Стас

STAS POPERECHNYI

Python Developer with DevOps Experience

Phone: [відкрити контакти](див. вище в блоці «контактна інформація») | Email: [відкрити контакти](див. вище в блоці «контактна інформація») | Location: Barcelona, Spain (Remote)

SUMMARY
Python Developer with 3 + years building high-performance cryptocurrency platforms. Delivered
50x performance improvements, 85% cost reductions, architected systems handling 500+
concurrent users with <100ms latency and 97.3% uptime on $5M+ daily volume. Expert in
microservices, async Python, database optimization, and production infrastructure.

TECHNICAL SKILLS
Core: Python 3.11+ (asyncio, FastAPI, Django, Flask, Celery), JavaScript, Solidity | Data:
PostgreSQL, Redis, SQLAlchemy 2.0, query optimization | DevOps: Docker, Kubernetes, GitLab
CI/CD, AWS, Nginx, Prometheus, Grafana | Security: JWT, Argon2id, AES encryption, MFA/TOTP

EXPERIENCE
Python Developer with DevOps October 2025 - March 2026 | Remote (NDA)

Built non-custodial perpetual futures DEX: off-chain CLOB matching + on-chain settlement via
Solidity vault.

Performance & Architecture:
• Async Python CLOB engine: ~1-2ms match latency, persistent Redis orderbook with crash
recovery from DB in <2 min
• Multi-source mark price oracle (5-exchange VWAP, outlier rejection, 30s staleness halt) with
circuit breaker (HALTED/DRAINING/per-pair)
• Atomic balance ops: SQLAlchemy `FOR UPDATE` row locks + Redis RedLock, idempotent
settlement ledger with batch-hash dedup

Core Systems:
• Vault smart-contract integration (Web3.py async): margin lock/unlock, batch P&L settlement,
2-step withdrawal with 48h trustless timelock, cross-chain bridge events
• Liquidation engine: graduated partial mode, ADL waterfall, insurance fund, socialized loss
• 8h funding payments with TWAP premium index, leverage tiers (8 levels by notional), self-trade
prevention

DevOps & Reliability:
• Crash recovery: orderbook rebuild, settlement retry queue, event listener resume from Redis
last-block
• Celery beat tasks (vault event scan, settle batch, margin sync, withdrawal review,
reconciliation, funding)
• Multi-repo coordination across 5 services (exchange backend, market maker, bridge relayer,
auth, admin)
• Edge nginx with Let's Encrypt auto-renew, Prometheus + Grafana + Loki + Promtail, GitLab
CI/CD

Technologies: Python 3.11+, FastAPI, SQLAlchemy 2.0 async, PostgreSQL 15, Redis 7, Celery,
Web3.py, Solidity (EVM), Docker, Nginx, Prometheus, Grafana

Python Developer with DevOps September 2023 – October 2025 | Remote

Led development of cryptocurrency trading platform serving 1500-1700 concurrent users, $5M+
daily volume, 97.3% uptime.

Performance Optimization:

●​ Achieved 50x faster balance operations (250s → 5s) through parallel processing
and intelligent caching
●​ Reduced database query time by 80% with strategic indexing (composite, functional,
●​ partial indexes)
●​ Optimized memory usage: 65% reduction in stream processing while maintaining
performance
●​ Improved data refresh speed 4x (10s → 2.5s) using Redis pipelines
●​ Reduced external API calls by 70% through batching and request optimization
●​ Achieved 70% cache hit rate with multi-level Redis strategy (5s to 5min TTL)

Architecture & Scale:

●​ Built authentication service: 400-600 concurrent sessions, 200-400 req/sec, <10ms token
generation
●​ Developed WebSocket infrastructure: 5000+ concurrent connections, real-time market
updates
●​ Created orderbook engine: 100-200 orders/sec, <50ms P95 latency, 150,000+ Redis ops/sec
●​ Implemented distributed proxy pool: 50,000+ API requests/minute capacity

Core Systems:

●​ Futures Trading Platform: 1x-25x leverage, event-driven liquidation (<100ms reaction,
), matching engine (1000+ orders/sec), stop-loss/take-profit (<1s trigger)
●​ Auth Microservice: JWT with RS256, Argon2id, TOTP MFA, distributed rate limiting, 800-1200
req/sec registration throughput
●​ API Key Service: AES-128 encryption, 50x performance improvement, 160+ tests,
76%+ coverage, <50ms response
●​ Market Data Service: 686+ pairs, 1000+ alerts/30sec, notification batching (60%
API reduction), <200ms P95

DevOps & Infrastructure:

●​ Architected automated CI/CD: <1 min rollback, 5-7 min deployment cycles
●​ Built monitoring: Prometheus + Grafana (39+ metrics), intelligent alerting, structured logging
●​ Managed infrastructure: Docker, Nginx (TLS 1.2/1.3), PostgreSQL cluster, Redis cluster
●​ Security: HD wallets (BIP32/BIP44), AES-256 encryption, JWKS verification, IP
whitelisting, audit trails

Technologies: Python 3.11+, FastAPI, SQLAlchemy 2.0, PostgreSQL, Redis, Celery, Docker, GitLab
CI/CD, Prometheus, Grafana, AWS, Binance/Bybit API

Python Developer | RI Software​ September 2022 – December 2023
| Remote

Built microservices for 5,000+ users across 4 web services.

●​ Optimized APIs: ~30% faster response times through database query optimization
●​ Implemented Repository and Unit of Work patterns
●​ Developed Vue.js frontend features with REST integration

Stack: Python, Flask, FastAPI, Vue.js, SQLAlchemy, PostgreSQL, Docker

Python Developer | Jeton P2P Bot​ May 2023 – September 2023 | Remote

Developed Telegram P2P crypto bot: 2000+ users
●​ Built P2P transaction system with escrow and dispute resolution
●​ Cryptocurrency integration: Bitcoin, Ethereum, Tron (Web3.py)

Stack: Python, aiogram, SQLAlchemy, Web3.py, PostgreSQL

Python Web3 Developer | Freelance​ April 2023 – June 2023 |
Remote

Blockchain automation: LayerZero, ZkSync ecosystems

Stack: Python, web3.py, BeautifulSoup4

EDUCATION
Hillel IT School — Python Pro | 2022

Odessa Polytechnic University — Bachelor's in Automation & Computer Technologies | 2026
(Expected)

LANGUAGES
English: Upper-Intermediate (B2) | Ukrainian: Native | Spanish: Beginner