When I first learn about kubernetes, I use a lot of terminal screen and kubectl commands. The same way happened for istio, the kubernetes service mesh. Both are powerful items, and we can create declarative configuration for both using yaml files and kubectl commands. …

There are so many links out there who explains about encryption, particularly symmetric encryption using AES, and asymmetric encryption using RSA. For the sake of coding implementation, I will re-write them here, as simple (and short) as possible. There are basically some important terms: # Encryption you want to provide…

Apache kafka is good, and having kafka stream is great for transforming data stream as they arrived. Extend those items further, and we will get KsqlDB. KsqlDB basically is ”SQL for Kafka”. …

Business user requirement usually involves complex workflow. For example: request user input to do process A If user input is I1, go to process B. If input is I2, go to process B. Otherwise, request another input on process C On process B, do sub-process B1, B2, and approval using…

When we have APIs deployed, we should test it against multiple test cases (positive & negative). For each test, we should also know the result, whether test case failed or passed. If you are using agile & Jira, likely you familiar with creating user stories at Jira. But Jira is…

What is Cache? Cache is temporary storage to speed up performance. At times, we might have data that frequently used. For example, a function need interest rate based on loan period (tenure). In database, you might have table like this (simplified): If your logic need to process total loan, with…

What Is Graph? I am graph, I go to work on graph. It’s everywhere, really. I have a sister. Both of us has same parents. Our mom has parents, which is our grandparents from mom’s side. And so our dad, which means we have grandparents from dad’s side. …

Kafka has good integration with Java spring, as you can see here. Spring provides KafkaTemplate and annotations to easily produce and consume kafka. But not everybody uses Spring. Sometimes even team working on other programming language than java. This means, learning kafka needs another learning curve, especially when uses native…

Disclaimer : This article is my opinion and NOT represents point of view of my current or former employers. Despite the usual, this is NOT technical article, so feel free to see my other articles if you’re looking for it. Open banking, open finance (not to be confused with open…