Blockchain Service

Blockchain Development

We build blockchain systems your business can actually run — smart contracts, permissioned networks, tokenization and Web3 integration, designed, audited and operated end to end. Not a whitepaper. A system that goes live, stays live, and belongs to you.

Public & permissioned chains Audit-first delivery Full source & IP handover
What we build

Blockchain services, from contract to production

Every engagement is scoped around a business outcome — settlement time, traceability, cost per transaction — and delivered by the same team that already builds your apps, websites and infrastructure.

Smart Contract Development

Production-grade contracts written for correctness and gas efficiency: fungible and non-fungible tokens, staking, escrow, vesting, upgradeable proxy patterns and role-based access control.

Solidity · Rust · Foundry · OpenZeppelin

Security Audit & Code Review

Line-by-line manual review backed by static analysis, fuzzing and invariant testing. You get a severity-ranked findings report, fixes applied, and a re-test before anything touches mainnet.

Slither · Mythril · Echidna · Invariant tests

Private & Consortium Networks

Permissioned ledgers for groups of companies that need shared data without shared control: membership design, channel and privacy policy, consensus tuning, node provisioning and disaster recovery.

Hyperledger Fabric · Besu · Quorum · Corda

Token & Digital Asset Issuance

Token design that survives legal and economic review: supply and vesting modelling, multi-signature treasury, distribution mechanics, and the technical readiness required by exchanges and custodians.

ERC-20 · ERC-721 · ERC-1155 · Gnosis Safe

dApp & Web3 Front End

Interfaces normal people can use. Wallet connection, clear transaction states, human-readable errors, gasless transactions through account abstraction, and a path for users who have never held a wallet.

React · Next.js · wagmi/viem · WalletConnect

Wallet, Custody & Payments

Key management that passes an audit: MPC and HSM-backed custody, multi-signature approval flows, stablecoin settlement, and on/off-ramp integration with licensed providers.

MPC · HSM · Multi-sig · Stablecoin rails

Supply Chain Traceability

Item-level provenance from raw material to shelf. QR and NFC tagging, IoT and ERP data ingestion, tamper-evident event history, and a public verification page your customers can actually read.

QR/NFC · IoT gateway · ERP sync · Consumer portal

Integration With Existing Systems

The chain is never the whole system. We build the indexers, event listeners, queues and APIs that connect it to your ERP, CRM, core banking or warehouse software — so operations stay in one place.

The Graph · Chainlink · REST/GraphQL · Kafka
Why blockchain

Why a business would move a process onto a blockchain

Blockchain is worth the effort when several organisations need to agree on the same record and none of them should be able to change it quietly. That is a narrow definition on purpose — and it still covers more of your operations than you might expect.

  • One shared source of truth across partnersSuppliers, banks, logistics providers and auditors read the same ledger instead of reconciling five spreadsheets.
  • Records that cannot be edited after the factAppend-only history with cryptographic proof — the difference between claiming compliance and demonstrating it.
  • Settlement that runs without a middlemanSmart contracts release payment the moment the delivery condition is met, cutting days of manual clearing to seconds.
  • Products you could not offer beforeTokenized assets, fractional ownership, transferable loyalty points and verifiable digital certificates.
  • Proof your customers can check themselvesA scan on the product tells the whole origin story — trust you no longer have to ask people to take on faith.

And when it is the wrong tool

We will tell you before you spend the budget. A blockchain is a poor fit when:

  • One company owns the data and controls every write — a database is faster and cheaper.
  • The records must be deletable on request under privacy rules.
  • No partner outside your organisation ever reads the data.
  • The real problem is process discipline, not verification.

In those cases we build the conventional system instead — and you keep the budget for what actually moves the business.

Technology

The chains and tools we work with

We choose the platform after we understand the requirement — throughput, privacy, cost per transaction, regulatory posture — never the other way round.

Public networks

EthereumBNB ChainPolygon PoS ArbitrumBaseOptimism SolanaAvalanche

Permissioned & enterprise

Hyperledger FabricHyperledger Besu ConsenSys QuorumR3 CordaCosmos SDK

Languages & frameworks

SolidityRustGo TypeScriptFoundryHardhatAnchor

Infrastructure & security

IPFS / ArweaveThe GraphChainlink OpenZeppelinGnosis SafeKubernetesDocker
Where it pays off

Solutions by industry

Six areas where our clients see a measurable return — shorter settlement cycles, fewer disputes, lower audit cost.

Financial services & payments

Cross-border settlement, programmable escrow, trade finance documentation and stablecoin treasury operations with a full audit trail.

→ cross-border payout
→ automated escrow release
→ tokenized fund units

Supply chain & logistics

Shipment and custody events written as they happen, shared with every partner in the lane, with exception alerts instead of email chains.

→ chain-of-custody proof
→ cold-chain compliance
→ dispute resolution

Agriculture & manufacturing

Farm-to-shelf and factory-to-buyer traceability that satisfies export requirements and gives consumers something real to scan.

→ origin verification
→ export documentation
→ anti-counterfeit tagging

Real estate & asset tokenization

Fractional ownership, transparent ownership records, automated distribution of rental income, and transfer rules enforced in code.

→ fractional ownership
→ automated distributions
→ compliant transfer rules

Healthcare & records

Consent management and record integrity: sensitive data stays off chain, while the proof that it was not altered stays on it.

→ patient consent registry
→ document integrity proof
→ pharmaceutical tracking

Education & government

Diplomas, licences and permits issued as verifiable digital certificates that any employer or agency can check in seconds without calling you.

→ verifiable diplomas
→ licence registries
→ public procurement records
How we deliver

Six stages, each one linked to the last

Every stage ends with something you can inspect — a document, a demo, a report. Nothing moves forward until the previous stage is signed off, and you can stop at any block.

Block 01

Discovery & feasibility

We map the process, identify who needs to trust what, and decide honestly whether a blockchain belongs here. Chain selection and a cost-per-transaction model come out of this stage.

1–2 weeks→ feasibility report
Block 02

Solution architecture

What lives on chain and what stays off it, consensus and permission model, key management, upgrade path, and a written threat model reviewed with your security team.

2 weeks→ architecture pack
Block 03

Proof of concept

A working slice on a test network — real contracts, real transactions, a clickable interface. Enough to demo to a board and to prove the numbers hold.

2–4 weeks→ testnet demo
Block 04

Full build

Contracts, back-end services, indexers, dApp and integrations built in two-week increments, with a running environment you can use after every one.

6–16 weeks→ release candidate
Block 05

Audit & hardening

Internal audit, fuzzing and invariant testing, external audit coordination where the value at risk justifies it, plus a full dry run on a forked network.

2–3 weeks→ audit report
Block 06

Launch & operations

Mainnet deployment, node and contract monitoring, incident response, and a documented handover of code, keys and infrastructure to your team.

ongoing→ live system
15+Years of experience
1,000+Projects delivered
30+Passionate team members
Engagement models

Three ways to start with us

Start small if the case is unproven, or bring us in as your blockchain team if it already is. Pricing is quoted after discovery, so you never pay for scope we have not yet understood.

Proof of Concept Sprint

4 weeks · fixed fee

For teams who need to know whether this works before committing a budget.

  • Feasibility assessment and chain selection
  • Architecture document
  • Working prototype on a test network
  • Cost and throughput projection
  • Go / no-go recommendation in writing
Scope a sprint

End-to-End Build

3–6 months · milestone-based

Full delivery of a production system, from architecture through mainnet launch.

  • Everything in the PoC Sprint
  • Smart contracts and back-end services
  • dApp or admin interface
  • Integration with your existing systems
  • Security audit and remediation
  • Deployment, monitoring and handover
Request a proposal

Dedicated Blockchain Team

Monthly · 2–6 engineers

For products with a roadmap, where the work does not end at launch.

  • Named engineers, your sprint cadence
  • Protocol, back-end and front-end coverage
  • Node operations and 24/7 monitoring
  • Contract upgrades and incident response
  • Scale the team up or down each month
Discuss a team
Why CTG

A software partner that happens to do blockchain well

CTG has been building mobile apps, websites, hosting and management software for years. Blockchain is an extension of that work — which is exactly why our systems ship instead of stalling at the pilot.

01

One partner for the whole product

The chain, the API, the mobile app, the admin panel and the hosting come from the same team. No integration gap between three vendors blaming each other.

02

Security is a stage, not an afterthought

Threat modelling starts in architecture and audit is a named phase with its own deliverable. Contracts are immutable once deployed — we treat them that way from day one.

03

You own everything

Repositories, deployment scripts, documentation, keys and infrastructure are transferred to your accounts. No hidden dependency on us to keep the system running.

04

Honest scoping

We say no to projects that do not need a blockchain, and we say so during discovery rather than after the invoice. It costs us work and earns us the next three projects.

Questions

What clients ask us first

How do I know whether my business actually needs a blockchain?

Ask one question: does more than one organisation need to trust the same record, without any single one of them being able to change it quietly? If yes, a blockchain earns its cost. If the answer is no, a well-built database will be faster and cheaper — and we will tell you so during discovery, before you commit a budget.

Public chain or private network — which should we choose?

Public networks give you open verification and access to existing liquidity and wallets, at the cost of transaction fees and full transparency. Permissioned networks like Hyperledger Fabric give you privacy, control over membership and near-zero transaction cost, but you operate the infrastructure. Regulated industries and consortium projects usually go permissioned; consumer-facing assets and tokens usually go public. Many of our systems use both.

How long does a project take, and what does it cost?

A proof of concept runs four weeks at a fixed fee. A production system typically takes three to six months depending on integration scope and audit requirements. We quote only after discovery, because a quote given before we understand your data flows is a guess — and guesses get corrected later at your expense.

Who controls the signing keys?

You do. We design the key management scheme — multi-signature approval, MPC or HSM-backed custody depending on the value at risk — and we operate it during development on test networks only. Production keys are generated by your team in a ceremony we document, and never leave your control.

What about the regulatory situation in Vietnam?

Building and operating blockchain infrastructure, traceability systems and enterprise ledgers is straightforward. Issuing tokens or handling digital assets touches rules that are still developing, so we structure those projects with your legal counsel from the architecture stage and build the compliance controls — transfer restrictions, identity checks, reporting — directly into the contracts. We are engineers, not your lawyers, and we work alongside them rather than around them.

Our customers have never used a crypto wallet. Is that a problem?

No — and it is the most common reason blockchain products fail. We build with account abstraction and sponsored transactions so users sign in with an email or a phone number, never see a seed phrase, and never pay a gas fee. The chain runs underneath; the experience stays a normal app.

Get started

Tell us what you are trying to prove

Send us the process you want to put on chain. Within two working days you will get a written first opinion — whether blockchain fits, which platform we would pick, and a rough timeline. No obligation, no sales call required.

We use your details only to answer this enquiry. Prefer email? Write to [email protected] or call 0912.80.50.86.