Around IT in 256 seconds
Podcast for developers, testers, SREs... and their managers. I explain complex and convoluted technologies in a clear way, avoiding buzzwords and hype. Never longer than 4 minutes and 16 seconds. Because software development does not require hours of lectures, dev advocates' slide decks and hand waving. For those of you, who want to combat FOMO, while brushing your teeth. 256 seconds is plenty of time. If I can't explain something within this time frame, it's either too complex, or I don't understand it myself.
By Tomasz Nurkiewicz. Java Champion, CTO, trainer, O'Reilly author, blogger
Kategorie:
Technologia
Technologia
#57: Kotlin: Much more than 'better Java'
2021-11-16 09:11:01
Kotlin is a programming language that runs mainly on Java Virtual Machine. This means it’s fully interoperable with Java and even other JVM languages. Developers can gradually rewrite their applications from Java to Kotlin. Or use Java libraries and frameworks inside Kotlin. But why bother with a new language? Kotlin has plenty of improvements over good old Java. Sometimes it’s placed between Java and Scala in terms of capabilities. It seems more modern, agile, and powerful.
Read more: https://nurkiewicz.com/57
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Kotlin is a programming language that runs mainly on Java Virtual Machine. This means it’s fully interoperable with Java and even other JVM languages. Developers can gradually rewrite their applications from Java to Kotlin. Or use Java libraries and frameworks inside Kotlin. But why bother with a new language? Kotlin has plenty of improvements over good old Java. Sometimes it’s placed between Java and Scala in terms of capabilities. It seems more modern, agile, and powerful.
Read more: https://nurkiewicz.com/57
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#56: Test-driven development: It's not about testing
2021-11-02 09:59:28
Test-driven development (TDD for short) means developing software by writing tests first. I hope you all write unit and integration tests. But do you write them before the actual production code? This approach to software development is just that. You must write a failing test first. And you are not allowed to write even a single line of production code without a failing test. Think about it. If all your tests are green, it is forbidden to write production code. Everything must start from a red test.
Read more: https://nurkiewicz.com/56
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Test-driven development (TDD for short) means developing software by writing tests first. I hope you all write unit and integration tests. But do you write them before the actual production code? This approach to software development is just that. You must write a failing test first. And you are not allowed to write even a single line of production code without a failing test. Think about it. If all your tests are green, it is forbidden to write production code. Everything must start from a red test.
Read more: https://nurkiewicz.com/56
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#55: Percentages, percentage points and basis points: understand your metrics
2021-10-25 22:20:30
You might find this topic weird, but understanding percentages is crucial not only in banking. What does it mean when disk space decreased by 10 percent? How to scientificly measure relative system load? And how to sound smart when applying for mortgage? You’ll learn all that in the next four minutes.
Read more: https://nurkiewicz.com/55
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You might find this topic weird, but understanding percentages is crucial not only in banking. What does it mean when disk space decreased by 10 percent? How to scientificly measure relative system load? And how to sound smart when applying for mortgage? You’ll learn all that in the next four minutes.
Read more: https://nurkiewicz.com/55
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#54: Immutability: from data structures to data centers
2021-10-19 08:49:57
Immutability means that when something was once created, it can’t be changed. This concept is tremendously important across our whole industry. Probably you’ve heard about immutable data structures. Let’s take an immutable list as an example. If you create such a list with a few items, you can’t add more items to that list. It’s written in stone. Any action attempting to modify that list returns a modified copy. The original instance is left intact. Modifying a single item, adding or removing, sorting - each of these operations return a copy.
Read more: https://nurkiewicz.com/54
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Immutability means that when something was once created, it can’t be changed. This concept is tremendously important across our whole industry. Probably you’ve heard about immutable data structures. Let’s take an immutable list as an example. If you create such a list with a few items, you can’t add more items to that list. It’s written in stone. Any action attempting to modify that list returns a modified copy. The original instance is left intact. Modifying a single item, adding or removing, sorting - each of these operations return a copy.
Read more: https://nurkiewicz.com/54
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#53: CDN: Content Delivery Network: global scale caching
2021-10-11 22:30:16
CDN is a set of geographically distributed servers for fast content delivery. Without CDN all requests are routed to your own server, located somewhere in the world. For example, in San Francisco. If your visitor lives in Australia, the experience is rather poor. But now imagine the traffic to your website is proxied through a global caching layer. Your visitor in Australia downloads data from an edge server nearby. A different visitor in Cape Town, Africa, will be routed to a completely different CDN server. The routing is done by the CDN itself, typically via DNS. It’s transparent to your visitors. Of course, all CDN servers contain the same data. Moreover, pretty much no-one contacts your own server in San Francisco. Only the CDN network itself. Technically, visitors don’t even know the address of your origin server! They use domain name like example.com and DNS routes to appropriate cache server.
Read more: https://nurkiewicz.com/53
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CDN is a set of geographically distributed servers for fast content delivery. Without CDN all requests are routed to your own server, located somewhere in the world. For example, in San Francisco. If your visitor lives in Australia, the experience is rather poor. But now imagine the traffic to your website is proxied through a global caching layer. Your visitor in Australia downloads data from an edge server nearby. A different visitor in Cape Town, Africa, will be routed to a completely different CDN server. The routing is done by the CDN itself, typically via DNS. It’s transparent to your visitors. Of course, all CDN servers contain the same data. Moreover, pretty much no-one contacts your own server in San Francisco. Only the CDN network itself. Technically, visitors don’t even know the address of your origin server! They use domain name like example.com and DNS routes to appropriate cache server.
Read more: https://nurkiewicz.com/53
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#52: How computers work: from electrons to Electron
2021-10-04 22:15:46
Today I’d like to explain how computers work. From the ground up, grossly simplifying. It all starts with an electric field. It’s a place where charged particles, like electrons, are attracted or repelled. The electricity flows through a piece of wire because of the difference in electric field potential on wire’s ends. This difference is known as voltage.
Read more: https://nurkiewicz.com/52
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Today I’d like to explain how computers work. From the ground up, grossly simplifying. It all starts with an electric field. It’s a place where charged particles, like electrons, are attracted or repelled. The electricity flows through a piece of wire because of the difference in electric field potential on wire’s ends. This difference is known as voltage.
Read more: https://nurkiewicz.com/52
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#51: Cloud computing: more than renting servers per minute
2021-09-28 00:00:00
Cloud computing is a broad term. In general, it refers to using hardware and software managed by someone else. Typically with very flexible pricing: we only pay for what we use and for the time we use it. We don’t build data centers ourselves. We don’t buy large servers and provision them. We simply rent a server on a per-minute basis. The cloud provider has a pool of servers and they are reused and recycled. Once we are done, we no longer pay and some other customer can use that same server. Just like we don’t own a taxi. We barely pay for kilometers and minutes. When the server breaks for some reason, the provider takes care of repairs and replacements. We simply, almost transparently, get a new machine.
Read more: https://nurkiewicz.com/51
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Cloud computing is a broad term. In general, it refers to using hardware and software managed by someone else. Typically with very flexible pricing: we only pay for what we use and for the time we use it. We don’t build data centers ourselves. We don’t buy large servers and provision them. We simply rent a server on a per-minute basis. The cloud provider has a pool of servers and they are reused and recycled. Once we are done, we no longer pay and some other customer can use that same server. Just like we don’t own a taxi. We barely pay for kilometers and minutes. When the server breaks for some reason, the provider takes care of repairs and replacements. We simply, almost transparently, get a new machine.
Read more: https://nurkiewicz.com/51
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#50: Property-based testing: find bugs automatically by generating thousands of test cases
2021-09-21 09:16:13
Property-based testing is an approach to automatically test software against well-defined rules. We don’t specify desired output for a few inputs. Instead, we barely define properties that should always hold. It’s best explained with an example. How do you make sure that your compression algorithm works? Ordinary unit tests verify a handful of inputs that you came up with. If you are experienced developer, you will include edge cases. I mean, the weirdest inputs, like an empty string or a long sequence of the same character. And what are the properties of a good compression algorithm? Its output should takes less space, obviously. But even more importantly, lossless algorithm should be capable of decompression. What if I told you, there is software that can check these properties automatically? With thousands of randomized tests?
Read more: https://nurkiewicz.com/50
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Property-based testing is an approach to automatically test software against well-defined rules. We don’t specify desired output for a few inputs. Instead, we barely define properties that should always hold. It’s best explained with an example. How do you make sure that your compression algorithm works? Ordinary unit tests verify a handful of inputs that you came up with. If you are experienced developer, you will include edge cases. I mean, the weirdest inputs, like an empty string or a long sequence of the same character. And what are the properties of a good compression algorithm? Its output should takes less space, obviously. But even more importantly, lossless algorithm should be capable of decompression. What if I told you, there is software that can check these properties automatically? With thousands of randomized tests?
Read more: https://nurkiewicz.com/50
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#49: Functional programming: academic research or new hope for the industry?
2021-09-14 00:08:45
Functional programming means programming using functions. See, I need much less than 256 seconds for that! Unfortunately, this definition is as useful as saying that object-oriented programming means programming with objects. So let’s dive deeper. First of all, I mean pure functions as defined by mathematicians. In math, a function always returns the same output for a given input. A length of a string is a function. A form validator is typically a function as well. For the same form inputs it always returns the same result: valid or invalid. On the other hand, returning the current date for a given location is not a function. Or reading a file.
Read more: https://nurkiewicz.com/49
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Functional programming means programming using functions. See, I need much less than 256 seconds for that! Unfortunately, this definition is as useful as saying that object-oriented programming means programming with objects. So let’s dive deeper. First of all, I mean pure functions as defined by mathematicians. In math, a function always returns the same output for a given input. A length of a string is a function. A form validator is typically a function as well. For the same form inputs it always returns the same result: valid or invalid. On the other hand, returning the current date for a given location is not a function. Or reading a file.
Read more: https://nurkiewicz.com/49
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#48: Distributed tracing: find bottlenecks in complex systems
2021-09-07 09:38:33
Life used to be simple. In a traditional monolithic application, when a failure occurred, you could easily find the
problem. When an exception bubbles up, it appears throughout all stack frames. You can easily examine which methods
or functions were invoked from each other. You can see application layers involved. Moreover, it’s fairly easy
to profile performance bottlenecks. Answering these questions becomes much harder when there are multiple systems
involved.
Read more: https://nurkiewicz.com/48
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Life used to be simple. In a traditional monolithic application, when a failure occurred, you could easily find the problem. When an exception bubbles up, it appears throughout all stack frames. You can easily examine which methods or functions were invoked from each other. You can see application layers involved. Moreover, it’s fairly easy to profile performance bottlenecks. Answering these questions becomes much harder when there are multiple systems involved.
Read more: https://nurkiewicz.com/48
Get the new episode straight to your mailbox: https://nurkiewicz.com/newsletter