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Top 20 Blockchain Developer Interview Questions with Answers in 2023

Hello guys, if you are preparing for Blockchain developer interviews or looking for any job in the Blockchain technology field but wondering how to prepare then you have come to the right place. Earlier, I have shared best Blockchain courses and Blockchain websites and in this article, I am going to share 20 common Blockchain interview questions with answers. These Blockchain questions not only covers key Blockchain concepts like nodes, hashing, transaction, and different types of Blockchain network like Ethereum, HyperLedger Fabric, Smart Contracts etc but also provide their to the point answers so that you can revise them quickly. If you have worked as Blockchain developer then you can easily answer these questions but if you cannot then you can also check these free Blockchain courses to learn and revise important Blockchain concepts.
Blockchain is becoming more and more popular as days go by. Many people are associating themselves with it and therefore an interview in this area tends to be more serious and straightforward.

This means that the hiring team has to make sure that they are really hiring the right person who will be able to be useful in the organization in the best way possible.

The interview panel will know you are the person they are looking for if you answer the questions they will ask correctly. You are shortly going to know the kind of questions commonly asked because I have listed below the top 20 Blockchain interview questions with answers.

20 Blockchain Interview Questions with Answers in 2023

Without any further ado, here is a list of common Blockchain questions from interviews. You can use this list to quickly revise both important Blockchain interview questions as well essential Blockchain concepts. These questions are useful for both beginners and experienced programmers who have done Blockchain development work.

1. What are the different types of Blockchain?
Answer: The blockchain is classified into four types as follows:

  • Public Blockchains
  • Private Blockchains
  • Consortium Blockchains
  • Hybrid Blockchains.

2. What are the properties of Blockchain?
Answer: There are four key features of blockchain which are as follows:

  • Decentralized Systems
  • Distributed ledger
  • Safer & Secure Ecosystem
  • Minting

3. What are some of the popular Blockchain Platforms for Blockchain Applications?
Answer: The following are the widely-used platforms for blockchain-based applications

  • IBM Blockchain
  • EOS
  • OpenLedger
  • Corda
  • Ripple
  • Ethereum
  • IOTA
  • Quorum
  • OpenChain
  • Hyperledger Sawtooth

4. What Are the Components of a Blockchain Ecosystem?
Answer: The blockchain ecosystem has four main components. They are as follows.

  • Node application
  • Shared ledger
  • Consensus algorithm
  • Virtual Machine

5. What are the parts of EVM memory?
Answer: The memory of an EVM is divided into three types:

  • Storage values are stored permanently on the Blockchain network
  • It is extremely expensive


  • Memory is a temporary modifiable storage
  • It can be accessed only during contract execution. Once the execution is finished, its data is lost


  • A stack is a temporary and non-modifiable storage.
  • Here, when the execution completes, the content is lost.

6. What are the major elements of a block?
Answer: A block has the following three elements:

  • A hash pointer to the previous block
  • Timestamp
  • List of transactions
Here is a nice diagram explaining how Blockchain works:

Blockchain interview questions with answers

7. Which type of records can be kept in the blockchain?

  • Transaction processing
  • Identity management
  • Events related to organizations
  • Management activities
  • Documentation
  • Records of medical transactions

8. What is the consensus algorithm?
Answer: A consensus algorithm is a method through which all the peers of the blockchain network reach a standard agreement of the present state of a distributed ledger. It achieves high reliability and establishes trust between unknown peers in the distributed computing environment.

what is blockchain

9. What are the types of consensus algorithms?
Answer: The following are the most popular consensus algorithms:

  • Proof-of-Work (PoW)
  • Proof-of-Capacity (PoC)
  • Proof-of-Activity (PoA)
  • Delegated Proof-of-Stake (DPoS)
  • Proof-of-Stake (PoS)
  • Proof-of-Authority
  • Proof-of-Burn
  • Unique Node Lists
  • Proof-of-Weight
  • Proof-of-Elapsed Time
  • Byzantine Fault Tolerance

10. What are the benefits of using blockchain technology?
Answer: The key benefits of using blockchain technology are as follows:

  • Enhanced security
  • Improved traceability
  • Cost-saving
  • User pseudonymity
  • Immutability
  • Transparency of transactions
  • Automatic reconciliation of accounts
  • Fraud control
  • No payment for intermediaries services

11. What type of records can be kept in a Blockchain? Is there any restriction on the same?
Answer: There is no restriction on keeping records of any type in the Blockchain approach. Industries are using Blockchain for securing all types of records.

Top 20 Blockchain Interview Questions With Answers

12. What are ledgers? What are the common types of ledgers that are considered by users in blockchain?
Answer: A ledger is a file that is growing continuously. It stores the permanent record of all the transactions taking place between the two parties on the blockchain network. The common types of ledgers considered by the users in the Blockchain are as follows:

  • Centralized Ledgers
  • Decentralized Ledgers
  • Distributed Ledgers

13. What does BIP stand for?
Answer: BIP stands for Bitcoin Improvement Proposal.

14. What is double-spending?
Answer: Double-spending is considered to be a potential flaw in the digital cash scheme because the same digital tokens are used multiple times. The tokens generally consist of digital files that can be easily cloned.

Blockchain questions for interviews

15. What is a blind signature?
Answer: A blind signature is a form of digital signature in cryptography where the content of the message is blinded before it is signed or considered.

16. What are the key principles in a blockchain that help in eliminating security threats?

  • Continuity planning
  • Auditing
  • Securing testing and similar approaches
  • Database security
  • Securing applications
  • Digital workforce training

17. What is the difference between Proof-of-Stake and Proof-of-Work?

  • Proof-of-Work is the original Consensus algorithm in the blockchain. It is used for confirming transactions and producing new blocks to the chain. In this miners compete with each other to complete the transactions on the network and get rewarded.
  • Proof-of-Stake makes the consensus mechanism completely virtual. In this, a set of nodes decide to stake their cryptocurrencies of the transaction validation.

18. What is a Coinbase transaction?
Answer: A Coinbase transaction is a unique type of bitcoin transaction that is created by miners. It is the first transaction in the new block. The miners use it to collect the block reward of their work. Any transaction fees collected by the miners are also sent in this transaction.

19. What is Secret Sharing?
Answer: Secret Sharing is one of the primary methods used for providing data security in blockchain. This approach segregates personal or secret information into various units and sends them to the users on the network. The original information is shared for participants to whom the share of the secret is allocated.

20. What is a trapdoor function in blockchain development?
Answer: A trapdoor function is a one-way function, i.e., easy to compute in one direction but hard to compute in the opposite direction unless you have the special information. These functions are essential for public-key encryption and are most widely used in blockchain development to represent the ideas of addresses and private keys.

That's all about common Blockchain interview questions for beginners and 2 to 3 years experienced professionals. After going through the above-mentioned questions, you are now one step ahead of the other candidates because you already have a clue of what will be asked in the interview room. What you have to do now is to make sure you remember the answers and answer them correctly when asked. It will be easy for sure. 

Try your level best to trust yourself.

Other Blockchain Articles and Tutorials you may like:

All the best for your Blockchain Developer Interview !! If you become a Blockchain Developer or Blockchain architect, don't forget to share your success with us. We would love to hear your story as it will motivate us as and others. 

P. S. - If you are new to Blockchain world and want to learn Blockchain in depth then you can also checkout this list of best Blockchain online courses. It contains best Blockchain courses form Udemy , one of the best online portals to learn Blockchain in 2023. 

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