Oleksandr Andrushchenko

Oleksandr Andrushchenko

@oleksandr-andrushchenko

Software Engineer & Solution Architect

User info

Buy Me a Coffee: oleksandr.andrushchenko
Address: Missoula, MT 59808, USA
4 Followers
3 Following
35 Posts
0 Comments
Joined: Nov 03, 2025

About

Software Engineer with experience building and optimizing scalable applications across healthcare, fintech, e-commerce, media, and logistics. Skilled in Python, JavaScript/TypeScript, PHP, cloud architecture (AWS Certified Solutions Architect & Developer), and database design (RDBMS, NoSQL). Delivered 40+ projects, improving performance, scalability, and reliability. Experienced in architectural decision-making and driving projects from concept to deployment.

Latest Posts

LeetCode for System Design

LeetCode for System Design

At first glance, LeetCode problems and system design seem unrelated. One focuses on algorithms and data structures, while the other deals with distributed systems, scalability, and real-world constraints.
May 03 leetcode algorithms system-design
SQL Databases: Overview, Concepts, and Use Cases

SQL Databases: Overview, Concepts, and Use Cases

SQL databases (also known as relational databases) are systems designed to store, organize, and query structured data using a predefined schema. They are built around the relational model, where data is stored in tables and relationships between entities are explicitly defined.
Apr 30 1 sql rdbms database
SQL vs NoSQL for MVP: How to Choose the Right Database

SQL vs NoSQL for MVP: How to Choose the Right Database

Choosing between SQL and NoSQL for an MVP is one of the most common early architectural decisions — and one of the most overthought. The honest answer is still: it depends , but in practice, the decision usually comes down to two things: time to build and total cost .
Apr 29 sql nosql database
Domain Name System (DNS): Overview and Use Cases

Domain Name System (DNS): Overview and Use Cases

The Domain Name System (DNS) is a distributed naming system that translates human-readable domain names (like example.com) into IP addresses used by machines to communicate over the internet.
Apr 24 1 domain-name-system infrastructure distributed-systems
Content Delivery Network (CDN): Overview and Use Cases

Content Delivery Network (CDN): Overview and Use Cases

A Content Delivery Network (CDN) is a distributed network of servers that cache and deliver content closer to users. Instead of serving every request from a single origin server, a CDN uses geographically distributed edge locations to reduce latency and improve performance.
Apr 24 1 content-delivery-network cdn infrastructure
AWS: Overview, Purpose and Use Cases

AWS: Overview, Purpose and Use Cases

Amazon Web Services (AWS) is a cloud computing platform that provides compute, storage, networking, and database infrastructure over the internet. Instead of managing physical servers, companies consume infrastructure on-demand using a pay-as-you-go model .
Apr 22 aws cloud-computing infrastructure
CAP Theorem in Practice (Structured Overview)

CAP Theorem in Practice (Structured Overview)

CAP theorem defines three guarantees in distributed systems: consistency , availability , and partition tolerance, with the constraint that only two can be fully satisfied during a network partition. In real-world architectures, partition tolerance is unavoidable, which forces systems to choose betw
Apr 20 1 cap-theorem

ClickHouse: what is it and what is it for?

ClickHouse is an open-source, column-oriented database management system designed for online analytical processing ( OLAP ).
Apr 06 1 clickhouse olap database
ClickHouse vs PostgreSQL: Real-World Query Performance at Billion-Row Scale

ClickHouse vs PostgreSQL: Real-World Query Performance at Billion-Row Scale

This benchmark comparesPostgreSQLandClickHouseusing identical data and queries to evaluate performance in a read-heavy analytical workload. Each query was executed once. Both PostgreSQL and ClickHouse were run with default configurations (no custom tuning). The goal of this article is to demonstrate
Apr 05 1 clickhouse postgresql database

OLAP Engines Compared: Pros, Cons, and Use Cases for Modern Data Systems

Online Analytical Processing (OLAP) engines power analytical workloads involving aggregations, scans, and complex queries over large datasets. Selection impacts query latency, cost efficiency, scalability limits, and operational complexity. Different engines optimize for columnar storage, distribute
Mar 30 olap database analytics
OLAP Databases: Pros, Cons, Use Cases, and Architecture Patterns

OLAP Databases: Pros, Cons, Use Cases, and Architecture Patterns

OLAP databases(Online Analytical Processing) are optimized for complex queries, aggregations, and large-scale analytics workloads. Unlike transactional systems, they focus on read-heavy operations, enabling fast insights across massive datasets, making them essential for BI tools, reporting pipeline
Mar 30 olap database analytics
NoSQL Engines Compared: Trade-offs, Performance, and Use Cases

NoSQL Engines Compared: Trade-offs, Performance, and Use Cases

NoSQL engines provide different trade-offs inlatency, consistency, scalability, and query flexibility. Choosing the right engine requires understandingdata access patterns, workload characteristics, and operational complexity, not just database type. Choosing the right NoSQL engine directly impactsl
Mar 23 nosql database
NoSQL Databases: Types, Trade-offs, and Use Cases

NoSQL Databases: Types, Trade-offs, and Use Cases

NoSQL databases are designed to handlelarge-scale, high-velocity, and unstructured datathat traditional relational databases struggle with. They often sacrifice strict consistency forscalability, flexibility, and performance, making them ideal for modern distributed systems. Choosing the right NoSQL
Mar 22 nosql database
RDBMS (SQL) Engines: Pros, Cons, and Use Cases

RDBMS (SQL) Engines: Pros, Cons, and Use Cases

Relational Database Management Systems (RDBMS)remain foundational infrastructure in modern distributed systems because they provide strong consistency, transactional guarantees, and mature tooling for data integrity. Large-scale systems such as payment platforms, logistics networks, and SaaS product
Mar 07 1 rdbms database sql
Communication Protocols: Pros, Cons, and Use Cases

Communication Protocols: Pros, Cons, and Use Cases

Modern distributed systems rely on communication protocols that define how services exchange data. As a software developer designing APIs, microservices, real-time systems, or event-driven platforms, choosing the correct protocol directly impacts latency, scalability, observability, cost, and develo
Feb 23 1 protocols
Building Multi-Tenant Support in a User-Based SaaS App (case study)

Building Multi-Tenant Support in a User-Based SaaS App (case study)

Many SaaS applications begin with a very simple idea: one user signs up, creates data, and owns that data. This model works extremely well in the early stages of a product. It is easy to reason about, easy to implement, and easy to secure. However, as the product grows, a common requirement appears:
Feb 14 saas case-study rdbms
Amazon DynamoDB: Pros, Cons, and Use Cases

Amazon DynamoDB: Pros, Cons, and Use Cases

Amazon DynamoDB is a fully managed NoSQL key–value and document database service provided by AWS . It is designed to deliver single-digit millisecond performance at virtually any scale, without requiring developers to manage servers, storage, or replication.
Jan 24 dynamodb aws nosql
DynamoDB Data Modeling: Blog Platform Example (case study)

DynamoDB Data Modeling: Blog Platform Example (case study)

This case study describes a production blog platform backed entirely by Amazon DynamoDB . The system serves typical blog workloads such as “latest posts”, “most popular posts”, “posts by author”, and “posts by tag”, while also supporting administrative queries like user moderation and contact messag
Jan 19 3 dynamodb database nosql
Availability patterns

Availability patterns

Availability patternsdescribe architectural techniques that keep systems operational despite failures, overload, or partial outages. High availability matters most in systems that support continuous business processes, such as payment authorization or customer-facing APIs, where downtime directly tr
Jan 05 availability fault-tolerance high-availability
Consistency patterns

Consistency patterns

Consistency patternsdescribe how systems behave when multiple actors read and write shared data, especially under concurrency, failure, or distribution. Database transactions are one of the strongest tools for enforcing consistency, but they coexist with weaker models that trade correctness guarante
Dec 29, 2025 1 consistency
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