Vadim Seliukov

Backend & AI-Systems Engineer

+380 67 419 6755

Prague · Remote · UTC+1 (authorized to work in the EU)

Backend-focused engineer with 3+ years shipping production systems: APIs, data pipelines, integrations, and AI-agent infrastructure. Strong in Python / FastAPI and getting AI agents to act reliably and safely. Creator of ezRPC (open-source HTTP/3 RPC framework) and Cushio (open-core AI-agent reliability & safety layer).

Experience

Backend & Data Engineer · Newly Booked

Aug 2023 – Present

Owned backend, data, and integration systems end-to-end for a booking & operations platform, working closely with the founders and the sales and ops teams · Remote

Built a custom, Airflow-like data-orchestration platform from scratch: a scheduler running ~14 prioritized worker tasks, each on its own interval, with retries, backfills, and load-based auto-scaling across processes/threads, normalizing 13+ sources (GoHighLevel, Twilio, Meta, Google Analytics, Google Sheets, internal services) into a MongoDB source of truth at ~99.8% uptime.
Built the analytics + AI layer: embedded 1.5M+ messages, 100k+ conversations, and 1.2M+ calls (OpenAI embeddings, MongoDB Atlas Vector Search) to power semantic search and analytics over sales and call-center interactions, surfacing conversation mistakes and lifting conversion rate by 18%.
Integrated CRM, calendar, booking, and telephony platforms (GoHighLevel, Twilio, Monday, Google), including no-official-API services, using idempotent syncs and retry/reconciliation logic.
Built 100+ production automations (n8n) across lead intake, call transcription, appointment lifecycle, onboarding, and reporting, removing an estimated 30–50 hrs/week of manual ops.

Freelance Developer · Upwork

Mar 2023 – Aug 2023

Built websites and Python automation/scripting for international clients · Remote

Selected Projects

Cushio

open-core · cushio.ai

A reliability & safety net for AI agents that take real actions: execution receipts, outcome-aware idempotency, and a queryable, undoable action ledger. Open-core, in active development. Python, FastAPI, PostgreSQL, MCP.

ezRPC

open-source · github.com/kermit-frogs19/ezRPC

A FastAPI-style RPC framework for HTTP/3, built on aioquic with MessagePack. Brings familiar Python ergonomics (routing, typed models) to QUIC, with companion HTTP/3 and HTTP clients.

Skills

AIAI-agent engineering, LLM integration, tool use / MCP, vector search / embeddings, agent reliability & safety

BackendPython, FastAPI, Django, Node.js, Express.js, NestJS, Kafka, HTTP/3

DataPostgreSQL, MySQL/MariaDB, MongoDB, DynamoDB, SQLite, data engineering, Airflow, Databricks

ScrapingWeb scraping (Playwright, patchright), undocumented-API integration, integration design

CloudAWS, Cloudflare, Fly.io, DigitalOcean, Docker, Kubernetes, Git, GitHub Actions

FrontendReact, Next.js, TypeScript; automation with n8n, GoHighLevel

Education

MSc, Computer Engineering (System Engineering)

Kharkiv National University of Radio Electronics (KhNURE)

2025 – Present

BSc, Computer Engineering

Kharkiv National University of Radio Electronics (KhNURE)

2021 – 2025