Integrating Blockchain into the application | Tan Phat Digital

The shift from traditional Web2 architecture to decentralized models is no longer a simple experimental trend but has become a strategic requirement for businesses. According to analysis from the team of experts at Tan Phat Digital, businesses looking for transparency, security and high data resilience in the digital economic era of 2025 need to consider this as a focus. Integrating blockchain into existing applications is not simply about installing a new layer of technology, but a process of restructuring the mindset of digital trust, replacing human- and institution-based trust mechanisms with immutable mathematical protocols. This report deeply analyzes aspects from the decision model to technical implementation barriers, operating costs and legal risks in the current market context.

Decision architecture and trust philosophy in system integration

The starting point of every successful blockchain integration project is not the choice of protocol but determining whether the technology can truly solve the business problem. The Wüst-Gervais model provides a rigorous frame of reference for classifying real business needs. A system should only consider integrating blockchain if and only if it faces the challenge of coordinating data between multiple parties that do not trust each other, requires a permanent record, and lacks a trusted third party to act as arbiter.

If an application can work effectively with a centralized database and the entity that manages that data remains fully trusted by the stakeholders, introducing blockchain will only introduce complexity not necessary. However, in areas such as decentralized finance (DeFi), product traceability and document management, blockchain becomes an essential infrastructure to ensure data integrity.

Comparison of Traditional Database (Web2) and Decentralized Blockchain (Web3):

Trust Model: Web2 is based on a central entity (Authority); Web3 is based on the consensus algorithm (Math).
Data recording capabilities: Web2 can be modified and deleted (CRUD); Web3 is append-only.
Transparency: Web2 is limited, access rights are granted by the owner; Web3 is public or auditable on the ledger.
System reliability: Web2 has a centralized weakness (Single Point of Failure); Web3 is highly fault-tolerant, distributed throughout the network.
Processing performance: Web2 is very high, millisecond latency; Web3 is lower due to consensus validation process.
Infrastructure costs: Web2 is low, easy to predict; Web3 is high, dependent on gas fees and network resources.

The core difference lies in how data is protected. In traditional databases, security depends on firewall barriers and administrator permissions. In blockchain, immutability is guaranteed by a cryptographic hash function. Once a transaction is confirmed into a block, changing any past data requires recomputing all subsequent blocks, a task that is energy and time impossible for large networks.

Integrated Technical Approach: APIs, SDKs, and Blockchain-as-a-Service (BaaS)

Integrating blockchain into existing apps does not require organizations to completely replace legacy infrastructure (Legacy Systems). Instead, businesses often use an intermediary layer (Middleware) to create a data bridge.

Integration via API and the role of indexers (Indexers)

Blockchain API integration is the most popular method today. API services from vendors like Alchemy, Infura or SubQuery act as "gateways" that allow Web2 applications to communicate with the blockchain network without needing to operate a full node. This saves significant bandwidth and storage resources.

Indexers like SubQuery solve an important problem: blockchain is not inherently designed to query data in a flexible way like SQL. When an application needs to get a list of all transactions of a user or filter events from a smart contract, the indexer scans all on-chain data, organizes them into a structured database and provides GraphQL endpoints for the application to quickly query.

Technical Integration Implementation Roadmap

The process of implementing blockchain integration into an app usually follows a strict 5-step process to ensure stability:

Network Selection: Decide between Ethereum for highest security, Solana for maximum speed, or Layer 2 networks like Polygon for cost optimization.
Node Connectivity: Use API providers or deploy a private node if privacy is required. high.
Data structure via Indexer: Set up mappings to filter and restructure raw data from the blockchain into the application database.
Develop interaction layer (Web3 integration): Build communication functions to sign transactions (signing), manage wallets and track transaction status on chain.
Testing and Deployment: Use testnets to simulate network load, check contract errors and optimize gas before going live.

See more: What is a Smart Contract?

Blockchain-as-a-Service (BaaS): Solution for large enterprises

For organizations that need tight control but do not want to manage the technical complexity of the infrastructure layer, BaaS is the top choice. Platforms such as Alibaba Cloud BaaS, AWS, or specialized providers such as Kaleido and BlockApps provide ready-made templates for deploying blockchain networks. BaaS helps businesses focus on developing business logic (Smart Contracts) instead of worrying about node synchronization, network layer security or protocol updates.

The outstanding advantage of BaaS is the ability to integrate with other cloud services such as storage systems, data analysis and identity management (IAM), creating a unified ecosystem for businesses.

Hybrid data management strategy: On-chain and Off-chain

One of the most costly mistakes when integrating blockchain into current applications is trying to store all user data directly on the chain (On-chain storage). Tan Phat Digital's research shows that the Hybrid Data Model is the key to achieving a balance between transparency and economic efficiency.

Hash Anchoring

Instead of storing a PDF document file or a high-resolution image on the blockchain, developers use the "Hash Anchoring" technique. Original data is stored in off-chain systems such as IPFS, Arweave or traditional SQL databases. A cryptographic hash function (e.g., SHA-256) is then generated from that data file. Only this hash code is recorded on the blockchain.

The logic of this mechanism is based on the property of the hash function: $H(x) = y$. If data $x$ is changed by even one bit, the hash code $y$ will change completely. When authentication is needed, the system will recalculate the hash code of the current data and compare it with the hash code that has been permanently saved on the blockchain.

Data storage classification:

On-chain storage: Characteristics of absolute transparency, high cost, immutability. Consistent with account balances, ownership, voting results.
Off-chain storage (Decentralized): Uses IPFS/Filecoin, low cost, distributed. Suitable for NFT files, medical records, large legal documents.
Off-chain storage (Centralized): Using Cloud/SQL, high speed, easy to modify. Suitable for user settings, system logs, temporary data.

Adopting this model is especially important to comply with privacy regulations such as GDPR. By saving personal information off-chain and only storing the hash on-chain, businesses can delete the original data off-chain when required without breaking the blockchain structure.

Revolutionizing user experience (UX) through Account Abstraction (ERC-4337)

The biggest barrier preventing widespread adoption of blockchain-integrated applications is the complexity of wallet management. The concept of Account Abstraction (AA) and the ERC-4337 standard have completely changed this landscape, allowing Web3 integration to achieve smoothness equivalent to Web2.

From EOA wallet to Smart Contract wallet

In the traditional model (EOA), users must preserve the seed phrase themselves. Account Abstraction turns a user account into a smart contract (Smart Contract Wallet), allowing complex logic to be programmed right on that account.

Breakthrough features of AA:

Gasless Transactions:The application can sponsor gas fees for new users through the Paymaster contract.
Pay fees with Tokens any: Users can pay gas fees with stablecoins like USDC.
Social Recovery: Regain wallet access via email or Google account.
One-touch transactions (Session Keys): Approve a "session" to make multiple transactions without signing each step.

Economic analysis and development costs in 2025

Integrating blockchain into an existing app is a big financial decision. Development costs include programmer salary and specific infrastructure maintenance fees.

Web3 expert salary in 2025 (USD/year):

Solidity Developer: $125,000 – $200,000 (Skills: Ethereum, EVM, Security).
Rust Developer: $140,000 – $210,000 (Skills: Solana, Polkadot, High performance).
Smart Contract Auditor: $150,000 – $250,000 (Skills: Formal Verification, Exploits).
Core Protocol Engineer: $150,000 – $220,000 (Skills: Cryptography, Distributed Systems).

In Vietnam, the salary for blockchain programmers ranges from $40,000 to $80,000 per year, which is the optimal cost choice for businesses.

Project budget by scale:

NFT Marketplace MVP: About $48,000 (8 weeks of distribution) development).
DeFi Protocol (Lending/Borrowing): About $212,000 (4 months of development).
Cross-chain Bridge: About $432,000 (6 months of development).

Comparing the performance and scalability of Blockchain networks

When deciding to integrate In case, network choice directly affects application performance.

Performance analysis of popular networks in 2025:

Ethereum (Layer 1):Throughput 15–30 TPS; Cost $1–$50; Confirmation time 12–15 seconds; Highest security.
Solana: Throughput 2,000–4,000+ TPS; Extremely low cost (<$0.001); Confirmation time 400ms; Medium security.
Polygon (L2/Sidechain): Throughput 7,000–10,000 TPS; Low cost (<$0.01); Confirmation time 2 seconds; Inheriting security from Ethereum.
Arbitrum (Layer 2): Throughput ~40,000 TPS; Low cost (<$0.1); Confirmation time <1 second; Inheriting security from Ethereum.

Security risks and vulnerabilities of legacy Web2 infrastructure

Blockchain is inherently secure, but the "junction" between Web2 and Web3 is often the weakest point. Research shows that 95% of Web3 developers are concerned about malicious attacks inherited from Web2 infrastructure.

Supply chain vulnerabilities: Attackers can take control of frontend libraries such as ethers.js to change the wallet address to receive funds right in the browser.
RPC risks: Dependence on wallets Intermediate RPC nodes or centralized cloud services like AWS create "centralized weaknesses" in decentralized systems.

Practical Applications and Lessons from Failed Projects

Success in the Supply Chain

Walmart has reduced mango traceability time from 7 days to 2.2 seconds thanks to blockchain. BMW and Ford also integrated this technology to ensure ethical cobalt mining, meeting ESG standards.

Failure lessons from TradeLens

The TradeLens project closed at the end of 2022 due to lack of stakeholder participation. Competitors do not want to join a platform dominated by a single entity (Maersk). The lesson is: blockchain is only strong when there is neutral cooperation.

Legal Framework and Sandbox Mechanism in Vietnam 2024 - 2025

Vietnam is making a strong legal transformation to support blockchain applications.

Legal Roadmap in Vietnam:

May 2024 (Decree 52/2024/ND-CP): Regulations on non-cash payments, creating a premise for electronic money.
July 1, 2025 (Decree 94/2025/ND-CP): Officially operating the testing mechanism (Sandbox) for Fintech in the banking sector goods.
October 1, 2025 (Law on Science, Technology and Innovation): Allows testing of new technology (Sandbox) for up to 6 years.
2025 (Law on Digital Technology Industry): Officially defines and classifies "Digital Assets".

Frequently Asked Questions (FAQ)

Blockchain should not be used if the application only serves a single party, data needs to be changed/deleted frequently, or if a traditional centralized database is sufficient to meet the needs with lower cost and higher performance.

What is the current salary of a blockchain programmer in Vietnam?
The average salary is about 2,241 USD/month (about 55 million VND). Senior positions or security experts can receive from 30 to 100 million VND/month depending on qualifications.

How to solve the problem of gas fees for users without knowledge of crypto?
Use the Account Abstraction standard (ERC-4337) with the "Paymaster" feature. This allows businesses to self-fund gas fees for users or allows users to pay fees with the stablecoin they are trading.

Is data on blockchain really more secure than centralized databases?
Blockchain is more secure against tampering thanks to its distributed consensus mechanism, but it does not encrypt data by default. If not carefully designed, public data on the chain can expose sensitive information.

How to store large videos or photos without spending too much on gas?
Use a Hybrid model: store the original file on decentralized networks like IPFS or cloud (AWS S3) and store only the hash of that file on the blockchain to validate its integrity.

The main difference between Ethereum and Solana when choosing an integration platform is What?
Ethereum prioritizes absolute security and high decentralization, but gas fees are expensive and speed is slow. Solana prioritizes extremely high performance (huge TPS) and super cheap transaction fees, suitable for mass consumer applications.

How long does it take to deploy a basic blockchain integration project?
A simple MVP version (like NFT Marketplace) usually takes about 8 weeks. More complex systems such as financial protocols (DeFi) can take 4 to 6 months.

Who is Blockchain-as-a-Service (BaaS) suitable for?
BaaS is suitable for large businesses that need to quickly deploy infrastructure without wanting to manage the complexity of network nodes (nodes), helping to focus resources on developing business logic and smart contracts .

How to comply with the right to be forgotten (GDPR) when blockchain cannot delete data?
Businesses should store personal identification information off-chain and only store hash codes (Hash) on-chain. When you need to delete, you simply delete the off-chain data, causing the on-chain hash code to become a meaningless string of characters that cannot be traced back.

What is the biggest risk when connecting existing Web2 infrastructure to the Web3 protocol?
The risk lies in intermediate connection points (RPC) and frontend libraries. Attackers can insert malicious code into libraries like ethers.js to change the user's wallet address to receive money right in the browser.

What is Vietnam Blockchain Multi-Chain Service Network (VBSN)?
VBSN is a national blockchain infrastructure fully owned by Vietnam with the core technology, integrated on the VNeID application to serve traceability and online public services.

How does Account Abstraction (ERC-4337) improve user experience?
It allows to log in to the application using email/Google instead of seed phrase, restore accounts via friends (social recovery), and perform multiple transactions with just one confirmation.

Sandbox mechanism for Fintech in Vietnam (Decree 94/2025) allows What to test?
This mechanism allows businesses to test new business models such as peer-to-peer lending (P2P lending), credit scoring and data sharing via Open API in a safe legal corridor.

Why did IBM and Maersk's TradeLens project fail despite the technology being so good?
The failure was mainly due to governance issues: competitors did not trust a platform dominated by one party. This shows that blockchain needs a neutral collaborative ecosystem to succeed.

Integrating Blockchain into an existing app depends on the balance between the need for transparency and the ability to tolerate costs. Tan Phat Digital recommends that businesses thoroughly evaluate business problems before deploying.

Recommended action:

Valuation: Only integrate if immutability or multi-party transparency is needed.
Hybrid Storage: Keep large data off-chain, store hash code on-chain to maximize Prioritize costs.
Prioritize Account Abstraction: Eliminate wallet and gas fee barriers to retain users.
Choose Layer 2:Prioritize Arbitrum or Polygon for mass consumer applications.
Join Sandbox: Actively register for the State Bank's testing mechanism to operate safely.

Blockchain, when intelligently integrated with advice from experts like Tan Phat Digital, will create a solid foundation of trust, opening up new business models in the economy Web3.