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About the test:

The Backend Engineer Online Test uses scenario-based MCQs to evaluate candidates on their knowledge of backend development, which involves designing and implementing server-side logic, databases, and APIs to support web and mobile applications. The test assesses candidates' proficiency in designing scalable and robust architectures, writing efficient code in languages such as Java, Python, or Ruby, building and integrating with databases, implementing RESTful APIs, and debugging and optimizing server-side code.

Covered skills:

  • REST APIs
  • Coding
  • Web Fundamentals
  • Databases
See all covered skills

9 reasons why
9 reasons why

Adaface Backend Engineer Online Test is the most accurate way to shortlist Backend Engineers



Reason #1

Tests for on-the-job skills

The Back-End Engineer 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 Back-End Engineer Online Test screens candidates for the typical skills recruiters look for Back-End Engineer roles:

  • Knowledge of PHP, Python, Ruby, Java,.NET, JavaScript, and other programming languages
  • Extensive understanding of HTML and CSS
  • Knowledge of web server technologies such as NGINX, Apache, and J2EE
  • In-depth knowledge of OOP and software design concepts
  • Understanding of database management systems and NoSQL databases
  • Knowledge of Linux/Unix
  • Understanding of scripting languages such as Perl, Shell scripting, and others
  • Working knowledge of SASS and LASS

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

Reason #2

No trick questions

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 Backend Engineer Test will be non-googleable.

🧐 Question

Medium

Broker Replication
System Design
Solve
You are working on a large-scale, distributed, and fault-tolerant message processing system designed to handle high throughput and low latency requirements. The system is based on the publish-subscribe pattern and uses multiple brokers to distribute messages across various topics and partitions. In this architecture, both publishers and subscribers are considered clients. The brokers are responsible for replicating messages among themselves to ensure fault tolerance and data durability.
 image
A client reports successfully publishing a message on a specific topic. However, one of the subscribers has not received the message. To investigate the issue, you have gathered detailed logs and system design data, as shown below:
 image
Based on the information provided, which of the following is the most likely reason for the issue?

A: The message was not published on the topic
B: Client C is not subscribed to the correct topic
C: There is a replication lag between brokers B1 and B2
D: Client C is consuming from the wrong broker
E: The message processing system failed to acknowledge the message

Medium

Load Balancer Latency
Debugging
Solve
A backend service is experiencing intermittent latency spikes while processing incoming requests. The service is deployed in a multi-node environment with a load balancer in front. You suspect that the issue might be related to resource contention. You collect the following performance metrics from the affected nodes during a spike:
 image
Which of the following is the most probable cause of the latency spikes?
A: High memory usage on the affected nodes.
B: Disk I/O bottlenecks on the affected nodes.
C: Insufficient CPU resources on the affected nodes.
D: Uneven distribution of incoming requests by the load balancer.
E: Network latency between the load balancer and the backend nodes.

Medium

Decryptor
Strings
Solve
What does the following pseudo code print?
 image

Hard

Fibonacci codes
Time Complexity
Pseudo Code
Solve
Here are three pseudocodes for calculating the Nth Fibonacci number. Which of the following statements about these codes are true?
 image
A: Time complexity/efficiency of CODE 1, CODE 2, CODE 3 is the same.
B: CODE 2 is more space-efficient than CODE 3.
C: CODE 3 is more space-efficient than CODE 2.
D: CODE 2 is more time-efficient than CODE 1.
E: CODE 3 is more time-efficient than CODE 1.

Hard

Palindrome Test cases
Strings
Solve
Go through the following faulty palindrome detection pseudocode and test cases. For which of the test cases would the code return true?
 image
Testcases
A: a
B: aba
C: aaa
D: aac

Medium

Rewards Activities Order
Database Connection
Solve
A new popular app tracks the activities performed by its users and grants them rewards based on each individual's total activities performed in a year. This data is maintained in a database table (activitesinfo), with the following columns: userid, totalactivities, reward. This year, due to fundraising activity, the company has decided to further reward its users by enhancing the reward as per the following formula: If reward < = 4000, increase it by 2%, If 4000 < reward <= 8000, increase it by 4%, If reward > 8000, increase it by 6%.
The tech team has written three different scripts to calculate increment for each slab, each script is to run as a separate transaction. Here are the three scripts:
Script 1:
For users with reward <= 4000, set reward = reward * 1.02

Script 2:
For users with reward > 4000 and reward <= 8000, set reward = reward * 1.04

Script 3:
For users with reward > 8000, set reward = reward * 1.06
Each script is to be executed separately. Which of the following options will update the rewards as expected:
A: Execute Script 1 followed by Script 2 followed by Script 3
B: Execute Script 2 followed by Script 3; Script 1 running concurrently throughout
C: Execute Script 3 followed by Script 2; Script 1 running concurrently throughout
D: Execute Script 3 followed by Script 2 followed by Script 1
E: Execute Script 2 followed by Script 3 followed by Script 1

Easy

Registration Queue
Logic
Queues
Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount.
For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition.
⚠️⚠️⚠️ Note:
- The first line of the input is the length of the array. The second line contains all the elements of the array.
- The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function.
- You need to "print" the final result (not return it) to pass the test cases.

For the example discussed above, the input will be:
5
20 70 -40 30 -10

Your code needs to print the following to the standard output:
20 70 30 -40 -10

Medium

Visitors Count
Strings
Logic
Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. 
Example:

Input:
WWMMWWCCC

Expected Output: 
4W3C2M

Explanation: 
‘W’ has the highest count, then ‘C’, then ‘M’. 
⚠️⚠️⚠️ Note:
- The input is already parsed and passed to a function.
- You need to "print" the final result (not return it) to pass the test cases.
- If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’.
- If any of them have the same count, the output should follow this order - M, W, C.
🧐 Question🔧 Skill

Medium

Broker Replication
System Design
3 mins
Backend
Solve

Medium

Load Balancer Latency
Debugging
3 mins
Backend
Solve

Medium

Decryptor
Strings
2 mins
Technical Aptitude
Solve

Hard

Fibonacci codes
Time Complexity
Pseudo Code
2 mins
Technical Aptitude
Solve

Hard

Palindrome Test cases
Strings
2 mins
Technical Aptitude
Solve

Medium

Rewards Activities Order
Database Connection
3 mins
Technical Aptitude
Solve

Easy

Registration Queue
Logic
Queues
30 mins
Coding
Solve

Medium

Visitors Count
Strings
Logic
30 mins
Coding
Solve
🧐 Question🔧 Skill💪 Difficulty⌛ Time
Broker Replication
System Design
Backend
Medium3 mins
Solve
Load Balancer Latency
Debugging
Backend
Medium3 mins
Solve
Decryptor
Strings
Technical Aptitude
Medium2 mins
Solve
Fibonacci codes
Time Complexity
Pseudo Code
Technical Aptitude
Hard2 mins
Solve
Palindrome Test cases
Strings
Technical Aptitude
Hard2 mins
Solve
Rewards Activities Order
Database Connection
Technical Aptitude
Medium3 mins
Solve
Registration Queue
Logic
Queues
Coding
Easy30 minsSolve
Visitors Count
Strings
Logic
Coding
Medium30 minsSolve
Reason #4

1200+ customers in 75 countries

customers in 75 countries
Brandon

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 Backend Engineer 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 Backend Engineer 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.

invite candidates
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.

test completion rate
Reason #9

Advanced Proctoring


About Back-End Engineer Roles

The back-end refers to the components of a computer application or program's code that allow it to function, but the user cannot view it. Most data and operational syntax are kept and accessed in the computer system's back end.

A back-end engineer is often in charge of creating the structure of a software programme. They'll mostly be responsible for building business logic, server scripts, and application programming interfaces (APIs) that front-end developers and UX designers will use.

Typical Back-End Engineer responsibilities include:

  • Create software that is fast, responsive, and scalable in C++, Ruby, Scala, and Java
  • Work with product and design teams to understand end-user needs
  • Create and implement service and system architecture for customer projects
  • Collaborate with cross-functional teams to generate new ideas
  • Assist in maintaining code quality by completing code reviews, unit tests, and automation
  • Create and deploy data storage systems
  • Set up back-end usability to ensure effective front-end integration
  • Establish best practices for back-end software engineering

What roles can I use the Backend Engineer Test for?

  • Backend Engineer
  • Full Stack Developer
  • Software Engineer
  • API Developer
  • Software Architect

What topics are covered in the Backend Engineer Online Test?

CAP Theorem

REpresentational State Transfer

REST
NoSQL Databases
SQL Injection
Continuous Integration
MongoDB
Functional Testing
Acceptance Testing
Go Program

Interoperability, Reusability, Loose Coupling

Web Services
Containerization
Microservices Architecture
Performance Testing

High Availability

HA

Atomicity, Consistency, Isolation, Durable

ACID Property
Sticky Session Load Balancing
Session Affinity

Don't Repeat Yourself

DRY Principles

Duplication is Evil

DIE Principles
Clustered and Non-clustered Index
Continuous Integration
Continuous Delivery
Continuous Deployment
Monolithic Architecture

Service-Oriented Architecture

SOA Architecture
API Gateway Pattern
SSL/TLS
B-Trees Index
BASE Property
Distributed Transaction
Spike Testing
Twelve-Factor App Principles
RESTful API Design
Singapore government logo

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

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.

I'm a candidate. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment. However, you can use our sample questions for practice.

What is the cost of using this test?

You can check out our pricing plans.

Can I get a free trial?

Yes, you can sign up for free and preview this test.

I just moved to a paid plan. How can I request a custom assessment?

Here is a quick guide on how to request a custom assessment on Adaface.

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