• The Swift programming language was originally developed by Chris Lattner at Apple, Inc. and first announced alongside iOS 8 at Apple’s Worldwide Developer Conference in 2014.
• Swift has standard libraries that make writing code intuitive and efficient. It the uses LLVM compiler technology.
• Swift was developed to tackle the challenges of Objective-C, a programming language used for iOS development. The language is currently used for products with iOS 7 as well as MacOS 10.9 or higher.
• Swift is a successor to both the C and Objective-C languages. It includes low-level primitives such as types, flow control, and operators. It also provides object-oriented features such as classes, protocols, and generics.

• Swift adopts safe programming patterns and adds modern features to make programming easier, more flexible, and more fun. Swift’s clean slate, backed by Cocoa and Cocoa Touch frameworks is an opportunity to revolutionize software development.
• An advantage of Swift for businesses is that if the business decides to introduce an Android-based application for their customers - Swift, unlike Objective-C, isn’t completely unique to the iOS platform and is related to other coding languages in the market.

The following are some of the tools used by Swift developers at various stages of development:

1. IDE and Editors

• XCode - is Apple's original IDE that provides developers a unified workflow for user interface design, coding, testing, and debugging.
• CodeRunner - IDE known for its code compiling ability and is used to develop advanced applications.

Backend Services

• Parse - Tool that provides service-as-a-backend. It is an open-source platform by Facebook.

2. Testing Tool

• TestFlight - Beta testing tool by Apple that allows invited users to test, provide feedback and get updates about the developer's application.

3. Documentation Tool

• Jazzy - one of the easiest documentation tools for Swift, known for its accurate result.
• Dash - is a documentation browser and code snippet manager which can search offline documentation.

4. Plugins

• Puckham - is a plugin for XCode which saves time by simplifying adding #import-s from anywhere in the code.

Below are some key points that we at Flexiple have learned through trial and error - a process of filtering through over 15,000 developers. You can use these in your process to hire Swift developers.

• Years of software development experience: Be specific about the technology you’re looking for and the number of years of experience needed. A proxy to years of experience can be the number of production-level apps worked on.
• Type of products built in the past: Based on the type of product you are trying to build - social network, SAAS product, etc. - you can prioritize certain developers over others.
• Exposure to specific industries: Developers who have built products in certain industries will already know key aspects of laying the foundation for a great product and will be able to predict possible problems.
• Experience working remotely: A developer with past remote work experience is an added advantage as they would have first-hand experience of everything - right from how contracts work to streamlined communication, as well as timelines and deliverables.
• Strong communication: An essential thing to look at when hiring a freelancer is excellent communication skills. Since all the interaction happens online, a freelancer should be able to effectively communicate to ensure a streamlined execution of all work.

Now that you have made a quality JD, it can still be tricky to evaluate the skills of your applicants when you hire Swift developers. To help you with that, we have created a pool of questions that a good software developer should be comfortable with.

It is important to note that the ability to answer these questions doesn't imply that you have a top quality candidate. But it definitely is a big step in that direction.

To help you navigate through these questions, we’ve categorized the interview questions in 3 parts:

A. Basic concepts: Includes all basic concepts used across languages but we've focused on their significance in Swift. This will give you an understanding of how strong their programming foundation is.

B. Advanced concepts: Includes all concepts that someone with higher expertise should know.

C. DS/Algorithm questions: To test the logical capability of the candidate.

A. Basic concepts

Coming soon!

B. Advanced concepts

Coming soon!

C. Data Structure/ Algorithm

1. Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct order. Note that an empty string is also considered valid.

class ValidParenthesesFunc {
    func isValid(_ s: String) -> Bool {
        var stc = [Character]()

        for char in s {
            if char == "(" || char == "[" || char == "{" {
                stc.append(char)
            } else if char == ")" {
                guard stc.count != 0 && stc.removeLast() == "(" else {
                    return false
                }
            } else if char == "]" {
                guard stc.count != 0 && stc.removeLast() == "[" else {
                    return false
                }
            } else if char == "}" {
                guard stc.count != 0 && stc.removeLast() == "{" else {
                    return false
                }
            }
        }
        return stc.isEmpty
    }
}

The above code will input 0(false). 

2. What will the output of the following code be?

$x = 10;
$y = 5;
$z = 3;
if ($x / $y / $z)
    print "hi";
else
    print "hello";

a) hi
b) hello
c) error
d) no output

The answer is A because the floating-point division returns a non zero value = 0.66 which evaluates 
to true and outputs ‘hi’.

3. What will the output of the following code be?

$x = 2
$y = 4
$z = 6
if($z > $y > $x) {
    echo “true”;
}else{
    echo “false”;
}

The answer is False. It may look like the output can be true because 6 > 4 > 2 is true, but PHP evaluates $z > $y 
first, which returns a boolean value of 1 or true. This value (true or 1) is compared
to the next integer in the chain, bool(1) > $z, which will result in NULL and echo “false.”

As discussed, it isn't easy to find a quality freelance software developer but this guide makes the process easier for you. To offload the entire hiring process, reach out to us at Flexiple. We've designed a high-quality, 6-step screening process to find the top 1%, freelance developers. You can find the best freelance Swift developers here. We've already served over a hundred clients, earning great reviews for the quality of service.

Lastly, to quickly summarize it for you:

• Note your project requirements and hire accordingly. Do not go for the lowest or the highest-paid developer.
• Don’t hire without vetting- consider asking questions right from the basics to advanced to logical questions.
• Look for companies like Flexiple that help you find the perfect fit.

That is everything you need to know about for when you want to hire Swift developers. Happy hiring! :)