Software Developer · Java / Spring Boot · Web3 & backend · Computer Engineering @ MCÜ
İzmir, Türkiye · Open to internships and junior software roles
I ship products that people can actually use: backends, wallets, payments, and smart contracts.
At OverBlock I went from intern to software developer. I have worked on a live Web3 product with 40K+ users, published an npm package, launched a Sui mainnet app, and built invoice/payment flows on Stellar. CrossQuery is my Java 21 / Spring Boot work: a multi-model ideation panel with tests and CI.
const cem = {
role: "Software Developer",
company: "OverBlock",
study: "B.Sc. Computer Engineering · MCÜ",
ships: ["Java", "Spring Boot", "TypeScript", "PostgreSQL"],
chains: ["Stellar", "Sui / Move", "EVM / Solidity"],
proof: ["40K+ users", "npm: mantle-402", "Sui mainnet", "CrossQuery"],
};| Project | What I built | Stack |
|---|---|---|
| CrossQuery | Multi-model ideation panel: research, cross-examine, vote, scored Top-3. Tests + CI. | Java 21 · Spring Boot · JPA · Flyway |
| Quittance | Invoice → pay on Stellar → verify on Horizon → download payment proof | TypeScript · Next.js · Stellar |
| mantle-402 | HTTP 402 payment flow on Mantle, published as an npm package | TypeScript · EVM |
| Somiverse | Smart contracts + production fixes on a live platform with 40K+ users; PWA for mobile | Web3 · React · PWA |
| Mapmark | Location bookmarking on Sui, shipped to mainnet (mapmark.fun) | Move · TypeScript · React |
| order-system | Real-time restaurant order tracking, end-to-end | TypeScript · PostgreSQL |
More
- Argus: real-time token security analysis for AI agents
- WriteBlock: on-chain content on Sui (Move)
- NFTMarketPlace: mint / buy / sell (Solidity)
- bountylane: multi-agent task assignment
- MovieManegament: Java + data structures (course foundation)
Java / backend: Java 21 · Spring Boot · JPA · Flyway · REST · PostgreSQL · Docker
Also ships: TypeScript · Node.js · React · Next.js
On-chain: Solidity · Move · Stellar / Horizon · Freighter · EVM
- Software Developer @ OverBlock (İzmir)
- B.Sc. Computer Engineering @ Manisa Celal Bayar University
- Dept. Student Representative
- Building payment, identity, and agent tooling across Stellar / Sui / EVM