Hiring guide for Dao+++ Engineers

Dao+++ Developer Hiring Guide

The Dao+++ computer software programming language is a high-level, statically-typed, and object-oriented language. It was developed by Limin Fu in 2009, with the aim of providing a simple yet powerful tool for software development. The language is known for its unique features such as routine-based concurrent programming and optional garbage collection. According to its official documentation, Dao+++ supports multiple programming paradigms including procedural, object-oriented, and functional programming. Its design philosophy emphasizes simplicity, efficiency, and flexibility, making it a versatile choice for various types of software projects.

Ask the right questions secure the right Dao+++ talent among an increasingly shrinking pool of talent.

First 20 minutes

General Dao+++ app knowledge and experience

The first 20 minutes of the interview should seek to understand the candidate's general background in Dao+++ application development, including their experience with various programming languages, databases, and their approach to designing scalable and maintainable systems.

What are the basic data types in Dao++?
The basic data types in Dao++ are int, float, double, complex, string, enum, array, list, map, and class.
How would you declare a variable in Dao++?
In Dao++, you declare a variable using the 'var' keyword followed by the variable name and its value. For example, 'var x = 10'.
What is the purpose of the 'invar' keyword in Dao++?
The 'invar' keyword in Dao++ is used to declare a variable that cannot be modified. It is essentially a constant.
How would you implement a loop in Dao++?
In Dao++, you can implement a loop using the 'for' keyword. For example, 'for(i=0; i<10; i++) { //code }'.
What is the difference between '==' and '===' in Dao++?
'==' is used for equality comparison, while '===' is used for identity comparison. '==' checks if the values are equal, while '===' checks if the values and types are equal.
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What you’re looking for early on

Have they demonstrated a deep understanding of Dao+++'s syntax and semantics?
Can the candidate solve complex problems using Dao+++?
Does the candidate understand and apply best practices in Dao+++ coding?
Is the candidate comfortable with advanced Dao+++ features?

Next 20 minutes

Specific Dao+++ development questions

The next 20 minutes of the interview should focus on the candidate's expertise with specific backend frameworks, their understanding of RESTful APIs, and their experience in handling data storage and retrieval efficiently.

How would you handle exceptions in Dao++?
In Dao++, exceptions are handled using the 'try-catch' block. The 'try' block contains the code that may throw an exception, and the 'catch' block contains the code to handle the exception.
What are the different types of operators in Dao++?
Dao++ has arithmetic operators, comparison operators, logical operators, bitwise operators, and assignment operators.
How would you define a function in Dao++?
In Dao++, a function is defined using the 'def' keyword followed by the function name, parameters, and body. For example, 'def add(x, y) { return x + y; }'.
What is the difference between a list and an array in Dao++?
In Dao++, a list is a dynamic array-like container that can hold any type of data, while an array is a static container that can only hold data of a specific type.
How would you create a class in Dao++?
In Dao++, a class is created using the 'class' keyword followed by the class name and body. For example, 'class MyClass { var x; def method() { //code } }'.
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The ideal back-end app developer

What you’re looking to see on the Dao+++ engineer at this point.

At this point, a skilled Dao+++ engineer should demonstrate strong problem-solving abilities, proficiency in Dao+++ programming language, and knowledge of software development methodologies. Red flags include lack of hands-on experience, inability to articulate complex concepts, or unfamiliarity with standard coding practices.

Digging deeper

Code questions

These will help you see the candidate's real-world development capabilities with Dao+++.

What does the following basic DAO code do?
public interface UserDao { List getAllUsers(); User getUser(int id); void updateUser(User user); void deleteUser(User user); }
This is an interface for a Data Access Object (DAO) for User objects. It defines methods for getting all users, getting a specific user by id, updating a user, and deleting a user.
What will be the output of the following DAO syntax?
public class UserDaoImpl implements UserDao { private List users; public UserDaoImpl() { users = new ArrayList(); } public List getAllUsers() { return users; } } UserDao userDao = new UserDaoImpl(); System.out.println(userDao.getAllUsers());
This will print out an empty list because when the UserDaoImpl is instantiated, it creates an empty ArrayList of users. Since we haven't added any users to the list, it will print out as empty.
What does the following collection manipulation method do in DAO?
public void updateUser(User user) { users.get(user.getId()).setName(user.getName()); System.out.println('User: Id ' + user.getId() + ', updated in the database'); }
This method updates the name of a User object in the users list. It fetches the user by id from the list and sets its name to the new name. Then it prints out a message saying that the user was updated in the database.
What does the following concurrency related code do in DAO?
public synchronized void updateUser(User user) { users.get(user.getId()).setName(user.getName()); System.out.println('User: Id ' + user.getId() + ', updated in the database'); }
The 'synchronized' keyword in this method ensures that only one thread can execute this method at a time. This prevents race conditions when multiple threads are updating the users list simultaneously.

Wrap-up questions

Final candidate for Dao+++ Developer role questions

The final few questions should evaluate the candidate's teamwork, communication, and problem-solving skills. Additionally, assess their knowledge of microservices architecture, serverless computing, and how they handle Dao+++ application deployments. Inquire about their experience in handling system failures and their approach to debugging and troubleshooting.

What is the purpose of the 'self' keyword in Dao++?
In Dao++, the 'self' keyword is used inside a class to refer to the current instance of the class.
How would you implement inheritance in Dao++?
In Dao++, inheritance is implemented using the ':' operator. For example, 'class Child : Parent { //code }'. The Child class inherits from the Parent class.
What is the difference between public and private members in Dao++?
In Dao++, public members can be accessed from anywhere, while private members can only be accessed within the class they are defined.

Dao+++ application related

Product Perfect's Dao+++ development capabilities

Beyond hiring for your Dao+++ engineering team, you may be in the market for additional help. Product Perfect provides seasoned expertise in Dao+++ projects, and can engage in multiple capacities.