Blockchain Developer Test

About the test:

The Blockchain Developer Online Test uses scenario-based multiple choice questions to evaluate candidates on their technical knowledge and practical skills related to blockchain development, covering topics such as blockchain architecture, consensus algorithms, smart contracts, cryptocurrency, token economics, decentralized applications (dApps), and blockchain security. The test aims to determine candidates' ability to build innovative blockchain solutions that solve real-world problems and meet business needs.

Covered skills:

Participant Roles
Chain code
Ethereum Mining
EVM
Ethereum- Smart contract

Validation
Hyperledger Composer
Ethereum- geth
Ethereum Application
Blockchain – Mining

See all covered skills

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9 reasons why

Adaface Blockchain Developer Test is the most accurate way to shortlist Blockchain Developers

Reason #1

Tests for on-the-job skills

The Blockchain Developer Test helps recruiters and hiring managers identify qualified candidates from a pool of resumes, and helps in taking objective hiring decisions. It reduces the administrative overhead of interviewing too many candidates and saves time by filtering out unqualified candidates.

The Adaface Blockchain Developer Online Test screens candidates for the typical skills recruiters look for Sharepoint Administrator/Specialist roles:

Experience working with large codebases
Experience with open-source projects
Proficiency in C++, Java, JavaScript
Knowledge of common algorithms and data structures
Familiarity with cryptography and P2P networks
Knowledge of concurrency and writing efficient and safe multithreaded code

The insights generated from this assessment can be used by recruiters and hiring managers to identify the best candidates for Blockchain Developer roles. Anti-cheating features enable you to be comfortable with conducting assessments online. The Blockchain Developer Online Test is ideal for helping recruiters identify which candidates have the skills to do well on the job.

Reason #2

No trick questions

Traditional assessment tools use trick questions and puzzles for the screening, which creates a lot of frustration among candidates about having to go through irrelevant screening assessments.

The main reason we started Adaface is that traditional pre-employment assessment platforms are not a fair way for companies to evaluate candidates. At Adaface, our mission is to help companies find great candidates by assessing on-the-job skills required for a role.

Why we started Adaface ->

Reason #3

Non-googleable questions

We have a very high focus on the quality of questions that test for on-the-job skills. Every question is non-googleable and we have a very high bar for the level of subject matter experts we onboard to create these questions. We have crawlers to check if any of the questions are leaked online. If/ when a question gets leaked, we get an alert. We change the question for you & let you know.

These are just a small sample from our library of 10,000+ questions. The actual questions on this Blockchain Developer Test will be non-googleable.

🧐 Question
Medium 51% Attacks	Solve
A 51% attack is perhaps the most discussed threat to any public Blockchain asset. A 51% attack happens when a certain miner or mining pool, that owns more than 50% of all the network’s hashing power, acts maliciously to disturb the network’s operation. For example: Two Bitcoin Cash mining pools, carried out a 51% attack on the Bitcoin Cash blockchain in order to stop an unknown miner from taking coins that they weren’t supposed to have access to, while the network forked. Which of the following CAN be done by a miner employing a 51% attack? A: Double spend their coins B: Reverse confirmed transactions C: Steal funds from a certain address D: Prevent transactions from being confirmed E: Create false transactions that never happened
Medium Evidence	Solve
Breed Chasing, solo engineer is planning to create new cryptocurrency, NEWCRAIGLIST and build a blockchain that facilitates buying and selling second-hand items with NEWCRAIGLIST from each other. Breed expects the platform to be used for international transactions and devised the following process: - Before a transaction is considered complete, the purchaser must put the funds in an escrow service - The sender must enter the courier tracking number into that same escrow Palmart, toy store giant in US is asked by lawmakers to provide evidence that proves the store’s toys are not produced through child labour. Palmart’s toys are transferred between 7 parties between creation and placement at the store. Palmart is considering using blockchain to solve this problem. Discretion in the reading and writing of transactions is highly important to the store chain to protect its proprietary interests. Review the following possible solutions and pick the best approach that solves Palmart’s problem: Option A: Use a public blockchain that supports assets. Then create a new toy asset for each item created. When the toy is transferred to the next party, mandate that the associated blockchain asset to be transferred to the next party's blockchain account with required metadata. Lawmakers can now view transactions and transfers at any time. Option B: Use a permissioned blockchain. Require that every party involved in the process to host a node on the Palmart's network. Create a new toy asset for each item created. When the toy is transferred to the next party in the process, have the previous party use a web portal to initialize a chain code Smart Contract to transfer control of the asset. When the next party receives the asset have them use a web portal to initialize a chain code Smart Contracts to acknowledge receipt of the asset. Provide read-only permissions to the lawmakers so they can receive the evidence they are looking for.

	🧐 Question	🔧 Skill
	Medium 51% Attacks	3 mins Blockchain	Solve
A 51% attack is perhaps the most discussed threat to any public Blockchain asset. A 51% attack happens when a certain miner or mining pool, that owns more than 50% of all the network’s hashing power, acts maliciously to disturb the network’s operation. For example: Two Bitcoin Cash mining pools, carried out a 51% attack on the Bitcoin Cash blockchain in order to stop an unknown miner from taking coins that they weren’t supposed to have access to, while the network forked. Which of the following CAN be done by a miner employing a 51% attack? A: Double spend their coins B: Reverse confirmed transactions C: Steal funds from a certain address D: Prevent transactions from being confirmed E: Create false transactions that never happened
	Medium Evidence	3 mins Blockchain	Solve
Breed Chasing, solo engineer is planning to create new cryptocurrency, NEWCRAIGLIST and build a blockchain that facilitates buying and selling second-hand items with NEWCRAIGLIST from each other. Breed expects the platform to be used for international transactions and devised the following process: - Before a transaction is considered complete, the purchaser must put the funds in an escrow service - The sender must enter the courier tracking number into that same escrow Palmart, toy store giant in US is asked by lawmakers to provide evidence that proves the store’s toys are not produced through child labour. Palmart’s toys are transferred between 7 parties between creation and placement at the store. Palmart is considering using blockchain to solve this problem. Discretion in the reading and writing of transactions is highly important to the store chain to protect its proprietary interests. Review the following possible solutions and pick the best approach that solves Palmart’s problem: Option A: Use a public blockchain that supports assets. Then create a new toy asset for each item created. When the toy is transferred to the next party, mandate that the associated blockchain asset to be transferred to the next party's blockchain account with required metadata. Lawmakers can now view transactions and transfers at any time. Option B: Use a permissioned blockchain. Require that every party involved in the process to host a node on the Palmart's network. Create a new toy asset for each item created. When the toy is transferred to the next party in the process, have the previous party use a web portal to initialize a chain code Smart Contract to transfer control of the asset. When the next party receives the asset have them use a web portal to initialize a chain code Smart Contracts to acknowledge receipt of the asset. Provide read-only permissions to the lawmakers so they can receive the evidence they are looking for.

	🧐 Question	🔧 Skill	💪 Difficulty	⌛ Time
	51% Attacks	Blockchain	Medium	3 mins	Solve
A 51% attack is perhaps the most discussed threat to any public Blockchain asset. A 51% attack happens when a certain miner or mining pool, that owns more than 50% of all the network’s hashing power, acts maliciously to disturb the network’s operation. For example: Two Bitcoin Cash mining pools, carried out a 51% attack on the Bitcoin Cash blockchain in order to stop an unknown miner from taking coins that they weren’t supposed to have access to, while the network forked. Which of the following CAN be done by a miner employing a 51% attack? A: Double spend their coins B: Reverse confirmed transactions C: Steal funds from a certain address D: Prevent transactions from being confirmed E: Create false transactions that never happened
	Evidence	Blockchain	Medium	3 mins	Solve
Breed Chasing, solo engineer is planning to create new cryptocurrency, NEWCRAIGLIST and build a blockchain that facilitates buying and selling second-hand items with NEWCRAIGLIST from each other. Breed expects the platform to be used for international transactions and devised the following process: - Before a transaction is considered complete, the purchaser must put the funds in an escrow service - The sender must enter the courier tracking number into that same escrow Palmart, toy store giant in US is asked by lawmakers to provide evidence that proves the store’s toys are not produced through child labour. Palmart’s toys are transferred between 7 parties between creation and placement at the store. Palmart is considering using blockchain to solve this problem. Discretion in the reading and writing of transactions is highly important to the store chain to protect its proprietary interests. Review the following possible solutions and pick the best approach that solves Palmart’s problem: Option A: Use a public blockchain that supports assets. Then create a new toy asset for each item created. When the toy is transferred to the next party, mandate that the associated blockchain asset to be transferred to the next party's blockchain account with required metadata. Lawmakers can now view transactions and transfers at any time. Option B: Use a permissioned blockchain. Require that every party involved in the process to host a node on the Palmart's network. Create a new toy asset for each item created. When the toy is transferred to the next party in the process, have the previous party use a web portal to initialize a chain code Smart Contract to transfer control of the asset. When the next party receives the asset have them use a web portal to initialize a chain code Smart Contracts to acknowledge receipt of the asset. Provide read-only permissions to the lawmakers so they can receive the evidence they are looking for.

Reason #4

1200+ customers in 75 countries

With Adaface, we were able to optimise our initial screening process by upwards of 75%, freeing up precious time for both hiring managers and our talent acquisition team alike!

Brandon Lee, Head of People, Love, Bonito

Reason #5

Designed for elimination, not selection

The most important thing while implementing the pre-employment Blockchain Developer Test in your hiring process is that it is an elimination tool, not a selection tool. In other words: you want to use the test to eliminate the candidates who do poorly on the test, not to select the candidates who come out at the top. While they are super valuable, pre-employment tests do not paint the entire picture of a candidate’s abilities, knowledge, and motivations. Multiple easy questions are more predictive of a candidate's ability than fewer hard questions. Harder questions are often "trick" based questions, which do not provide any meaningful signal about the candidate's skillset.

Reason #6

1 click candidate invites

Email invites: You can send candidates an email invite to the Blockchain Developer Test from your dashboard by entering their email address.

Public link: You can create a public link for each test that you can share with candidates.

API or integrations: You can invite candidates directly from your ATS by using our pre-built integrations with popular ATS systems or building a custom integration with your in-house ATS.

Reason #7

Detailed scorecards & benchmarks

Reason #8

High completion rate

Adaface tests are conversational, low-stress, and take just 25-40 mins to complete.

This is why Adaface has the highest test-completion rate (86%), which is more than 2x better than traditional assessments.

Reason #9

Advanced Proctoring

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About Blockchain Developer Roles

Blockchain is a shared, immutable ledger that facilitates the process of recording transactions and tracking assets in a business network.

A blockchain developer is someone who creates and optimises blockchain protocols, designs the architecture of blockchain systems, and creates smart contracts and web apps that use blockchain technology.

Typical Blockchain Developer responsibilities include:

Researching, designing, developing, and testing blockchain technologies
Brainstorming and helping evaluate applications for new tools and technologies as they continually evolve
Maintaining and extending current client- and server-side applications responsible for integration and business logic
Documenting new solutions as well as maintaining that of existing ones

What roles can I use the Blockchain Developer Test for?

Blockchain Developer
Blockchain Engineer

What topics are covered in the Blockchain Developer Test?

Decentralized Distributed Database

Bitcoin Blockchain

Ethereum Blockchain

Types Of Blockchains

Records

Decentralized Systems

Distributed Ledger

Minting

Encryption

Blocks

Block Identifiers

Merkle Trees

Incorruptible Ledger

Proof-Of-Work

Proof-Of-Stake

Double Spending

Cryptographic Algorithms

Blind Signature

Secret Sharing

Off-Chain Transactions

Executive Accounting

51% Attack

Security Policy

Consensus Algorithms

RSA Algorithm

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The hiring managers felt that through the technical questions that they asked during the panel interviews, they were able to tell which candidates had better scores, and differentiated with those who did not score as well. They are highly satisfied with the quality of candidates shortlisted with the Adaface screening.

85%

reduction in screening time

View Full Case Study

FAQs

Can I combine multiple skills into one custom assessment?

Yes, absolutely. Custom assessments are set up based on your job description, and will include questions on all must-have skills you specify.

Do you have any anti-cheating or proctoring features in place?

We have the following anti-cheating features in place:

Non-googleable questions
IP proctoring
Web proctoring
Webcam proctoring
Plagiarism detection
Secure browser

Read more about the proctoring features.

How do I interpret test scores?

The primary thing to keep in mind is that an assessment is an elimination tool, not a selection tool. A skills assessment is optimized to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best candidate for the role. So the ideal way to use an assessment is to decide a threshold score (typically 55%, we help you benchmark) and invite all candidates who score above the threshold for the next rounds of interview.

What experience level can I use this test for?

Each Adaface assessment is customized to your job description/ ideal candidate persona (our subject matter experts will pick the right questions for your assessment from our library of 10000+ questions). This assessment can be customized for any experience level.

Does every candidate get the same questions?

Yes, it makes it much easier for you to compare candidates. Options for MCQ questions and the order of questions are randomized. We have anti-cheating/ proctoring features in place. In our enterprise plan, we also have the option to create multiple versions of the same assessment with questions of similar difficulty levels.