, Index Performance
, Document Store
, Log Parser
, Driver Exam
, Crop Ratio
, Programmer Teacher
, Employee Manager
, Chain Link
, Read First Line
, Cheapest Product
, Movies Live
, ATM Locations
, Delete Orders
, Restaurant Menu
, Student Activities
, Youngest Child
, Internal Nodes
, Moving Total
, Unique Numbers
, Remove Repetitions
, Max Sum
, Unique Name
, Paper Strip
, Weighted Average
, Test Results
, Bank Branches
, Hospital Patients
, Menu Items
, Ban Users
, Unloading Trucks
, Stack to List
, Read Write Execute
, Shining Star
, SMS Messages
, Document Counter
, Snow Storm
, Student Max Score
, Shelf Test
, Department Report
, Merge Stock Index
, Date Transform
The Java programming language is a simple, modern, general-purpose, object-oriented programming language. Having a basic familiarity with the programming language used on the job is a prerequisite for quickly getting up to speed.
Object-oriented programming is a paradigm based on encapsulating logic and data into objects, which may then contain fields and procedures. Many of the most widely used programming languages are based on OOP, making it a very important concept in modern programming.
SQL is the dominant technology for accessing application data. It is increasingly becoming a performance bottleneck when it comes to scalability. Given its dominance, SQL is a crucial skill for all engineers.
An aggregate function is typically used in database queries to group together multiple rows to form a single value of meaningful data. A good programmer should be skilled at using data aggregation functions when interacting with databases.
Subqueries are commonly used in database interactions, making it important for a programmer to be skilled at writing them.
The proper implementation and use of indexes are important for improving the performance of database queries.
Conditional statements are a feature of most programming and query languages. They allow the programmer to control what computations are carried out based on a Boolean condition.
Everyone makes mistakes. A good programmer should be able to find and fix a bug in their or someone else's code.
A programmer should use a language as a tool, always taking advantage of language-specific data types and built-in functions.
A stream is a sequence of data elements made available over time. It is particularly useful for tasks that may benefit from being asynchronous, including tasks such as I/O processing or reading from a file, and as such is important for developers to understand.
The string data structure is used to represent text. It is one of the most commonly used data structures. Therefore, every programmer should be skilled at string manipulation.
Familiarity with data serialization to and from formats such as XML and JSON is important as it is commonly used for interprocess communication
Exceptions exist in most modern programming languages, making it important for a programmer to understand them and know how to handle them.
Even though most database insert queries are simple, a good programmer should know how to handle more complicated situations like batch inserts.
A normalized database is normally made up of multiple tables. Joins are, therefore, required to query across multiple tables.
Choosing the right data structure to solve a problem can have huge implications on the performance of an application. Knowing when to use a specific data structure is one of the most important skills for a programmer.
An array is a container of a fixed number of objects of a similar type. It is a fundamental component of most programming languages.
Iteration is the act of repeating a process, or cycling through a collection. Iteration is one of the fundamental flow control tools available to developers.
Arithmetic is a fundamental branch of mathematics. An understanding of arithmetic concepts, and their application, is important for every candidate.
Multi-threading allows a process to make more efficient use of modern hardware by allowing code to execute asynchronously. It can drastically improve the performance of any app; however, it can be tricky to get right, making this an important topic for any programmer.
Constraints are used to define rules and relationships. They are applied to a dataset. A constraint may take many forms, such as x ≤ 5 in a programming language and a NOT NULL constraint in a SQL table definition.
A database schema defines how data is stored in a database. An SQL database uses a schema to define tables consisting of rows and columns that use fixed data types to store data. Formalizing how data is stored is the first step towards building an application or service.
The delete statement is used to delete records in a table and is one of the four basic CRUD functions (create, read, update, and delete) required for working with any persistent storage.
The UPDATE statement is used to modify the existing records in a table and is one of the most used operations for working with the database.
A database view is a result set that is defined by a stored query, the results of which can can also be queried. As a fundamental and widely used database construct, it's useful for candidates to understand how and when they should be used.
When designing and/or analyzing an algorithm or data structure, it is important to consider the performance and structure of an implementation. Algorithmic thinking is one of the key traits of a good programmer, especially one working on complex or performance-critical code.
Every programmer should be familiar with data-searching methods, as they are very common in data-analysis processes.
Many real-life situations are best modeled by graphs. Therefore, an in-depth knowledge of graph data structures is important for a good programmer.
Memory management allows programs to request memory dynamically from the operating system, and free it for reuse when no longer needed. Many modern programming languages automate this process; however, it should still be an important consideration when implementing an application.
The performance of an application or system is important. The responsiveness and scalability of an application are all related to how performant an application is. Each algorithm and query can have a large positive or negative effect on the whole system.
The process of restructuring existing computer code without changing its external behavior. It is essential for keeping code readable and maintainable.
Every programmer should be familiar with data-sorting methods, as sorting is very common in data-analysis processes.
Test case design
Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle: requirements are turned into very specific test cases, based on which the software is improved only in order to pass the new tests. TDD is an essential skill for modern programmers.
Test case design
Being able to create a set of test cases that ensure adequate test coverage is a key skill for creating a successful test. It is desirable for the test suite also to be optimal, i.e. to minimize test execution effort and time without affecting the test coverage.
Dynamic programming methods for code optimization can be very useful to a programmer who understands them.
In mathematics, a union typically involves testing if an element exists in two or more sets. This definition also applies as an operator and function in various programming languages. As one of the most common collection operations, alongside intersection, it's an important topic for any candidate to understand.