | |||
24/7 Production Monitoring & Alerts | |||
SLA for Critical Issue Response | 48h | 24h | 4h |
Dedicated Technical Account Manager | |||
Custom Feature Development | |||
Estimated Delivery Timeline | 2-3 weeks | 4-6 weeks | 8+ weeks |
Starting Price | $15,000 | $45,000 | Custom Quote |
StarkNet & zkSync Subscriptions
Frequently Asked Questions
Get clear answers on our development process, security, and timelines for building subscription models on StarkNet and zkSync.
A standard subscription contract deployment on StarkNet or zkSync takes 2-4 weeks from specification to mainnet launch. This includes design, development, testing, and audit preparation. Complex logic, multi-chain deployments, or custom tokenomics can extend this timeline, which we outline in a detailed project plan before engagement.
ENQUIRY
Get In Touch
today.
Our experts will offer a free quote and a 30min call to discuss your project.
NDA Protected
Confidentiality24h Response
Time to ValueDirectly to Engineering Team
No Sales Fluff10+
Protocols Shipped
$20M+
TVL Overall