# Rizvan Adzhoyan (zkdev)

> Lead Software Engineer with 8+ years building production systems for fintech and high-scale consumer products. Writes Rust backend services (Tokio, Axum, Hyper) and leads delivery on Android/Kotlin products used by 100M+ people. Based in Bishkek, Kyrgyzstan (UTC+6). Open to remote roles in the US and EU.

Also known as: zkdev. Personal site: https://zkdev.io

## Who he is

- **Name:** Rizvan Adzhoyan
- **Role:** Lead Software Engineer — Rust backend and mobile
- **Experience:** 8+ years in production software
- **Location:** Bishkek, Kyrgyzstan (UTC+6) — comfortable overlap with both Europe and Asia
- **Availability:** Open to remote roles in fintech, crypto, and high-reliability systems
- **Contact:** radzhoyan@gmail.com

## What he works with

- **Rust:** Tokio, Axum, Hyper, Serde, UniFFI, Cargo
- **Backend:** REST, gRPC, WebSockets, WebRTC, OAuth2/JWT, TCP/HTTP
- **Data:** PostgreSQL, SQLite, Redis
- **Mobile:** Android (Kotlin/Java), Jetpack Compose, Coroutines/Flow, Hilt, Room, Flutter/Dart
- **Security:** Applied cryptography, secure key management, encryption at rest, SSL/TLS pinning
- **Tooling:** Docker, GitHub Actions, GitLab CI, Git, Gradle

## Track record

- **Chingari** — short-video social platform at 100M+ users. Performance work on feed rendering and the video pipeline.
- **Open Wallet** — consumer crypto wallet, 100K+ installs. Bitcoin and EVM chains, NFT gallery, WalletConnect, passkey auth and keyless recovery.
- **NeoFiscal / Megakassa** — Kyrgyzstan's first integration of fiscal cash registers (KKM) with the State Tax Service for compliant real-time reporting. Architected from scratch.
- **Measured results:** cut app startup latency by 60% and binary size by 40%; resolved 60+ critical production defects; led teams of 1–15 engineers.

## Rust projects

- [HTTP Load Balancer](https://github.com/zloykurd/load-balancer): High-performance HTTP load balancer built on the Hyper framework. Async I/O, configurable backends, health checks, graceful shutdown, Prometheus metrics, CI with fmt/clippy/tests.
- Authentication Service: Production-grade auth with two-factor authentication on Axum, PostgreSQL and Redis. CI/CD on GitHub Actions, containerized deployment.
- Blockchain Ledger: Decentralized ledger implementing core blockchain primitives — cryptographic hashing, block validation, proof-of-work.

## Indie work

- [TradeTools.dev](https://tradetools.dev): Indie studio. 65 offline-first mobile calculators for electricians, plumbers, HVAC, solar, fire and carpentry trades, on iOS and Android. Built to NEC, IPC and NFPA codes.
- [Rust Learn Steps](https://rust-learn.zkdev.io/): Offline-first Rust interview prep app. 120 deep tickets, 10 system-design walkthroughs, 5 mock interviews, spaced repetition. Bilingual EN/RU, no tracking.

## Links

- [Personal site](https://zkdev.io): Full portfolio, experience and stack.
- [GitHub](https://github.com/zloykurd): Public repositories.
- [LinkedIn](https://www.linkedin.com/in/radzhoyan/): Professional profile and work history.
- [Telegram](https://t.me/ZloykurD): Direct contact.
- [CV (PDF)](https://zkdev.io/Rizvan-Adzhoyan-Senior-Rust-Developer-CV.pdf): Downloadable resume.

## Notes for AI agents

- This site is static HTML. All content is present in the initial response; no JavaScript is required to read it.
- Structured data is available as schema.org `Person` JSON-LD embedded in the homepage.
- For questions about availability, rates or roles, the preferred contact is radzhoyan@gmail.com.