Yusuf Yilmaz

Senior Fullstack Engineer

About Me

A Brief Introduction to My Background and Interests

In 2012, I started my journey in software development, driven by a passion for building practical, user-focused applications. Over the years, I’ve worked across industries like telecom, IT, and startups, tackling real-world challenges. One highlight was at Turkcell, where I developed a React-based WebChat app and multichannel chat gateway that handled over 600,000 customer interactions daily. That experience taught me a lot about creating scalable, reliable systems that perform well under high traffic.

I’ve also created tools for automating Google Ads management, a Slack messaging system for cross-team communication, and an ETL composer for processing SEM alerts data in BigQuery when i work at Toptal. More recently, I worked on an AI-powered success story generator that personalizes talent stories, combining AI with a user-friendly interface to make content creation faster and more impactful. These projects reflect my focus on efficiency, scalability, and finding solutions that fit real needs.

This portfolio app is something I’m proud to share. It showcases my work using Next.js, React, Node.js, TypeScript, and Tailwind CSS, along with NLP-based classification to enhance the ChatGPT-powered bot, making it more responsive in answering questions about my skills and experience. You can explore my projects, learn about my background, and even leave a referral or feedback through the app’s referral bot. Every part of this app, from the UI to the backend, represents my hands-on approach and dedication to building practical, well-rounded applications.

Outside of work, I’m always exploring the latest tech trends, hitting the gym, or spending time with friends, ready to take on new challenges and ideas.

View my Resume

Professional Experience

A Summary of My Roles, Companies, and Projects

  1. Oct 2021 - Oct 2024

    Toptal

    Senior Fullstack Engineer

    • Developed the Assets Generator using Next.js to automate interviews and create success stories via AI, generating personalized success stories with an interface for modifying, fixing, and publishing stories.
    • Created 8 tools for automating Google Ads management, including positive/negative keyword generation, asset reviews, and dynamic content management from scratch by getting parts in all phases, Planning, Design, Development, Testing, Deployment.
    • Migrated around 10 legacy websites (e.g., JavaScript Minifier, Html shell, Hastebin, css3maker) to Next.js, improving performance and responsiveness and design.
    • Created centralized Slack service for handling Slack messages across multiple applications. This system streamlined communication processes by managing message requests in one place, improving efficiency and reducing complexity for users interacting with multiple platforms.
    • Created an ETL composer to save BigQuery Google ads data into usable data for the SEM alerts system.
    • Mentoring Junior team members

  2. Oct 2020 - Sep 2021

    Scopely

    Senior Software Engineer

    • Development for frontend and backend for Web automation tool that is used by game engineers to create mobile device tests on amazon device farm and see results and reports according to these tests.
    • Development for Unity part of the project.
    • Converted the automation tool to micro frontend architecture.

  3. Oct 2019 - Sep 2020

    Marfeel

    Senior Frontend Engineer

    • Converted existing web products to React and created CLI tools for media providers.
    • Developed automatic, generated Playgrounds for providers. Implemented Server-Side Rendering (SSR) for React components.

  4. Apr 2015 - Oct 2019

    Turkcell

    Senior Software Engineer

    • Led the development of WebChat, Chat Gateway, Bot Info, Integration service, Chat and Phonex Configuration Manager, Transaction Manager, Opera, Phonex, IWS and other customer service tools for Turkcell, handling over 600,000 daily interactions.
    • Converted WebChat to React and Redux within two weeks, significantly improving scalability.
    • Designed and implemented a multichannel chat gateway, integrating over 20 clients into a unified architecture.
    • Mentoring Junior team members
    • Teaching and leading for chat platform to team members and infrastructure teams.

  5. Nov 2012 - Apr 2015

    SESTEK

    Software Engineer

    • Developed core components for text-to-speech (TTS) and speech recognition (SR) systems.
    • Designed and implemented web services using C++, C#, WCF, and built mobile applications with Swift and Objective-C.

Projects & Contributions

A showcase of the notable projects I have worked on, including open-source tools and client-based work.

  • Automated Story Generator

    Senior Fullstack Engineer

    A tool designed to automate the generation of customized success stories by utilizing AI to process user input and generate personalized narratives. I was responsible for the full-stack development, handling both frontend (React, Next.js) and backend (Node.js, Prisma, PostgreSQL) components, along with implementing the queue system for processing requests using bullMQ and Redis.
    React
    Next.js
    Prisma
    Node.js
    PostgreSQL
    AI
    Dify.AI
    BullMQ
    Redis
    Google Cloud
    Kubernetes
    Project and all rights reserved by TOPTAL

  • Content Monitoring Tool

    Senior Fullstack Engineer

    A system for monitoring public content and generating alerts based on specific conditions. Integrated with a task management system to create tickets for any issues found. I was involved in full-stack development, ensuring proper data flow from the frontend to the backend while working with APIs for content analysis and task management.
    Kubernetes
    React
    TypeScript
    SCSS
    Prisma
    Node.js
    PostgreSQL
    BullMQ
    Redis
    Project and all rights reserved by TOPTAL

  • Negative Keyword Generation Tool

    Senior Fullstack Engineer

    A tool that automates the generation of negative keywords for advertising campaigns, improving SEO performance. I was responsible for full-stack development, creating a user-friendly frontend with React and integrating with Google Ads API to dynamically generate keywords and manage campaigns.
    Kubernetes
    React
    Next.js
    TypeScript
    Prisma
    PostgreSQL
    Node.js
    Google Ads API
    Google Cloud
    BullMQ
    Redis
    Project and all rights reserved by TOPTAL

  • Performance Alerts System

    Senior Fullstack Engineer

    An automated system designed to manage and update dynamic content on various web pages. I was responsible for the full-stack development, including integrating with content APIs, creating a responsive frontend, and building the backend for processing content updates in real time using Kafka.js and Redis.
    Kubernetes
    React
    Next.js
    TypeScript
    Prisma
    PostgreSQL
    BigQuery
    Google Cloud
    ETL
    Node.js
    Project and all rights reserved by TOPTAL

  • Positive Keyword Optimization Tool

    Frontend Developer

    A tool for automating the generation and optimization of positive keywords for advertising campaigns. I contributed to the frontend development, focusing on creating a responsive UI and integrating it with backend services that interact with the Google Ads API for seamless campaign management.
    Kubernetes
    React
    Next.js
    Node.js
    TypeScript
    Prisma
    PostgreSQL
    Google Ads API
    Google Cloud
    BullMQ
    Redis
    Project and all rights reserved by TOPTAL

  • Dynamic Content Management System

    Senior Fullstack Engineer

    An automated system designed to manage and update dynamic content on various web pages. I was responsible for the full-stack development, including integrating with content APIs, creating a responsive frontend, and building the backend for processing content updates in real time using Kafka.js and Redis.
    Kubernetes
    React
    Next.js
    Google Cloud
    TypeScript
    Prisma
    PostgreSQL
    Node.js
    Kafka.js
    BullMQ
    Redis
    Project and all rights reserved by TOPTAL

  • Media Assets Review Tool

    Senior Fullstack Engineer

    A tool for reviewing and managing media assets used in marketing campaigns. My role involved full-stack development, including building the frontend for asset review and management, as well as developing the backend integration with the advertising API and media storage.
    Kubernetes
    React
    TypeScript
    Next.js
    Prisma
    PostgreSQL
    Google Ads API
    Google Cloud
    Redis
    Node.js
    Project and all rights reserved by TOPTAL
  • CSS3 Maker project image

    CSS3 Maker

    Senior Frontend Developer

    A public tool designed to simplify the creation of CSS3 styles, providing a range of customizations and previews for web developers. With CSS3 Maker, users can generate CSS code for various effects, such as gradients, transforms, transitions, and animations, helping streamline development workflows and enhance styling options with minimal effort.
    React
    TypeScript
    Next.js
    SCSS
    Project and all rights reserved by TOPTAL
  • JavaScript Minifier project image

    JavaScript Minifier

    Senior Frontend Developer

    A public tool for minifying JavaScript code, used by developers to compress and optimize their scripts. I developed the frontend interface using React and Next.js, ensuring a simple and intuitive user experience.
    React
    TypeScript
    Next.js
    SCSS
    Redis
    Project and all rights reserved by TOPTAL
  • HTMLShell project image

    HTMLShell

    Senior Frontend Developer

    A public tool that generates HTML code snippets. I developed the frontend using React and Next.js, ensuring a user-friendly experience for developers needing to generate HTML quickly.
    React
    TypeScript
    Next.js
    SCSS
    Redis
    Project and all rights reserved by TOPTAL
  • Keycode Tool project image

    Keycode Tool

    Senior Frontend Developer

    A public tool for developers to test and find keycodes for keyboard events. I built the frontend using React and Next.js, providing an easy-to-use interface for testing keycodes.
    React
    TypeScript
    Next.js
    SCSS
    Redis
    Project and all rights reserved by TOPTAL
  • Hastebin project image

    Hastebin

    Senior Full Stack Developer

    A public tool for sharing code snippets. I contributed to the full-stack development, focusing on building a responsive frontend with React and Next.js and ensuring proper backend integration for storing and retrieving code snippets.
    React
    TypeScript
    Next.js
    SCSS
    Node.js
    Redis
    Project and all rights reserved by TOPTAL
  • CSS Minifier project image

    CSS Minifier

    Senior Frontend Developer

    A public tool for minifying CSS code, helping developers compress and optimize stylesheets. I worked on the frontend using React and Next.js to ensure smooth functionality and user-friendly interaction.
    React
    TypeScript
    Next.js
    SCSS
    Redis
    Project and all rights reserved by TOPTAL
  • HTML Minifier project image

    HTML Minifier

    Senior Frontend Developer

    A public tool for minifying HTML code, used to compress HTML files for improved performance. I was responsible for building the frontend using React and Next.js.
    React
    TypeScript
    Next.js
    SCSS
    Redis
    Project and all rights reserved by TOPTAL

  • Automation Tools for Engineering Teams

    Senior Software Engineer

    Developed automation tools for engineering teams to streamline frontend and backend development processes.
    React
    TypeScript
    Node.js
    Redis
    .NET Core
    .NET
    C#
    NUnit
    Project and all rights reserved by SCOPELY

  • Web Product Migration to Modern Framework

    Senior Full Stack Developer

    Led the conversion of existing web products to a modern framework, improving performance and maintainability.
    React
    SCSS
    CSS
    HTML5
    JavaScript
    TypeScript
    Project and all rights reserved by MARFEEL

  • WebChat

    Senior Software Engineer

    Developed a real-time WebChat platform for Turkcell for customers to talk customer service, supporting high traffic.
    React
    Node.js
    Websocket
    Redux
    REST API
    CSS
    HTML5
    Project and all rights reserved by TURKCELL

  • Chat Gateway

    Senior Software Engineer

    Designed and implemented a multi-channel chat gateway for customer services chat platforms.
    .NET
    REST API
    Websocket
    C#
    MSSSQL
    Entity Framework
    Genesys Framework
    Unity Framework
    Bot Framework
    Project and all rights reserved by TURKCELL

  • Text-to-Speech Features

    Software Engineer

    Developed key features for a text-to-speech system, integrating with multiple platforms.
    C#
    C++
    Objective-C
    Project and all rights reserved by SESTEK

  • Speech Recognition Features

    Software Engineer

    Worked on developing speech recognition features aimed at enhancing customer interactions.
    C#
    C++
    Objective-C
    Project and all rights reserved by SESTEK

  • Yusuf`s Devhub Showcase

    Fullstack Engineer

    DevHub Showcase is a comprehensive portfolio platform designed to present your professional journey, skills, and projects. It highlights your technical expertise across frontend, backend, database, and data pipeline skills while showcasing detailed experience in modern frameworks like React, Next.js, and Node.js, as well as cloud services, DevOps tools, and testing practices. Visitors can interact through built-in chat features to ask questions or leave referrals, allowing for an engaging and interactive experience that provides insights into your work and accomplishments.
    React
    Next.js
    TypeScript
    Node.js
    Prisma
    PostgreSQL
    Tailwind CSS
    Docker
    Redis
    AWS
    CSS
    Project and all rights reserved by SESTEK

Skills

A Summary of My Technical Skills and Proficiency

  • Frontend

    JavaScript (8+ yrs)
    React (8+ yrs)
    Next.js (6+ yrs)
    TypeScript (6+ yrs)
    Redux (4+ yrs)
    Redux Saga (2+ yrs)
    Context API (6+ yrs)
    HTML5 (8+ yrs)
    CSS (8+ yrs)
    SCSS (6+ yrs)
    React Native (1+ yrs)
    Tailwind CSS (2+ yrs)

  • Backend

    Node.js (6+ yrs)
    Express.js (6+ yrs)
    .NET (6+ yrs)
    .NET Core (6+ yrs)
    C# (6+ yrs)
    Python (2+ yrs)
    Java (2+ yrs)
    Unity Framework (1+ yrs)
    Objective-C (1+ yrs)
    Swift (2+ yrs)
    C++ (2+ yrs)

  • Orm

    Prisma (4+ yrs)
    Entity Framework (2+ yrs)

  • Database

    Redis (4+ yrs)
    MySQL (2+ yrs)
    PostgreSQL (4+ yrs)
    MSSSQL (4+ yrs)
    MongoDB (1+ yrs)

  • Queue

    BullMQ (3+ yrs)

  • Api

    Google Ads API (2+ yrs)
    Websocket (2+ yrs)
    REST API (6+ yrs)
    SOA (2+ yrs)
    Genesys Framework (1+ yrs)
    Bot Framework (1+ yrs)

  • Cloud

    BigQuery (2+ yrs)
    Docker (3+ yrs)
    AWS (2+ yrs)
    Google Cloud (4+ yrs)
    Kubernetes (3+ yrs)

  • Data pipeline

    Kafka.js (3+ yrs)
    ETL (2+ yrs)

  • Web service

    REST (10+ yrs)
    SOAP (4+ yrs)

  • Test

    Jest (6+ yrs)
    Mocha (2+ yrs)
    Cypress (3+ yrs)
    Playwright (3+ yrs)
    NUnit (1+ yrs)

  • Platform

    GitHub (4+ yrs)

  • Ai

    AI (2+ yrs)
    Dify.AI (2+ yrs)
    ChatGPT (2+ yrs)

Education & Credentials

Academic Background and Achievements

  1. Jun 2018 -

    Ozyegin University

    PhD in Computer Science and Artificial Intelligence

    Focused on advanced topics in Artificial Intelligence, Machine Learning, and Computational Science, with research in predictive models and AI-driven solutions.

  2. Sep 2013 - Jun 2016

    Boğaziçi University

    Master of Science in Software Engineering

    Focused on software engineering principles, including software design, architecture, and development.

  3. Sep 2007 - Jun 2012

    Istanbul Technical University

    Bachelor of Science in Control and Computer Engineering

    Specialized in computer engineering and control systems.

Testimonials & Referrals

Read feedback and testimonials from colleagues and clients about my work and collaborative efforts.

  • “I had the pleasure of working with Yusuf at Toptal, where he made a significant impact as a Senior Full-Stack Engineer. He is an incredibly fast developer, consistently delivering results with impressive speed and precision. Yusuf was always proactive in creating solutions, and bringing ideas to the table. His execution was top-notch, ensuring that his innovative concepts were implemented effectively.
    “Yusuf would be a fantastic asset to any team, combining speed, proactivity, and a collaborative spirit to deliver exceptional results.

    Marcelo Carneiro

    Toptal, Team manager