Mert Köse | A Developer Sketches
Writing about tech changes and my own opinions on them.
Blog
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Recently, I released a website, ogzkritik.com for the readers of the gaming magazine Oyungezer, which I contribute to as a writer. It’s basically a dashboard that indexes articles/reviews so you can easily find the issue number, score and author of the article you are looking for. Also, there are some fun stats with easy-to-use filters to mess with. Oyungezer has released the whole archive digitally but the ones until 2025 are available for free. OGZ Kritik takes an advantage of that so simply clicking the card will take you to exact issue that has the article you clicked on.
This site had existed way before, about 10 years ago I believe. The idea is not new but after seeing Claude improved itself massively, I decided to reawake the site because
- It didn’t look like a big Project
- I wanted to try how leaning on AI plays out in a real-world project
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My new project in adesso Turkey uses Kotlin in some services. It is the first time that I am using Kotlin and not gonna lie, I liked it so far. It gives you the feeling that this language is modern and has nice approaches to some problems. And that got me thinking about these solutions, why Kotlin decided that and such. And interesting enough that Kotlin doesn’t use some features Java has eg. checked exceptions. So I decided to break down these features to understand the general mindset behind Kotlin (and also Java)
One of the biggest advantages of Kotlin is that it can be used as both functional and object oriented. While that might raise a question to Java developers in that they are used to build a hierarchy no matter what they are writing, I think this flexible approach is better even for OOP approached apps. Why do we create a class for utilization methods anyway? Zipping everything inside a class, especially if you care about S (Single responsibility) from SOLID principle, results in lots of files, which make things harder to follow.
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Ah yes, a hot topic: AI. But how can I not write anything about a thing that will change billions of people’s life? And while so many people still think they are just another tool? NO they are not. In it’s second year, ChatGPT published its 5th version of its GPT algorithm with GPT-4o and every version puts something into its predecessor. Even Gordon Moore didn’t estimate this kind of speed in that even this article will be outdated just after several months.
Thinking and making assumptions about what kind of future awaits us is not easy obviously but I want to point out my concerns about my job (some other jobs too) to proactively decide what we can do to adapt it.
Work Experience
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Jan 2021 to now
adesso Turkey
Senior Java Developer, remote
Consulting on German projects for BMW, EnBW and Otto, in international teams that work in English.
Highlights
- Delivered two global BMW projects, used in 20+ countries, from architecture to deployment, with monitoring and operational reliability built in.
- Worked on a high-volume e-commerce platform that standardised product data for downstream systems across a 50M+ product catalogue.
- Migrated Kafka topics carrying 3.5 million records a day from AWS MSK to customer managed clusters.
- Moved 50+ database tables from on-premise Oracle to AWS PostgreSQL.
- Upgraded large microservices to Spring Boot 3 with asynchronous Kotlin and Java.
- Wrote Java 21 with 80%+ unit test coverage.
- Defined implementation-ready technical specifications that made AI-assisted development with GitHub Copilot and Claude Code efficient.
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Jul 2018 to Jan 2021
Innova
Software Specialist, Ankara
Backend services and a React frontend for telecom clients, at an IT solutions provider in the Türk Telekom Group.
Highlights
- Built login mechanisms for highly scalable apps serving over 2 million daily users.
- Designed RabbitMQ-based data traffic to support a microservice architecture.
- Worked with PostgreSQL, Oracle and MongoDB databases holding over 8 million records.
- Rebuilt the application frontend with React, Next.js and TypeScript.
Side Projects
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Deneysiz
A mobile app and backend for the No-To-Test charity, so people can check whether a brand tests on animals. I built the backend, the admin panel and the AWS infrastructure.
Spring Boot, JWT, Hibernate, PostgreSQL, AWS
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OGZ Kritik
A dashboard for readers of Oyungezer magazine, with article and editor stats and Steam API visuals. I wrote about what building it with AI taught me.
Angular 21, AWS Amplify, Lambda, CloudFront, Route 53, S3
About me
Despite everything bad going on, there is still joy of learning and sharing. I will always pursue that and this site is a reflection of that.
- Work
- Senior Java Developer, with over 8 years in the industry.
- Education
- BSc in Computer Engineering, Ankara University, 2018.
- Writing
- Freelance editor at Oyungezer, a Turkish gaming magazine, and the writer of this blog.
- Volunteer
- Volunteer developer for the No-To-Test charity, and volunteer at Make-A-Wish Türkiye.
- Outside work
- Travel, movies and playing all kinds of guitar.
What I work with
- Backend
- Java, Kotlin, Spring Boot, Spring Cloud, Hibernate, Project Reactor
- Data and messaging
- PostgreSQL, Oracle, MongoDB, Apache Kafka, RabbitMQ, Elasticsearch
- Cloud and delivery
- AWS (Lambda, ECS, S3, SQS, RDS, DynamoDB), Docker, Kubernetes, Jenkins, GitHub Actions
- Frontend
- Angular, React, TypeScript, CSS
- With AI
- GitHub Copilot, Claude Code, OpenCode
- Certificate
- AWS Certified Developer, Associate.
Contact at any time
Feel free to ping me anywhere! Twitter is mostly for gaming, YouTube is for music, LinkedIn and GitHub are, well, coding and business.