Development

Why did I write this article?

When I was preparing for Java 8 OCA and OCP I found a lot of useful articles about subjects on Habr that helped me to choose the optimal path and save a considerable amount of time.

When I started preparing for OCA Oracle Database SQL (1Z0-071) I didn’t find any materials on Habr about this matter and found there to be limited information available on the Internet. Because of this I decided to write a complete guide in order to help others who are interested in this certification to help them save time and successfully pass what I consider to be a pretty hard exam.

In this article, I would like to propose an alternative to the traditional test design style using functional programming concepts in Scala. This approach was inspired by many months of pain from maintaining dozens of failing tests and a burning desire to make them more straightforward and more comprehensible.

Even though the code is in Scala, the proposed ideas are appropriate for developers and QA engineers who use languages supporting functional programming. You can find a Github link with the full solution and an example at the end of the article.

We used to think of Telegram as a reliable and secure transmission medium for messages of any sort. But under the hood it has a rather common combination of a- and symmetric encryptions. Where’s fun in that? And why would anyone trust their private messages to a third-party anyway?

TL;DR — inventing a private covert channel through users blacklisting each other.

Have you heard about memoization? It's a super simple thing, by the way,– just memoize which result you have got from a first function call, and use it instead of calling it the second time - don't call real stuff without reason, don't waste your time.

Skipping some intensive operations is a very common optimization technique. Every time you might not do something — don’t do it. Try to use cache — memcache, file cache, local cache — any cache! A must-have for backend systems and a crucial part of any backend system of past and present.

How Tax Service, OpenStreetMap, and InterSystems IRIS
could help developers get clean addresses

I like PHP for development speed and excellent portability. It's great to have such a tool in your pocket, always ready to solve problems.

For me it was quite sad that there was no Waves Platform SDK for PHP when i first met this nice blockchain. Well, I had to write such kit.

Here I describe the results of developing a PostgreSQL extension I built just out of curiosity. Its purpose is to automatically manage extended column statistics. The idea came to me while finishing work on another "smart" query-driven product for improving PostgreSQL planning quality. I realized that the current architecture of PostgreSQL isn’t quite ready for fully autonomous operation — automatic detection of bad plans and adaptive optimizer tuning. So why not try the other way around and build an autonomous data-driven assistant?

Hi everyone, I’m Alexey. I’m a big fan of observability, and in this post, I want to share something I’ve been working on — the pgpro-otel-collector.

TL;DR: pgpro-otel-collector is an OpenTelemetry collector (aka monitoring agent) tailored for gathering Postgres metrics and logs — brought to you by PostgresPro.

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This article presents a business-driven approach to software architecture, focusing on maximizing profitability through technical decisions. It advocates for:

Distributed, stateless services with immutable models for scalability

Isolated third-party integrations without disrupting core logic

Simple, modular design 

Best for:

✔ Tech leads designing scalable systems
✔ Managers optimizing dev efficiency
✔ Stakeholders evaluating ROI on architecture