About
About Me
I write Rust where it matters most — kernel modules, cryptographic pipelines, financial protocols. From Linux DCO drivers to on-chain AMMs.
Full stack of hard problems — kernel-space networking with C interop, high-load backend services in Axum, Actix-web and Rocket, Solana DeFi, ZK proof systems. 5 years of production Rust, from no_std to REST APIs.
I don’t reach for abstractions until I understand what’s underneath them. That’s why my systems are fast, my backends are boring (in a good way), and my smart contracts don’t get drained.
Beyond code: building keyboards, diving (SSI diving professional), lifting weights, and listening to way too much Meshuggah and Humanity’s Last Breath. Obsessed with factory and automation videogames.
What I’ve Built
Networking & Kernel
- OpenVPN DCO kernel module — Rust/C interop in Linux kernel (
no_std). Architected per-peer workqueue system replacing shared queues, improving throughput by 13.4% for millions of VPN users. Diagnosed and fixed production race conditions: TOCTOU double-free, NAPI cleanup race, conntrack refcount leaks, IPv6 routing loop. Contributed upstream fix merged into OpenVPN 2.6.20 (PR #945). (Vpnable) - DPI evasion & traffic obfuscation — Reverse-engineered Deep Packet Inspection fingerprinting vectors in a production transport proxy. Fixed TLS fingerprinting, protocol turn-taking violations, and statistical bias in random fields. Wire-level traffic analysis with tshark. (Vpnable)
- Per-user bandwidth throttling — Built from scratch: token bucket rate limiting in eBPF kernel-space with TC hooks, DCO-aware attachment for TUN vs physical NIC, 6 BPF maps for state tracking, full Rust userspace daemon with Aya framework. IPv4/IPv6 unified. (Vpnable)
- XDP firewall — Pure Rust eBPF firewall at NIC level. Per-IP rate limiting with token bucket, IPv4/IPv6 dual-stack, port-based filtering, runtime config via pinned maps. 25+ tests. (Personal)
Backend Systems
- Enterprise platform (4 services, 1,220+ commits) — Order management, billing, user/org management, Salesforce bidirectional sync (orders, leads, contacts, accounts). Found and fixed a leap year bug in license fee calculations that affected revenue. Restored a broken user invitation system by merging data across services with different schemas. Rust/Rocket/Axum, PostgreSQL, Docker. (NXLog)
- ZK proof verification pipeline — Migrated proof pipeline from RSA to X25519 SealedBox encryption. Async proof flow with webhook callbacks, WebSocket broadcasting, privacy budget tracking. Refactored entire backend: decomposed 15+ controllers into service layers, improved test coverage from 40% to 60%, uncovered critical authorization bugs. 258 commits in 2 months. (Provably)
- Automated trading system — TradingView webhook integration, multi-broker abstraction (Alpaca, ByBit), PostgreSQL/SQLx, async Tokio architecture, Docker. (Personal)
Blockchain & DeFi
- Solana DEX with AMM — Complete decentralized exchange from scratch. Custom constant product market maker (x*y=k), liquidity pools, fee collection, slippage protection. 841 lines of tests. No forked code. (Encode Club bootcamp)
- Token voting governance system — Solana Token-2022, dual program architecture, PDA-based state management, fee-based voting, automated token distribution, CLI tooling. (Nyoka)
- Cross-chain price oracle — Substrate pallet fetching prices from 5 DEXes across 4 EVM chains via direct smart contract calls (no API dependencies). Uniswap V3 sqrtPriceX96 math, offchain workers, unsigned transactions. (Personal)
Technical Expertise
Core Skills:
- Rust/C interop and FFI
- Kernel-space optimization
- Async runtime tuning (Tokio)
no_stdprogramming- Memory management & zero-copy patterns
- Idiomatic Rust patterns
Backend:
- Axum, Actix-web, Rocket
- PostgreSQL, Redis
- Docker, Kubernetes
- CI/CD pipelines
Blockchain:
- Solana (Anchor framework)
- Substrate/Polkadot
- Smart contract security
- DeFi protocol design
Work Experience
Provably — Rust Core Backend Engineer (Jan 2026 - Present)
- Refactored Rust/Axum backend architecture by decomposing controllers into service layers with unified error handling and authorization
- Built comprehensive test suite for core API modules, uncovering and fixing critical authorization bugs
- Designed and integrated new middleware system for zero-knowledge proof verification pipeline across customer data sources
Vpnable Limited — Rust Systems Engineer (Jul 2024 - Jan 2026)
- Architected per-peer workqueue system improving throughput by 13.4%
- Implemented kernel-space anti-censorship obfuscation with <0.1% overhead
Nyoka — Rust/Solana Blockchain Engineer (Oct 2024 - Sep 2025)
- Built token-based voting system for platform governance
- Architected smart contract infrastructure with PDAs
NXLog — Rust Core Backend Engineer (Dec 2022 - Jul 2024)
- Developed four key platform components using Rust
- Used Rocket and Axum for scalable web applications
Vpnable Limited — Rust Backend Engineer (Apr 2021 - Dec 2022)
- Optimized system performance by 30% through database
query optimization and efficient async operations. - Architected production backend services in
Rust (Actix Web, Diesel ORM, Tokio) for mobile applications.
Get in Touch
- CV: NikolaiShelekhov_Rust_Engineer_CV.pdf
- Email: [email protected]
- Telegram: @alloc33
- LinkedIn: linkedin.com/in/nshelehov
- GitHub: github.com/alloc33