Smart Contract Development
Audited, upgradeable EVM contracts for settlement, treasuries, and tokenized assets — written for clarity, tested for adversarial conditions.
Boutique engineering lab
Production-grade blockchain & backend engineering.
We help startups and fintechs build secure, scalable software for blockchain, payments, prediction markets, and financial infrastructure.
Specialized in
- EVM
- Stablecoins
- Custodial Wallets
- Ledgers
settlement-pipeline.ts healthy
01
API Gateway
REST · idempotent
02
Queue Worker
retries · backoff
03
Internal Ledger
double-entry
04
On-chain Settlement
Polygon · USDC
99.98%
uptime
exactly-once
processing
0 drift
reconciliation
Services
Engineering across the full blockchain stack
From smart contracts to the backend systems that keep money moving — we build the layers that financial products depend on.
Blockchain Backend APIs
Typed, well-documented services that abstract chain complexity behind reliable REST and event-driven interfaces.
Custodial Wallet Infrastructure
Secure key management, deterministic address derivation, and hardened deposit and withdrawal flows with full auditability.
Stablecoin Payment Flows
On-chain USDC/USDT deposits, transfers, and off-ramps with idempotent processing and reconciliation built in from day one.
Prediction Market Infrastructure
Multi-tenant market engines with spreads, fees, order handling, settlement, and operator controls — end to end.
EVM Integrations
Robust Viem-based integrations across Polygon and Base — nonce management, gas strategy, and resilient confirmation handling.
Ledger & Settlement Systems
Double-entry internal ledgers with balance integrity, settlement batching, and continuous on-chain reconciliation.
Technical Architecture Consulting
Pragmatic system design for financial products: data models, queues, failure modes, and a roadmap your team can own.
Why Arthel Labs
Built like financial infrastructure should be
We bring the discipline of production fintech systems to blockchain — the unglamorous engineering that keeps balances correct and funds safe.
Security-first engineering
Threat modeling, least-privilege access, and defensive contract design are defaults, not afterthoughts. Money-handling code is reviewed like money-handling code.
Scalable backend architecture
Stateless services, queue-based processing, and clear domain boundaries — systems that grow with throughput instead of buckling under it.
Real financial-product experience
We have shipped custodial wallets, ledgers, and settlement engines in production — not prototypes. We know where these systems break.
Correctness under failure
Idempotency, retries with backoff, and exactly-once semantics so partial failures never become lost funds or double spends.
Queue-based processing Idempotency Retries & backoff Observability EVM integrations Polygon / Base USDC / USDT flows Upgradeable contracts Ledger & reconciliation
Case Studies
Systems we've shipped to production
Selected work building the infrastructure behind blockchain-native financial products.
01
Prediction Market Infrastructure
Multi-tenant prediction market platform with wallet custody, internal ledger, blockchain settlement, market imports, spreads, fees, and operator controls.
- Polygon
- USDC
- USDT
- NestJS
- Go
- Redis
- PostgreSQL
- Viem
- Smart Contracts
02
Stablecoin Payment Gateway
Infrastructure for stablecoin deposits, custodial wallets, on-chain transfers, off-ramp flows, reconciliation, idempotent processing, and financial audit trails.
- USDT
- Polygon
- Wallets
- Ledger
- Queues
- Webhooks
- Reconciliation
03
Smart Contract Systems
Upgradeable EVM contracts for prediction markets, treasuries, tokenized shares, fee management, and secure settlement flows.
- Solidity
- Hardhat
- OpenZeppelin
- UUPS
- EVM
- Security
Tech Stack
A deliberate, battle-tested toolset
We favor mature, well-understood technologies over novelty — the kind you can run in production for years.
Smart Contracts
- Solidity
- Hardhat
- OpenZeppelin
- Viem
Backend
- TypeScript
- Node.js
- NestJS
- Go
Frontend
- Vue
- Nuxt
- Tailwind CSS
Data & Infra
- PostgreSQL
- Redis
- Docker
Chains
- Polygon
- Base
Process
How we work
A focused, low-overhead engagement model designed for momentum and clarity.
- 01
Discover
We map the problem, constraints, and threat surface — aligning on scope, risks, and what success actually means before any code is written.
- 02
Architect
We design the data model, services, contracts, and failure modes up front, so the system is sound by construction rather than patched later.
- 03
Build
We ship in tight increments with tests, observability, and code review — production-grade from the first commit, not retrofitted at the end.
- 04
Launch & Iterate
We deploy, monitor, and harden under real load, then iterate with your team and hand over systems they can confidently own.
About
A lab, not an agency
Arthel Labs is a software engineering lab focused on building reliable blockchain and backend infrastructure for ambitious digital products.
Founded by Raphael Rêgo, a senior software engineer specialized in backend systems, EVM integrations, smart contracts, custodial wallets, payment flows, and financial infrastructure.
RR
Raphael Rêgo
Founder · Senior Software Engineer
Focus areas
- Backend systems
- EVM integrations
- Smart contracts
- Custodial wallets
- Payment flows
- Financial infrastructure
Contact
Ready to build your next blockchain product?
Tell us what you're building. We'll reply with a clear, honest read on scope, approach, and how we can help.