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60+ Blockchain Interview Questions you must know (2023 update)

Introduction

Blockchain technology has excellent potential to disrupt and change the way we do business.  The blockchain industry is expected to increase from $7.18 billion in 2022 to $163.83 billion in 2029, with a CAGR (compound annual growth rate) of 56.3%. Because of its promising future, and the new positions being created daily, it is important to get professional blockchain certification training and prepare yourself for the blockchain interview to land your dream job. In this blog, we have discussed the top blockchain interview questions and answers that can help you crack your interview. 

For ease of understanding, we have categorized these blockchain interview questions into the following:

  • Blockchain Interview Questions for Fresher 
  • Blockchain Interview Questions for Experienced

Let's get started with

Blockchain Interview Questions for Fresher

1. What is the fundamental principle of blockchain technology?

It makes it possible to share information across users without it being copied.

2. What various blockchain types are there?

There are three types of blockchains:

  • Public
  • Private
  • Public

3. How does the Blockchain approach to identify blocks?

 Every block in this online ledger essentially consists of transaction information, a time stamp, and a hash reference that serves as a connection to the block that comes before it. 

This is one of the most frequently added topics in the blockchain interview questions and answers list. 

4. What are the Block Identifiers?

This is among the most commonly asked blockchain interview questions.

Blocks in the blockchain can be recognized by their block height and block header hash. Going through the Blockchain Tutorial Guide can help you understand such basic topics. 

5. Why are smart contracts useful, and what are they?

Blockchain-based smart contracts are lines of code that run automatically. They specify the guidelines for how a transaction must be handled between the parties under particular circumstances. It functions essentially as a blockchain network's digital contract.

6. How does a dApp vary from a smart contract and what is a dApp?

DApps are used to communicate with a smart contract or a blockchain network. It is a decentralized program that employs blockchain technology to carry out a specific function or feature.

Smart contracts provide the procedures to be followed in a transaction between two peers. When the required condition is satisfied, they self-execute.

7.How does a blockchain add blocks?

This is among the most commonly asked blockchain interview questions.

Mining is the method by which blocks are added to the blockchain. When a transaction is made, the accompanying block is created and must first pass validation by at least 51% of the network's nodes. Once the block has been verified, it is broadcast to the whole network and added to the blockchain.

8. What are Merkle Trees? Describe their idea.

Binary hash trees are another name for the Merkle trees data structure. Verifying whether a transaction can be included in a block or not is helpful. All transactions are hashed using the correct algorithms. The non-leaf node is a hash of its previous hashes, and each leaf node is a hash of the transaction (child hashes). 

This is one of the most frequently added topics in the blockchain interview questions and answers list. 

9. What kinds of records are compatible with a blockchain?

The Blockchain technique does not place any limitations on the kind of records that can be kept. Blockchain is being used by businesses to secure various kinds of documents. Transactions are logged in a distributed digital ledger with blockchain technology.

10. What is the system dependent upon?

The network's nodes and network servicing protocol are both essential to the operation of the system.

11. Describe rfd3.

A block is verified using a data structure called a Merkel Tree. It has the shape of a binary tree and contains the block's individual cryptographic hashes. Each leaf node of a Merkle tree is a hash of a block of transactional data, and each non-leaf node is a hash of its leaf node. This structure is similar to that of a binary tree.

12. What is cryptography?

This is among the most commonly asked blockchain interview questions.

With the use of a hash function, blockchain leverages cryptography to protect users' identities and ensure that transactions are completed securely.

Data is encrypted and decrypted using public and private keys in cryptography. A public key on the Blockchain network can be distributed to all Bitcoin users, while a private key is kept secret with the users.

13. What is a Coinbase transaction?

It's a one-of-a-kind bitcoin transaction that the miners produced. It is utilized by miners to obtain the block reward. This transaction also includes the sending of the transaction fees that miners have accrued.

This is one of the most frequently added topics in the blockchain interview questions and answers list. 

14. What is a blind signature?

In cryptography, a blind signature is a type of digital signature in which the contents of the communication are hidden before they are signed or taken into account.

15. How Does Secret Sharing Work?

This is among the most commonly asked blockchain interview questions.

One of the main techniques for ensuring data security in the blockchain is secret sharing. This method divides private or confidential information into smaller units and transmits them to network users. For participants that receive a share of the secret, the original information is disclosed.

16. What does DAO mean?

Decentralized Autonomous Organization is what the acronym stands for. It is a decentralized organization that also functions autonomously. It is represented by rules that are transparent, regulated by shareholders, and independent of the federal government and are encoded as computer programs.

17. What does "Coinbase transaction" mean?

This is among the most commonly asked blockchain interview questions.

The first transaction in a block is a Coinbase transaction. It is a special kind of bitcoin transaction that a miner can produce. The block reward for their labor is collected by the miners using it, and any additional transaction fees are also transmitted in this transaction.

18. Describe a 51% attack.

A miner or group of miners seeking to control more than 50% of a network's mining power, computational power, or hash rate is known as a "51 percent attack" on a blockchain network.

19. What is a consensus algorithm? 

The consensus algorithm is a technique for reaching an agreement on a data modification across a system or distributed network.

20. Describe blind signature. 

In cryptography, a blind signature is a type of digital signature in which the contents of the communication are hidden before they are signed or taken into account.

21. Where is a blockchain stored?

The blockchain can be kept in a database or as a flat file.

22. List a few of the most widely used platforms for building blockchain apps.

This is among the most commonly asked blockchain interview questions.

The following are some of the well-liked blockchain development platforms:

  • Quorum
  • Ripple
  • R3 Corda
  • Ethereum
  • Hyperledger Sawtooth

Do you wish to know the earning potential in blockchain before entering the field? Here is the complete Blockchain Developer Salary Guide. 

23. What is Mining?

Mining, as it relates to blockchain technology, is the process of adding transactions to a huge distributed public ledger by demonstrating to the network that a block that has been generated is genuine.

24. How would you describe blockchain technology to a person who has never heard of it?

This is among the most commonly asked blockchain interview questions.

A distributed ledger called a blockchain uses cryptography to encrypt and store transactional data as immutable or non-modifiable entries, or "blocks," in a database.

25.  How are blocks recognized?

A block's block height and block header hash serve as indicators.

26. Can the data in a block be changed?

This is among the most commonly asked blockchain interview questions.

You cannot change the data within a block.

27. Which kinds of records are included in the blockchain database?

The records in a blockchain database might be of two different sorts.

  • Transactional Records
  • Block Records

28.  Describe a ledger.

A ledger is a continuously expanding file. All of the exchanges between two parties on the blockchain network are permanently recorded by it.

29.  Exist any network-specific prerequisites for implementing Blockchain technology in a company?

Blockchain can be used on any network without any network-specific requirements. However, the network must follow specified protocols and be peer-to-peer.

30. What constitutes the blockchain ecosystem's main components?

The blockchain consists of four main components:

  • Joint ledger
  • Application node
  • Online application
  • Unanimous algorithm

Blockchain Interview Questions for Experienced

31. How are blocks connected on a blockchain?

Each block on the blockchain is connected to the block before it, or all of the blocks are connected in reverse order.

32. What cryptographic algorithm is employed by the blockchain of bitcoin?

This is among the most commonly asked blockchain interview questions.

Cryptographic algorithms used by different blockchains vary. The SHA256 Hashing algorithm is used by the Bitcoin Blockchain.

33. Does the blockchain really only allow for one parent block every block?

It is accurate to say that a parent block is impossible in a blockchain. In the blockchain, every block is independent. 

34. What does the blockchain development term “trapdoor function” mean?

A trapdoor function is a one-way function, making it simple to calculate in one direction but challenging to calculate in the other unless you have specialized knowledge.

35. What specific knowledge do you have in executive accounting?

This is among the most commonly asked blockchain interview questions.

A unique form of accounting called executive accounting is created specifically for businesses that provide services to customers.

36. What distinguishes Wei and Ether from one another?

Like cents to dollars or pennies to pounds, wei is a unit of measurement. 1 ETH equals 1018 Wei

37. How can I communicate with a network?

You can use a wallet or a DApp, respectively.

38. Which RPCs may you employ to establish a network connection with a geth client?

The JSON-RPC and WS-RPC protocols can be used to establish a network connection with a geth client. Only clients running on the same machine can be connected to using IPC-RPC. 

Do not forget to check this guide on Top Blockchain Tools to ace your coming blockchain interview. 

39. Describe Metamask.

This is among the most commonly asked blockchain interview questions.

Metamask is a browser extension that makes it simple to communicate with Ethereum networks.

40. What is required by the EVM to operate a Smart Contract?

It requires the byte code for the contract, which is produced during the compilation of a higher-level language like Solidity.

41. In a peer-to-peer (P2P) network, how does peer discovery operate?

There is no central server, so when a new node boots up, it has no knowledge of the network. Typically, developers include a list of trusted nodes that can be utilized for initial peer discovery directly in the code.

42. How do you assess the needs for blockchain development?

Tests a candidate's ability to combine personalized needs and experience working together on blockchain development projects.

43. How would you introduce the features of blockchain applications to your sales team?

This is among the most commonly asked blockchain interview questions.

Evaluates the candidate's understanding of training techniques and awareness of the importance of explaining technical concepts in terms that end users can understand.

44. What are the major methods through which you guarantee secure online transactions?

Demonstrates the candidate's understanding of blockchain technologies and cryptography as well as their proficiency with digital transaction security and user identity protection.

45.  How do you keep up with the most recent developments and trends in your industry?

Evaluates a candidate's understanding of the resources that are available, such as the IEEE Blockchain Community, which offers beneficial networking and training opportunities.

46.  What was the most challenging blockchain development project you've worked on?

This is among the most commonly asked blockchain interview questions.

Shows the breadth of the applicant's knowledge and experience in blockchain development, as well as their capacity for teamwork.

47. What are private blockchains?

Private (or consortium) blockchains are those on which the consensus is decided by a small, closed group of players who have some interest in sharing data and processes, rather than by an open community of anonymous, financially motivated validators (the miners). a group of banks, as an illustration, or participants in a supply chain.

48. What does Blockchain do?  

A blockchain is a digital, decentralized ledger that records every transaction that occurs on a peer-to-peer network.

49. What do Blockchain confirmations entail?

Bitcoin confirmations, to be precise. A new block is produced and added to the blockchain by the mining process approximately every ten minutes. Any new transactions are verified and recorded in this block. The Bitcoin network is then deemed to have confirmed the transactions.

50. The Blockchain uses a distributed digital ledger to record transactions. What is the system dependent upon?

This is among the most commonly asked blockchain interview questions.

The network's nodes and network servicing protocol are both essential to the operation of the system.

51. Which Blockchain Platforms are Popular for Blockchain Applications?

The list of popular platforms for blockchain-based apps is provided below.

  • IBM Blockchain
  • EOS
  • OpenLedger
  • Corda
  • Ripple Blockchain

Do not miss adding these kinds of blockchain developer interview questions in your revision list when preparing to crack your blockchain intern at first trial. 

52. How is blockchain used by Bitcoin?

A transaction is a value transfer between Bitcoin wallets that is documented in the blockchain. Private keys, often referred to as seeds, are kept in bitcoin wallets and are used to sign transactions and demonstrate mathematically that they originated from the wallet's owner.

53. What Is Public Blockchain?  Give instances.

This is among the most commonly asked blockchain interview questions.

A public blockchain is just that—public. They are totally open, everyone is welcome to read, write, and participate. Blockchain is decentralized, with no central authority. The two most prominent public blockchains are Ethereum and Bitcoin.

54. What Is Private Blockchain? Give examples.

A private blockchain is just that—private. They are controlled by a centralized authority. Because it is not open to all, it is perfect for banks and other concentrated institutions. Consider Hyperledger.

  • Do not miss adding these kinds of blockchain developer interview questions to your revision list when preparing to crack your blockchain intern at the first trial. 
  • Do you know the skills required to become a blockchain developer? Here is the guide on Blockchain Developer Skills

55. What do you think will happen with blockchain technology?

The future of blockchain is promising. It is now in the development stage, with breakthroughs in both technology and adoption. The fact that it is used in virtually every business speaks loudly about its potential. 

As more and more investors show interest in blockchain technology, we will observe a significant impact on the blockchain, both industrially and in daily life.

56. How can you stop spending money twice?

Double spending is avoided by the blockchain thanks to the consensus method. Before adding the transaction to the block, the consensus algorithm confirms its validity. It is therefore verified by a number of nodes, enabling double-spending.

57. Blockchain: Is it a trustworthy ledger?

This is among the most commonly asked blockchain interview questions.

Blockchain is an irreproachable ledger, yes. The blockchain database cannot be tampered with, claims the inventor.

58. Why is a trapdoor function necessary for blockchain development, and what does it do?

A function known as a trapdoor function is one that is simple to compute in one direction but challenging to compute in the opposite direction absent particular knowledge. Trapdoor functions are frequently used in blockchain development to symbolize the concepts of addresses and private keys because they are crucial for public key encryption. 

Do not miss adding these kinds of blockchain developer interview questions to your revision list when preparing to crack your blockchain intern at the first trial. 

59. How do verifiers determine the validity of a block?

The network's entire nodes do block verification. Every node that receives a new block performs a series of checks. The two most crucial checks are the ones that determine if a block offers enough work to be added to the chain and whether all transactions are genuine (each transaction must be valid).

60. Double Spending: What Is It?

This is among the most commonly asked blockchain interview questions.

The act of spending the same digital currency twice without network security recognizing it is known as double-spending. The financial institution takes extra precautions to ensure that they prevent double spending at all costs because it is one of the major issues in the market. The basic method is to trick the network into believing that the initial sum is never spent.

61. How does the Blockchain approach identify blocks?

 In this online ledger, each block simply comprises a hash reference that serves as a connection to the block that came before it, transactional information, and actually a time stamp.

Conclusion

Blockchain technology will drive the digital revolution in the next years. You can pass blockchain interviews if you have the required technical know-how and sound logical thinking skills. 

I sincerely hope that these Blockchain developer interview questions will be helpful to you.

Do you have a query for us? If you would like a response, kindly leave a comment, and we will do so as soon as possible.

Enroll in the Online Blockchain Developer Training if you want to learn about blockchain technology and pursue a career in the field. You'll have access to support around the clock as you progress through the course.


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    JanBask Training

    A dynamic, highly professional, and a global online training course provider committed to propelling the next generation of technology learners with a whole new way of training experience.


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Comments

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    Maximiliano Jackson

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