What is a common cause of an N+1 query problem in an application using an ORM?
Anonymous Quiz
13%
Using too many indexes on one table
73%
One query per parent's children instead of a single join
13%
Using JOINs instead of subqueries
3%
Caching query results too aggressively
Why might a system use a Content Delivery Network (CDN)?
Anonymous Quiz
2%
To compress source code
94%
To serve static content from servers closer to the user
4%
To manage user authentication
0%
To handle database transactions
What does horizontal scaling mean?
Anonymous Quiz
30%
Upgrading a single server's CPU and RAM
65%
Adding more servers to share the load
5%
Reducing the number of database tables
0%
Compressing files to save space
Why is idempotent design particularly important with at-least-once delivery message queues?
Anonymous Quiz
35%
Because at-least-once queues never actually redeliver messages
55%
The queue may deliver the same message more than once
10%
Because it makes messages arrive faster
0%
It's not relevant to at-least-once delivery
What does the spread operator do when used on an object, like {...obj}?
Anonymous Quiz
9%
Deep clones the object recursively
80%
Creates a shallow copy, copying only the top-level properties
6%
Mutates the original object in place
6%
Only works on arrays, not objects
What is a common reason to introduce a circuit breaker pattern between services?
Anonymous Quiz
0%
To permanently block a failing dependency forever
83%
Stops calling a failing service so it has time to recover
0%
To increase the number of retries indefinitely
17%
To encrypt traffic between services
How does @staticmethod differ from @classmethod in Python?
Anonymous Quiz
45%
A staticmethod receives the class as its first argument, a classmethod doesn't
37%
staticmethod gets neither; classmethod automatically gets the class
13%
They behave identically
5%
staticmethod can only be used with private methods
What is the result of typeof null in JavaScript?
Anonymous Quiz
23%
"null"
51%
"undefined"
21%
"object"
4%
"boolean"
❤1
Which protocol is primarily responsible for translating domain names such as example.com into IP addresses?
Anonymous Quiz
4%
FTP
88%
DNS
4%
SSH
4%
SMTP
❤1
Which practice most directly reduces the risk of SQL injection in an application?
Anonymous Quiz
68%
Parameterized queries
0%
Longer variable names
26%
More CSS validation
5%
Disabling browser cookies
Which technique is commonly used to distribute incoming requests across multiple servers?
Anonymous Quiz
79%
Load balancing
5%
Data encryption
16%
Code compilation
0%
File compression
Which HTML element is used to create a hyperlink?
Anonymous Quiz
3%
<img>
12%
<link>
44%
<a>
41%
<href>