# David Vennik

- **Email:** davidvennik@smesh.lol
- **Location:** Croatia (Remote)
- **Source:** [git.smesh.lol](https://git.smesh.lol/) | [github.com/mlekudev](https://github.com/mlekudev) | [github.com/l0k18](https://github.com/l0k18)
- **LinkedIn:** https://www.linkedin.com/in/david-vennik-9aa74a407/

## Summary

Senior backend and distributed systems engineer with 10+ years building production services in Go. Designed and deployed event-driven architectures, real-time streaming pipelines, and fault-tolerant distributed systems handling concurrent connections across geographically distributed node networks. Deep experience with event sourcing patterns, publish/subscribe messaging, cross-service synchronization, and horizontally scalable infrastructure.

Built protocol-level equivalents to centralized event streaming systems (Kafka, Pulsar) using peer-to-peer architectures - designing for reliability, idempotent processing, and durability without reliance on centralized message brokers. Production experience with containerized deployment, CI/CD automation, and bare-metal operations.

Combined with full-stack delivery capability: React/TypeScript frontends, comprehensive E2E test infrastructure, and AI-augmented development workflows.

## Skills

- **Languages:** Go (10 years), TypeScript, Rust (gRPC integration), SQL, Solidity
- **Backend & API:** gRPC/Protobuf, REST, WebSocket, GraphQL
- **Event Streaming & Messaging:** Event-driven architecture, event sourcing, publish/subscribe patterns, real-time message routing, append-only logs, cross-service event synchronization, CQRS
- **Distributed Systems:** Consensus protocols, gossip networks, peer-to-peer networking, relay infrastructure, horizontal scaling patterns, fault-tolerant service design, idempotent processing
- **Infrastructure & Ops:** Linux, Docker, containerized service deployment, CI/CD (GitHub Actions, GitLab CI), systemd, Caddy, bare-metal operations, system monitoring and observability (pprof, structured logging, performance profiling)
- **Databases & Storage:** PostgreSQL, Badger (embedded LSM key-value), append-only log stores, event-sourced data models, embedded databases, key-value stores
- **Concurrency:** CSP channel-based architecture, Actor model, SIMD optimization (AVX2), memory-efficient pipelines, zero-copy techniques
- **Frontend:** React 19, TypeScript, TanStack (Router/Query/Store/Form), Radix UI, Tailwind v4, Svelte
- **Testing:** Playwright E2E, integration testing, load testing, automated browser testing
- **AI Engineering:** Claude Code (custom skills, MCP servers, agentic workflows), AI-augmented architecture and code generation
- **Additional:** Cryptographic protocol implementation (secp256k1, Schnorr, ECDH, MuSig2), compiler tooling, LLVM

## Experience

### Senior Backend Engineer & Systems Architect
*Feb 2026 - Present*

Designed and operate distributed event streaming infrastructure for a live social platform. Built horizontally scalable relay network processing real-time messages across geographically distributed nodes, implementing pub/sub routing with idempotent delivery guarantees. Developed encrypted group messaging layer using MLS protocol with multi-relay event synchronization.

Key achievements:
- Designed event streaming pipeline equivalent to centralized message broker architectures (Kafka/Pulsar patterns) using peer-to-peer topology - eliminating single points of failure while maintaining ordered delivery and durability guarantees
- Built WASM-based client architecture with dedicated worker threads for cryptographic signing, network I/O, and state management
- Implemented cross-platform service deployment targeting Linux, macOS, and WebAssembly with Docker and systemd

Stack: Go, TypeScript, WebSocket, gRPC, WASM, Docker, Linux, systemd

### Full Stack Developer - Plebeian Market
*Sep 2025 - Mar 2026*

84 merged pull requests to production React 19/TypeScript decentralized marketplace. Implemented real-time event subscription system across distributed relay network with multi-endpoint progress feedback and retry logic for data migration. Built comprehensive Playwright E2E test suite covering authentication, payments, CRUD operations, and multi-user scenarios.

Stack: React 19, TypeScript, TanStack Router/Query v5, Radix UI, Tailwind v4, Playwright, Bun

### Senior Backend Engineer - Hubmaker Labs
*Oct 2023 - Jul 2025*

Built distributed relay infrastructure with RPC interface for federated network spanning multiple backend services. Engineered cross-protocol event ingestion pipeline consuming streams from three independent distributed networks with durable archiving to persistent storage. Designed real-time matchmaking engine with concurrent event processing and WebSocket-based live updates for social platform (Shonen Network).

Stack: Go, gRPC, WebSocket, event-driven architecture, distributed storage

### Protocol Engineer - Indra Labs
*Oct 2022 - Sep 2023*

Designed and implemented source-routed network transport protocol with onion-encrypted routing and relay payment channels in Go. Built gossip-based peer discovery network for decentralized node coordination. Implemented fault-tolerant message routing across unreliable distributed relay nodes. Authored protocol specification white paper.

[github.com/indra-labs/indra](https://github.com/indra-labs/indra)

### Go Developer & Technical Writer - Quanterall
*Feb - Jul 2022*

Authored comprehensive Go training curriculum for developer onboarding. Designed hybrid consensus protocol (Kismet) for distributed application chains with configurable finality guarantees.

### Backend Engineer - Dusk Network
*Oct - Dec 2021*

Contributed to Go-based distributed node software and Rust gRPC service infrastructure for a privacy-focused transaction protocol.

### Systems Engineer - Parallelcoin
*May 2018 - Sep 2020*

Built parallel work distribution system with LAN multicast UDP gossip network for low-latency task coordination across distributed workers. Designed concurrent multi-application binary combining four independent services with shared configuration and lifecycle management.

### Earlier Experience
- **Systems Engineer - Energi** (2021): Simulation framework for validating distributed system parameters
- **Independent Research** (2012-2018): Distributed consensus (Tendermint, BFT variants), Go systems programming since 2012

## Open Source

All systems and infrastructure work publicly available at [git.smesh.lol](https://git.smesh.lol/). Production relay servers, protocol implementations, and distributed systems tooling with full commit history.

## Education

Certificate IV in IT (Multimedia), QANTM College (University of Queensland consortium), Brisbane, Australia, 2003