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Software & AI Engineer

ArhanDönerkaya

I build software that ships, and AI agents you can trust.

Informatics @ CTU in Prague · SafeAgentDB · LLM evaluation

Arhan Dönerkaya, Software & AI Engineer
Open to internships and part-time roles in software and AI engineering.
Side A

Work

SafeAgentDB

Safe SQL writes for AI agents. Open source, on PyPI.

A Python library that runs an AI agent's SQL in a tenant-scoped in-memory sandbox, validates and diffs the changes, then applies them to production in one atomic transaction with compare-and-swap conflict detection.

432 automated tests, CI on Python 3.10 to 3.12 and PostgreSQL 16

  • Two-arm benchmark: 68 tasks, Claude agents, an independent auditor, and replay, uninformed and informed conditions.
  • On v0.3.1 it prevented every in-scope unsafe write that reached it, with zero false positives.
  • The benchmark exposed a key-collision bug that blocked valid inserts (9/99 safe tasks); fixed and verified in v0.3.1 (0/102).
  • Python
  • SQLAlchemy
  • Pydantic
  • PostgreSQL
  • SQLite
  • pytest
  • GitHub Actions

GATE

AI exam generator

Generates exam questions with LLMs and checks them with a second model (cross-model verification). LaTeX math, a custom exam builder and weak-area analytics.

  • Python
  • FastAPI
  • Next.js
  • PostgreSQL
  • Redis
  • Docker
  • OpenAI and Anthropic APIs

Cafly

QR menu and ordering SaaS for cafés

Real-time ordering over WebSockets, an LLM menu assistant, role-based access for owners and staff, and subscription billing.

  • Python
  • FastAPI
  • Next.js
  • PostgreSQL
  • Redis
  • Docker
  • Anthropic API
All projects
Side B

Creative

VOIDMar 2026 – presentInteractive browser experimentsNine experiments in dependency-free JavaScript (8,000+ lines): fluid and physics simulations, WebGL particle systems, Web Audio synthesis, a platformer and a simulated desktop OS.JavaScriptWebGLThree.jsWeb Audio APICanvas

Liner Notes

I'm a first-year Informatics student at the Czech Technical University in Prague, and I build software that ships.

As co-founder and CTO of SimplWallet (2025–2026), I built a non-custodial crypto wallet for Ethereum, Solana and Bitcoin that let people send crypto to a phone number, from the React Native app to the Firebase backend and key management.

I also wrote SafeAgentDB, an open-source Python library that lets AI agents write to multi-tenant databases safely: changes run in a sandbox, get validated and diffed, then sync atomically to production. I designed its benchmark with an independent auditor, and it found a real bug in my own library, which I then fixed.

Through Vibbe Studio I build and host products such as Cafly, an ordering platform for cafés, and GATE, an AI exam generator.

I'm focused on AI engineering and LLM evaluation, and I'm open to internships and part-time roles.

Multi-instrumentalist and live performer (guitar, bass, piano, drums, vocals).

Credits

  1. Nov 2025 – Feb 2026

    Co-Founder & CTO, SimplWallet Inc.

    Delaware, US, remote

    • Designed and built SimplWallet, a non-custodial multi-chain crypto wallet (Ethereum, Solana, Bitcoin) that let users send crypto to a phone number instead of a wallet address; took the product from zero to a beta-ready MVP.
    • Built the iOS and Android app in React Native, Expo and TypeScript: 25+ screens covering wallet creation and import, sending, token swaps, NFT gallery, a WalletConnect dApp browser and a DeFi dashboard.
    • Implemented key management with BIP39/BIP32 derivation per chain, AES-256-GCM encrypted seed storage in the device keychain, and biometric unlock.
    • Built the backend on Firebase: phone-number authentication, Firestore with client read-only security rules, and Cloud Functions (TypeScript, Node.js) for blockchain webhooks, push notifications and rate-limited phone-to-wallet linking.

    No link: the code is private and the product is not live.

  2. Jun 2025 – present

    Founder, Vibbe Studio

    • Run a small product studio that designs, builds and hosts web products, including Cafly, GATE and VOID.
    • Delivered websites for hospitality clients, including Özsüt İdealtepe and Jarden De La Rue.
    • Operate production infrastructure on two Hetzner Linux servers with Docker and Caddy.
  3. Sep 2026 – Jun 2029 (expected)

    Bachelor's degree in Informatics, Czech Technical University in Prague, Faculty of Information Technology

    Prague, Czechia

  4. Mar 2026

    CS50: Introduction to Computer Science, Harvard University

Instruments

Languages
Python · TypeScript · JavaScript · SQL
Backend and data
FastAPI · SQLAlchemy · Pydantic · PostgreSQL · Redis · Firebase · REST APIs · WebSockets
Frontend and mobile
React · Next.js · React Native · Expo
Infrastructure and testing
Docker · Caddy · Linux servers · Git · GitHub Actions · pytest
AI
LLM APIs (Anthropic, OpenAI, Gemini) · LLM evaluation and benchmark design · cross-model verification
Blockchain
ethers.js · Solana web3.js · BIP39/BIP32 HD wallets · WalletConnect
Spoken
Turkish (native) · English (fluent, IELTS 6.5)

Get in touch

Open to internships and part-time roles in software and AI engineering. The fastest way to reach me is email.

arhandonerkayaeu@gmail.com