Serhat Ozgel, Developer in London, United Kingdom
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Serhat Ozgel

Verified Expert  in Engineering

Software Developer

London, United Kingdom
Toptal Member Since
April 28, 2020

Serhat is a software developer with over a decade of experience. His primary expertise is in building highly scalable web applications and architecting systems that can handle extremely high loads along with complicated business scenarios. The technologies he's most experienced with are the .NET platform, C#, and Azure but he can also competently code in Node.js.


Azure Functions, GRID, Azure Search, Azure Cosmos DB, Azure, ASP.NET Web API...
MongoDB, Elasticsearch, Redis, .NET, C#.NET, APIs, API Integration, REST APIs...
Let Me Test
Amazon Web Services (AWS), Node.js, APIs, REST APIs, Databases




Preferred Environment

Azure, Visual Studio

The most amazing...

...project I've been working on is to architect and develop a true microservice architecture for the leading app-commerce provider in the UK.

Work Experience

.NET Back-end Software Development

2017 - 2021
  • Architected and developed a microservice back end for the catalog and the checkout functionalities of the app-commerce platform.
  • Built the back-end SDK and worked across DevOps and product teams to enable the externalization of the platform.
  • Improved the back-end development culture by creating and leading back-end development and release processes, practices, documentation, and culture.
  • Improved the scalability of the maintainability of the platform, making it possible to scale to many more customers.
Technologies: Azure Functions, GRID, Azure Search, Azure Cosmos DB, Azure, ASP.NET Web API, .NET Core, C#, C#.NET, APIs, API Integration, REST APIs, ASP.NET, Databases

Full-stack Developer

2015 - 2016
  • Rearchitected the solution to empower millions of requests per minute, each calculating personalized recommendations in real-time without depending on the cache.
  • Built data storage strategies for MongoDB and Elasticsearch and optimized their servers to be able to serve millions of requests per minute. These systems were backing personalized recommendations for some of the biggest eCommerce platforms.
  • Improved the recommendation quality of the machine learning algorithm.
Technologies: MongoDB, Elasticsearch, Redis, .NET, C#.NET, APIs, API Integration, REST APIs, ASP.NET, Databases


2014 - 2014
Let Me Test
  • Developed an entire testing marketplace from scratch and launched as a SaaS product.
  • Built tools to record screens, capture the voice of testers, upload videos to AWS S3, and make available to clients through the testing platform.
  • Worked as a solo developer so I did everything from coding to sales to making the project successful.
Technologies: Amazon Web Services (AWS), Node.js, APIs, REST APIs, Databases

IT New Projects Manager

2013 - 2014
  • Oversaw the re-platforming process of the largest social network in Turkey.
  • Heavily optimized and recoded the systems to enable thousands of online users to interact online at the same time.
  • Served as the technical project manager and helped my team to move the entire platform from on-premise to Amazon Web Services.
Technologies: Amazon Web Services (AWS), Redis, MongoDB, .NET, C#.NET, APIs, API Integration, REST APIs, ASP.NET, Databases

Software Development Team Leader

2012 - 2012
  • Developed applications for both iOS and Android platforms.
  • Built and supported a native Android application for Liv Hospital: one of Turkey's most prestigious medical facilities.
  • Laid out technical foundations of the startup by setting up code repositories, accounts, and setting up automation.
Technologies: Java, APIs, API Integration, REST APIs, Databases

Senior Analyst Developer

2009 - 2012
  • Architected a major migration of the flagship product of the company from .NET Web Forms to .NET MVC.
  • Created solutions for the project to run partially on .NET Web Forms, partially on .NET MVC at the same time to enable the migration and a smooth transition.
  • Implemented major parts of the content management system (such as product management) that served over 200 websites worldwide.
Technologies: Microsoft SQL Server, .NET, C#.NET, Databases

Software Development Engineer

2007 - 2009
  • Built a desktop application for kiosks with plug-in support, which made it possible for developers to develop plug-ins to the desktop application.
  • Implemented isolation to provide plug-ins with hardware interaction and network access capabilities. Developers were able to write plugins either in C# or just HTML and JavaScript.
  • Built back-end services to enable large numbers of kiosks to be managed by a central system.
Technologies: Windows Forms (WinForms), .NET, C#, C#.NET, ASP.NET, Databases

Software Engineer

2006 - 2007
  • Implemented built-in search and scheduling mechanisms for the company's project management software.
  • Built a media management system for General Motors. The project allowed General Motors and its vendors to manage advertisement projects.
  • Designed and implemented a complex, customizable approval cycle.
  • Implemented, as a solo developer, a social network for photographers from scratch, took it live, and also supported it.
Technologies: ASP.NET Web Forms, C#.NET, ASP.NET, Databases

Product Search Microservice

An event-driven microservice where products are received as event data via Azure Event Grid, captured by Azure Functions, and saved to Azure Search. A .NET Core Search Web API then makes these products available for mobile apps. I designed and implemented this truly independent microservice which empowers 45+ native iOS and Android apps.

Let Me Test

Let Me Test was a SaaS platform for software developers to get their products tested by users. Users used a screen recording tool to record and upload their tests. The tests were made available to the software developers.
This was my own project and entirely built from scratch by me including screen recording, video automation, and the marketplace.

It was built using Node.js, AWS on the server-side. The web front end was built with AngularJS and the recording client was a .NET desktop application.

I had to abandon the project due to financial reasons.


Glint is a social networking platform that facilitates social interactions by playing games. This was a startup that I started with my friend. I built the back end of the project using Node.js and hosted it on AWS. It allowed users to play games either in real-time or asynchronously. From scratch, we built the front end and the back and of all the games, search, messaging, and user profiles.

Siberalem Cloud Migration is the #1 dating platform in Turkey. When I joined the project, it was run on-premise and struggling to scale. As the technical project manager, my team re-architected the project to run entirely on Amazon Web Services and we gradually moved everything to cloud. I wrote the back-end code and designed messaging and profile architecture to scale in the cloud.

Reloadly Node.js SDK
A Node.js SDK port of Reloadly Java APIs. The code has not been made public yet.

The SDK includes three libraries: Core, Authentication, and Airtime.
• Core provides reusable service classes, common DTOs, and utilities. • Authentication provides services to perform OAuth2 authorization.
• Airtime provides all services to interact with Reloadly APIs.
2002 - 2007

Bachelor's Degree in Computer Science Engineering

Dokuz Eylul University - İzmir, Turkey


Machine Learning



REST APIs, Node.js, Windows Forms (WinForms)


Azure Search, Visual Studio, Mocha




Azure Functions, Azure, Amazon Web Services (AWS)


C#.NET, C#, Java, ECMAScript (ES6), TypeScript


Databases, Azure Cosmos DB, MongoDB, Redis, Microsoft SQL Server, SQL Server DBA, Elasticsearch, Amazon S3 (AWS S3)


API Integration, APIs, GRID, ES6 Promises

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