Hi, I'm Sven Woltmann.

I will make you a better Java programmer.

Subscribe to my newsletter to receive regular tips about Java programming, algorithms and data structures.
Unsubscribe whenever you want. Read my Privacy Policy.
J2 Global
Unsubscribe at any time. Privacy Policy.

Discover the HappyCoders Blog

Stay up-to-date with the latest tips and tutorials about Java programming, algorithms and data structures.
Text Blocks in Java Java Text Blocks

Text blocks are a notation for multiline strings in Java. Why do we need them? How do we write and format them? Which escape sequences can or must we use?

Read more »
Java substring Method Java substring() Method

Java's String.substring() method is one of the most used Java methods ever.

How do you use the method? How does substring() work internally, and how has the implementation changed over time?

Read more »
Best books on health: nutrition, fitness, sleep Best Health Books: Nutrition, Fitness, Sleep (Updated 2022)

Recommendations and short reviews: The best books for a healthy lifestyle: healthy eating, fitness and sleep.

Read more »
Java 18 Features with Examples Java 18 Features (with Examples)

[Series: The most important new Java features from Java 10 to 18].

All new features of Java 18 with examples: UTF-8 as default character set, @snippet tag for code snippets in JavaDoc, jwebserver, Internet-address resolution SPI, and more...

Read more »
Sealed Classes in Java Sealed Classes in Java

Sealed classes and interfaces were the big news in Java 17.

What are sealed classes and interfaces? How exactly do they work? And why do we need them?

Read more »
Java 17 Features With Examples Java 17 Features (with Examples)

[Series: The most important new Java features from Java 10 to 17].

All new features of Java 17 with examples: Sealed Classes, InstantSource, HexFormat, context-specific deserialization filters, and more...

Read more »
Working with Sven really leveled up my Java and development skills! He provided invaluable guidance in all aspects of development, including concurrency, performance, reliability, and DevOps. Sven's focus on clean architecture meant our applications were simple to maintain and extend. He's always on the cutting edge of Java developments and is a pleasure to work with.
Matt Schultz
Software Engineer at HappyCo
On a professional level, Sven and I are connected by more than 20 years, several company foundations, and the implementation of some very innovative ideas in the internet sector. Sven not only had the hat of the CTO but also of the software architect and lead developer. Also, the management of larger teams has been part of his tasks.

If you want to summarize Sven's performance and get to the point, I can only think of a quote from a very well-known business angel who once said: "Sven's software is not software. It is a piece of art".
Fabien Röhlinger
Managing Director at NextPIT GmbH
I have worked with Sven for over seven years, and I have to say that he stands out among the Java developers that are around today. Sven's superb attention to detail and vast technical knowledge always provided top-quality, thoughtful, and professional outcomes in any work.

With Sven's excellent mentoring and guidance ability, I gained high impact skills in solving complex problems and reached a new level as a developer. I highly recommend him to anyone who is looking for an efficient, talented, and skilled programmer!
Daniil Tomilow
Daniil Tomilow
Senior Software Engineer Frontend at RatePAY
I had the pleasure of working with Sven for more than a year. Working with Sven means each day you learn a little more. A manager whose ability to handle multiple projects was unlikely any I had seen before and made a dramatic increase in the productivity level of our company.

Whenever I have questions or concerns, Sven responds right away and even follows up later in the week or month to make sure my issues have been resolved. His patience and willingness to help me motivated me to do the best job I can.

"Genuine expertise" is the phrase that comes to my mind when I think about Sven.
Chhavi Jain
Chhavi Jain
Quality Assurance Test Engineer at Delivery Hero