OPTION A – Hybrid (Binance + 3Commas) Senior Python Engineer – Advanced Crypto Trading Engine (Binance + 3Commas Hybrid) DESCRIPTION I am looking for a senior backend engineer to design and implement a production-grade multi-tier crypto trading engine. The system will integrate directly with Binance API and optionally use 3Commas as the execution layer (signal bots). This system will manage real capital and must be fully autonomous once deployed. Autonomous Requirements: • No manual trade confirmations • Automatic recovery after crashes • Automatic reconciliation after downtime • Deterministic state persistence Core Functional Requirements: • Multi-tier capital allocation engine • Global anti-overfill protection across tiers • Strict exposure control per asset • Idempotent trade execution safeguards • Partial fill handling • Cooldown logic between tier activations • Reinvestment logic after profit cycles • Protection against race conditions • Protection against API latency and retries Technical Requirements: • Python backend (FastAPI preferred) • PostgreSQL as source of truth • Redis (or equivalent) for locking • Binance REST + Websocket integration • Optional 3Commas execution via signal bots • Dockerized deployment • Structured logging System must implement safeguards ensuring: • No duplicate execution • No tier over-allocation • No exposure drift after restart • Consistent synchronization with exchange state Deliverables: • Git repository • Docker compose setup • DB schema documentation • Test suite (duplicate prevention, anti-overfill, restart recovery) • Operational runbook Timeline: 4 weeks or less Milestone-based payments only Before bidding, please answer: Have you built production crypto trading systems before? How would you implement global anti-overfill protection? How would you handle reconciliation after downtime? Would you execute directly via Binance or via 3Commas? Why? OPTION B – Pure Binance Engine (No 3Commas) Senior Python Engineer – Production-Grade Binance Trading Engine DESCRIPTION I am looking for a senior backend engineer to build a deterministic, production-grade multi-tier trading engine integrating directly with Binance API (Spot and/or Futures). No third-party execution layers. This system will manage real capital and must operate fully autonomously. Autonomous Requirements: • No manual confirmations • Automatic crash recovery • Automatic reconciliation after downtime • Deterministic state tracking Core Functional Requirements: • Multi-tier capital allocation logic • Global anti-overfill safeguards • Strict exposure governance • Idempotent execution controls • Partial fill handling with dynamic recalculation • Cooldown enforcement • Profit reinvestment logic • Concurrency protection • Retry & backoff logic for API errors Technical Stack: • Python (FastAPI preferred) • PostgreSQL (source of truth) • Redis (locking & concurrency control) • Binance REST + Websocket integration • Dockerized deployment • Structured logging & monitoring System must implement safeguards ensuring: • No duplicate trades • No tier capital over-allocation • No exposure drift after restart • Full exchange reconciliation before resuming trading Deliverables: • Clean Git repo • Docker compose • DB schema documentation • Test suite (duplicate prevention, anti-overfill, restart recovery) • Operational runbook Timeline: 4 weeks or less Milestone-based payments only Before bidding, please answer: Have you built Binance trading systems before? How do you implement idempotent order execution? How do you handle reconciliation after downtime? How do you protect against race conditions?