Fatih Işık

Profile

My passion for technology is the driving force behind my continuous growth in the software industry. With a strong foundation in Computer Engineering and ongoing studies in Management Information Systems, I have developed my expertise over more than a decade, specialising in .NET and web technologies. As a leader, I prioritise teamwork and strategic decision-making, successfully managing projects from inception to completion. I am committed to building strong teams and delivering innovative solutions, always eager to learn and adapt in a fast-evolving field.

Software Engineering Manager / Defacto Technology

Jul 2023 - Current

We develop mobile and web cash register applications, where I contribute both as a developer and as the technical lead. I take responsibility for most of the R&D initiatives, guiding the team in exploring and implementing new technologies to keep the system modern, reliable, and scalable. Our stack includes .NET 6.0, .NET 7.0, .NET 8.0, Go, SQL Server, Couchbase, Elasticsearch, Flutter, Vue.js, Microservices, Dapr, and Nats. Over time, we extended the project with an offline mode using .NET 8 and SQLite. By leveraging SQLite’s JSON support, we achieved a more flexible, NoSQL-like data structure that increased adaptability and improved overall system design.

For disaster scenarios where connection to the central server is lost and sales backup cannot be performed, instead of installing a local central server in the store, we implemented peer-to-peer (P2P) communication between cash registers using gRPC. This allows sales data from one register to be shared with others, increasing system resilience and availability.

In the next phase of POS integration, the application dynamically presented installment options on the screen based on the card and bank agreements, enabling the selection of the most suitable installment plan for both the company and the customer. For example, if a card from a bank with a 'installment at cash price' agreement was used, the system prevented deferred sales, ensuring compliance with business rules and maximizing benefits for all parties.

Senior Developer / Defacto Technology

Apr 2021 - Jun 2023

As a Senior Developer, I contributed to the development of mobile and web cash register applications, focusing on both backend and frontend solutions. I was responsible for implementing new features, optimizing performance, and ensuring code quality through best practices and code reviews. The technology stack included .NET 6.0/7.0/8.0, Go, SQL Server, Couchbase, Elasticsearch, Flutter, Vue.js, Microservices, Dapr, and Nats. I actively participated in architectural decisions and collaborated with cross-functional teams to deliver scalable and maintainable solutions.

During this period, we integrated physical POS devices into the cash register system using Worldline (formerly Ingenico) terminals and the company's ECR protocol, IMPPro. The initial phase of the integration focused on payment redirection, allowing the cashier to continue operations directly on the POS device after initiating the transaction from the application.

.NET And Web Developer / 0ve1 I.T.

Dec 2015 - Mar 2021

In this role, I developed tourism and booking web projects, focusing on both backend and frontend development. My responsibilities included designing and implementing booking forms, integrating third-party APIs, and maintaining legacy systems. I utilized ASP.NET Web Forms, WCF for service-oriented architecture, and modernized user interfaces with jQuery and Bootstrap. I also ensured responsive design and cross-browser compatibility using HTML, CSS, JavaScript, and Bootstrap.

.NET And Web Developer And Server Administrator / YS Group

Aug 2014 - Jun 2015

As a Full Stack Developer and Server Administrator, I led the development of ad and e-commerce systems. My work involved building scalable web applications using ASP.NET MVC and Entity Framework for robust data management. I implemented dynamic user interfaces with Angular.js and jQuery, and ensured modern design with Bootstrap. Additionally, I managed Windows Server environments, including IIS and DNS Server configuration, deployment automation, and system monitoring for high availability.

.Net And Web Developer / Freelance or Hobby

May 2006 - Current

As a freelance developer and technology enthusiast, I continuously explore and learn new programming languages, frameworks, and tools. Since starting web development in 2006 with HTML and Classic ASP, I have applied my knowledge to a variety of personal and freelance projects. My focus is on building testable, maintainable, and scalable solutions, often experimenting with modern architectures and integrating new technologies into my workflow. Below are some of my completed projects, each designed to be fully functional and available for testing.

• Yeşilköy Köyü Web Sitesi - Live

  Front-End Development : HTML, CSS, JavaScript, jQuery
  Back-End Development : C#, ASP.NET Core, Entity Framework Core, PostgreSQL

• fiQuiz - Source Code - Quiz

  Front-End Development : HTML, SCSS, CSS, JavaScript, jQuery, Bootstrap, React
  Back-End Development : C#, ASP.NET Core, Entity Framework Core, MySQL

• SatcoDX Editor - Live - Source Code

  Front-End Development : HTML, SCSS, CSS, JavaScript, Bootstrap, Vue.js, BootstrapVue

Azerbaijan Technical University / Computer Engineering

2009 - 2014

Bachelor Degree

Osmancık High School

2002 - 2006

High School Degree