Vladyslav Pelykh

Production incidents and hard problems I owned — what broke, how I traced it, what shipped.

• 1–6 s → <200 msPostback race on every depositAdMatrix · S2S revenue core
• 0 double-counted clicksDouble-counted clicks in ClickHouseAdMatrix · analytics
• OOM → graceful degradeOne pivot query took the whole cluster downAdMatrix · pivot engine
• 6 tabs · 0 false logoutsToken rotation that didn’t log out power usersAdMatrix · auth
• 2ⁿ bursts → serialFake 95% rate-limit and exponential burstsAdMatrix · Meta Marketing API

When there is no API, I build one. Traffic capture, JS deobfuscation, binary protocols and native hooks — turned into stable, typed integrations.

var _0x3f2a=['\x73\x69\x67\x6e','\x6a\x6f\x69\x6e','\x48\x6d\x61\x63'];
(function(_0x1,_0x2){while(--_0x2){_0x1.push(_0x1.shift())}})(_0x3f2a,0x1b3);
function _0x51(_0x9){return _0x3f2a[_0x9-0x0]}
function a(b,c,d){var e=[b[_0x51('0x1')]('&'),c,d][_0x51('0x1')]('|');
return window[_0x51('0x2')](0x2*0x8+0x10,e)[_0x51('0x0')](k)}

// decoded
{
  "id": 150,
  "handle": "pelykh",
  "team": { "size": 7 },
  "active": true,
  "role": "lead"
}

• Chrome DevTools / CDP
• mitmproxy
• Burp Suite
• Charles
• Wireshark
• Frida
• JADX
• apktool
• Ghidra
• Babel AST
• source maps
• webpack chunk graphs
• Puppeteer
• Playwright
• Protobuf wire format
• MTProto
• WebSocket frames
• HMAC request signing

1. AdMatrix — CTOERP, CRM and real-time analytics platform for an affiliate media-buying company.Feb 2026 — Present
   • Engineering leadership. Built the engineering org from zero to 7 engineers and designers; owned hiring, onboarding, code review standards, CI quality gates and the release process; drove a roadmap prioritized against revenue goals.
   • Platform architecture. Architected a ~270k LOC pnpm + Turborepo monorepo — NestJS (Fastify) API, Nuxt SPA, shared Drizzle/Zod contracts, Telegram bots and a Mini App — with one end-to-end typed contract.
   • Core revenue pipeline. Re-engineered legacy PHP postback handlers into a NestJS S2S service on 4 gateways; strict idempotency via Redis distributed locks for FTD, redeposit and LTV attribution. Latency 1–6 s → <200 ms.
   • ETL & analytics. BullMQ pipelines streaming clicks into ClickHouse (ReplacingMergeTree, monthly partitions); eliminated double-counting and cluster OOMs; real-time ROI / ROAS / CPA / EPC on bounded queries.
   • Infrastructure automation. Provisioning pipelines over Cloudflare, Namecheap and Dynadot APIs with retries and rollback for 270+ sites and 470+ domains; migrated 219 live zones with zero downtime; brought a 250-site origin outage from load 125 down to 7.
   • Security. Refresh-token rotation with reuse detection, RBAC with 60 permissions and audited overrides, AES-256-GCM field-level encryption.
   • NestJSFastifyNuxtPostgreSQLDrizzleClickHouseRedisBullMQDocker
2. DraftKings Inc. — Senior Fullstack DeveloperReal-time sportsbook infrastructure at peak-event scale.Jan 2023 — Jan 2026
   • Real-time. Scaled fault-tolerant WebSocket clusters serving 20,000+ concurrent players during peak sporting events.
   • Performance. Slashed server response time by 40% through Redis caching, query plan optimization and PostgreSQL partitioning.
   • Frontend. Spearheaded the migration to Nuxt 3 (Nitro), cutting First Contentful Paint by 35%.
   • Node.jsRedisPostgreSQLWebSocketsNuxt 3
3. Circle — Fullstack DeveloperCrypto payments infrastructure.Sep 2021 — Dec 2022
   • Payments. Engineered a high-volume USDC/BTC payment gateway on strictly idempotent APIs — zero financial discrepancies or double payouts across retries and partial failures.
   • Data. Optimized schemas and execution plans, accelerating BI transaction reporting by 60%.
   • Node.jsPostgreSQLIdempotencyCrypto
4. Y Combinator — Fullstack DeveloperY Combinator–backed startup, San Francisco (remote). Zero-to-one product work.Feb 2020 — Aug 2021
   • MVPs. Delivered 4 production-ready fullstack MVPs from scratch in tight cycles to validate seed-stage growth hypotheses.
   • Real-time. Architected Socket.IO notification infrastructure for 5,000+ concurrent users.
   • VueNode.jsMongoDBSocket.IO

• AffSource— AI video & image creatives for media buyersFounder · in development

  Prompt → ready ad creative → in-browser video editor → export. Runs self-hosted open-weight models (Wan 2.2, Qwen-Image) on rented GPUs instead of paid APIs, so each creative costs a fraction of the usual price. Batch hooks × GEOs × formats generation, live SSE progress, Web Worker export.

  Nuxt 4 · Go · ComfyUI · Canvas · Web Workers · R2 + CDN

• ORYX— USDT ledger the database enforces

  Append-only double-entry journal guarded by Postgres constraint triggers: balanced at commit, UPDATE / DELETE / TRUNCATE locked out, key-based idempotency, 18-decimal precision.

  NestJS · PostgreSQL · Drizzle

• Ares-Nexus— Order-matching engine

  Matching on Redis Sorted Sets backed by a PostgreSQL ledger. <50 ms order-to-UI and a 60 FPS PixiJS order book over throttled WebSockets.

  NestJS · Redis · PostgreSQL · PixiJS

• Ares-X & Fundory— Provably fair engine & Mini App

  HMAC-SHA512 provably fair game engine at 60 FPS on mobile; Telegram Mini App with deduplicated BullMQ rewards, initData verification and automated TRON payouts.

  Node.js · BullMQ · TronWeb · Telegram

• Pulsarr— Ad tracker — Keitaro / Binom alternative

  Go click server, NestJS API and ClickHouse reporting: campaign routing, postbacks and real-time stats.

  Go · NestJS · ClickHouse · Redis

Hiring for a lead or senior fullstack role, or have a hard problem in payments, tracking or real-time data? Write to me — I usually reply within a day.