How statistics are calculated
We count how many offers each candidate received and for what salary. For example, if a Data QA developer with XML with a salary of $4,500 received 10 offers, then we would count him 10 times. If there were no offers, then he would not get into the statistics either.
The graph column is the total number of offers. This is not the number of vacancies, but an indicator of the level of demand. The more offers there are, the more companies try to hire such a specialist. 5k+ includes candidates with salaries >= $5,000 and < $5,500.
Median Salary Expectation – the weighted average of the market offer in the selected specialization, that is, the most frequent job offers for the selected specialization received by candidates. We do not count accepted or rejected offers.
Trending Data QA tech & tools in 2024
Where is XML used?
Config Files: The Tidy Cupboard!
- Software settings love to chill in XML's neat drawers, like a well-organized sock drawer for developers.
Soap Opera of Services
- SOAP protocols gossip in XML messages like a postal service for chatty web services.
Ancient Scrolls of Data Exchange
- Before JSON muscled in, XML was the elder statesman for data sharing, trading bits like vintage baseball cards.
The X Marks the Spot
- In the treasure hunt of office templates, XML maps the way to riches in Microsoft Office file formats.
XML Alternatives
JSON (JavaScript Object Notation)
JSON is a lightweight data-interchange format. It's easy for humans to read and write, and easy for machines to parse and generate. Used primarily to transmit data between a server and web application.
{
"name": "John",
"age": 30,
"isStudent": false
}
- Human-readable and writtable
- Lightweight, leading to faster processing
- Widely supported across programming languages
- Lacks support for comments
- No support for namespaces
- Can be verbose for complex structures
YAML (YAML Ain't Markup Language)
YAML is a human-friendly data serialization standard for all programming languages. It's often used for configuration files and in data exchange where human readability is important.
name: John
age: 30
isStudent: false
- Highly readable syntax
- Supports complex data structures
- Uses indentation for scope
- Prone to errors due to indentation
- Can be slow to parse in large quantities
- Lacks security features by default
Protocol Buffers (Protobuf)
Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data, similar to XML but smaller, faster, and simpler. Used for storing and exchanging structured information.
message Person {
required string name = 1;
required int32 age = 2;
optional bool is_student = 3;
}
- Compact and efficient serialization
- Schema-based with clear contracts
- Backward and forward compatibility
- Requires pre-defined schema
- Not human-readable format
- Smaller ecosystem compared to JSON and XML
Quick Facts about XML
XML: The Hierarchical Heavyweight That Outgrew Its SGML Sibling
Picture it: 1996, the year the Spice Girls were telling us what they "really, really want" and the tech world got what it really, really needed – XML! Conceived as a simplified subset of SGML, XML was designed by a ten-member gang called the XML Working Group, helmed by its captain, Jon Bosak. They sought to make this data structuring and transportation champ both human and machine-readable, which is kind of like making broccoli taste like chocolate – ambitious but oh, so beneficial.
<note>
<to>Developer</to>
<from>XML</from>
<heading>Hello, World!</heading>
<body>Don't forget to validate me!</body>
</note>
XML Speaks in Tongues: Namespaces and X-Words
Fast forward a couple of years to 1999, a world nervously peeking at Y2K, and XML 1.0 was spreading like the latest cat meme. But one set of tags wasn't enough to hold the convos across different XML vocabularies. Enter Namespaces in XML – not about outer space, but just as cool. This meant XML could play nice with HTML without overstepping tag boundaries. And with XSLT, XPath, and XQuery joining the party, XML had more X's than a pirate's treasure map!
<html:div xmlns:html="http://www.w3.org/1999/xhtml">
<music:song xmlns:music="http://www.music.org">
<music:title>Code Me Maybe</music:title>
<music:artist>Carly Debug Jepsen</music:artist>
</music:song>
</html:div>
XML 1.1: When It Decided to Get a Makeover
Let's zoom to 2004. Usher's 'Yeah!' was topping the charts, and XML was getting an upgrade to 1.1. And just like low-rise jeans, not everyone was thrilled about the change. This version tweaked character encoding and made it simpler to include special characters. Basically, XML went from the tech equivalent of a flip phone to a smartphone – more features, more emojis, but not everyone wanted to relearn how to text!
<message>
<text>Hello, 😎 World!</text>
</message>
What is the difference between Junior, Middle, Senior and Expert XML developer?
Seniority Name | Experience | Average Salary (USD/year) | Responsibilities & Activities |
---|---|---|---|
Junior XML Developer | 0-2 years | $50,000 - $70,000 |
|
Middle XML Developer | 2-5 years | $70,000 - $90,000 |
|
Senior XML Developer | 5-10 years | $90,000 - $110,000 |
|
Expert/Team Lead XML Developer | 10+ years | $110,000+ |
|
Top 10 XML Related Tech
Java/C#
Like peanut butter and jelly, Java and C# are the classic sandwich spread for XML manipulation – they're the bread-and-butter languages that play nice with XML right out of the box. Java has libraries like JAXB that can marshal and unmarshal XML faster than a cowboy at a rodeo, and C# has LINQ to XML that lets you query your XML documents as if they were SQL-database socialites at a high-tea event.
// Java example JAXB
Unmarshaller unmarshaller = JAXBContext.newInstance(YourClass.class).createUnmarshaller();
YourClass yourClassInstance = (YourClass) unmarshaller.unmarshal(new File("path/to/your/xmlfile.xml"));
// C# example LINQ to XML
XDocument xmlDoc = XDocument.Load("path/to/your/xmlfile.xml");
IEnumerable<XElement> rows = from row in xmlDoc.Descendants("row") select row;
XML Schema
The blueprint of the XML world – if your XML were a LEGO structure, XML Schema would be the instruction booklet, ensuring that each piece clicks exactly where it should. It defines the structure and types of data allowed, making it the strict librarian of the XML data files, always shushing incorrect formats.
// XML Schema example
<xs:element name="contact">
<xs:complexType>
<xs:sequence>
<xs:element name="name" type="xs:string"/>
<xs:element name="phone" type="xs:string"/>
</xs:sequence>
</xs:complexType>
</xs:element>
XSLT
XSLT is like the DJ of XML files, remixing and splicing together XML documents to produce a fresh new track... or in this case, a brand spanking new HTML, text, or another XML document. With XSLT, transform your data like a magical origami master folding paper swans.
// XSLT example
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<html>
<body>
<h2>My CD Collection</h2>
<table border="1">
<xsl:for-each select="catalog/cd">
<tr>
<td><xsl:value-of select="artist"/></td>
<td><xsl:value-of select="title"/></td>
</tr>
</xsl:for-each>
</table>
</body>
</html>
</xsl:template>
</xsl:stylesheet>
XPath
XPath is the treasure map to your XML's gold – with it, point out the exact location of data in an XML document with the precision of a GPS system on a secret agent's car. It's like Where's Waldo, but your Waldo sticks out like a sore thumb.
// XPath example
String expression = "/class/student[@rollno='493']";
Node studentNode = (Node) xPath.compile(expression).evaluate(xmlDocument, XPathConstants.NODE);
XQuery
Picture a private investigator rifling through a drawer – that's XQuery in the XML database. It's almost synonymous with "Where's the beef?" but for data in XML documents, allowing you to extract the meaty information bits you actually care about.
// XQuery example
for $x in doc("yourdata.xml")//yourElement
where $x/yourSubElement = "value"
return $x
XML DOM
The XML DOM is your XML document’s family tree, but instead of Uncle Bob and Aunt Sue, you have nodes and elements as relatives. It lets you navigate and manipulate these family gatherings using JavaScript, turning you into the ultimate family planner.
// XML DOM example in JavaScript
var xmlDoc = parser.parseFromString(text,"text/xml");
xmlDoc.getElementsByTagName('title')[0].childNodes[0].nodeValue = "New Title";
SAX (Simple API for XML)
SAX is like speed dating for XML parsers – instead of getting cozy with the whole document, it darts through elements firing events, making it a memory-efficient choice for playing the XML field if you're tight on memory budget.
// SAX example
class UserHandler extends DefaultHandler {
public void startElement(String uri,
String localName, String qName, Attributes attributes) throws SAXException {
if (qName.equalsIgnoreCase("book")) {
String isbn = attributes.getValue("isbn");
}
}
}
Apache Camel
Apache Camel is like the Switzerland of application integrations, a peacekeeper that lets different systems talk in XML without throwing punches. It's an integration framework that routes XML messages between APIs like a postal service on steroids.
// Apache Camel routing example
from("file:data/inbox")
.process(new MyTransformer())
.to("jms:queue:order");
SOAP Web Services
The postage stamp on your envelope of data, SOAP envelopes XML web service requests and ensures they’re delivered properly. It's a protocol more formal than a penguin at a gala event, ensuring messages are formatted and transmitted with the decorum of a butler carrying a silver tray.
// SOAP request example
POST /InStock HTTP/1.1
Host: www.example.org
Content-Type: text/xml; charset=utf-8
Content-Length: length
SOAPAction: "http://www.w3.org/2001/12/soap-envelope"
<soap:Envelope xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
<soap:Body xmlns:m="http://www.example.org/stock">
<m:GetStockPrice>
<m:StockName>AAPL</m:StockName>
</m:GetStockPrice>
</soap:Body>
</soap:Envelope>
XML-RPC
Think of XML-RPC as your grandma's telegraph system, albeit less old-timey and more internet-friendly. This protocol allows remote procedure calls encoded in XML, letting software on different operating systems talk easily like pen pals from the '90s.
// XML-RPC request example
<?xml version="1.0"?>
<methodCall>
<methodName>methodNameHere</methodName>
<params>
<param><value><int>42</int></value></param>
</params>
</methodCall>