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Mert Özen's blog posts on software development, backend, frontend, and DevOps.

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.NET Core Web API 36 Angular 31 JavaScript Basics 19 JavaScript Intermediate 18 JavaScript Advanced 16 TypeScript Basics 14 TypeScript Intermediate 14 TypeScript Advanced 12 Entity Framework Core 28 Dapper 16 Git & GitHub 29 Web Security (OWASP Top 10) 21 LLM Fundamentals 20 C# Fundamentals 20 Object-Oriented Programming in C# 16 C# Collections and Generics 11 LINQ 17 Asynchronous Programming in C# 17 Advanced C# 14 C# Versions 6 Solution Patterns 22 SOLID and Design Principles 12 Clean Code 13 Design Patterns 23 UML and Modeling 18 Introduction to Software Architecture 9 Clean, Onion and Hexagonal Architecture 8 Vertical Slice Architecture 6 Domain-Driven Design 12 CQRS and Event Sourcing 10 Messaging and Event-Driven Architecture 9 Microservices 10

2 posts found #sequence-diagram

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Software Design PART 09

Sequence Diagrams 2: alt, opt, loop, par, break and ref for Error Paths and Async Flows

Combined fragments add conditions (alt, opt), early exit (break), repetition (loop), parallelism (par) and indivisibility (critical) to a sequence diagram, while ref calls another diagram; an asynchronous message has an open arrowhead and stays asynchronous even when awaited if the sender does not wait for the result. The post draws the HR Portal approval flow, the insufficient balance error and the e-mail and calendar entry sent through a queue from the real code.

7 Nov 2026 12 min 6

Software Design PART 08

Sequence Diagrams 1: Lifelines, Message Types, Activation and the Journey of an API Request

A sequence diagram shows the messages between participants in one scenario in time order: lifelines side by side, time flowing down, synchronous calls with filled arrowheads and replies with dashed lines. The post draws the HR Portal's POST /leave-requests request from Angular to SQL Server from the real code and EF Core log, and gives it as Mermaid code too.

7 Nov 2026 9 min 5