Python Developer Needed – Kalshi API / Existing BTC Trading Bot Integration

I am looking for an experienced Python backend developer to complete and audit an EXISTING Kalshi BTC 15-minute automated trading system. IMPORTANT: This project is NOT starting from scratch. Most of the infrastructure is already built, deployed, and running 24/7 on a DigitalOcean Ubuntu VPS. CURRENT SYSTEM ALREADY HAS: - Python BTC 15-minute signal bot - DigitalOcean / Ubuntu VPS - systemd services running 24/7 - SQLite databases and logging - Kalshi Demo API integration already working - Kalshi Production API authentication already configured - Real Kalshi account balance reading - Real BTC 15-minute market price reading - UP / DOWN signal detection - Real-time signal watcher - Position sizing based on account balance - Risk percentage calculation - Entry price/slippage validation - Dry-run / shadow execution system - Existing Demo order execution implementation The current production system can already detect a new BTC signal, read the corresponding REAL Kalshi market, compare the real price against the signal price, calculate the correct number of contracts, and validate whether the trade should be executed. WHAT I NEED: I need a developer to review the existing codebase and safely complete/audit the production order execution layer. The intended workflow is: BTC signal generated → UP or DOWN direction selected → Read current Kalshi production price → Validate entry price and signal age → Calculate position size → Submit order → Verify actual fill → Monitor position → Manage exit conditions → Reconcile final position/order status → Log complete trade lifecycle The developer must have strong experience with trading/exchange APIs and understand that simply submitting an HTTP request is NOT enough. Reliability and safety are very important. REQUIRED SAFEGUARDS: - Duplicate-order prevention / idempotency - Protection against repeated signals - Partial-fill handling - Order status reconciliation - Position reconciliation - API timeout/error handling - Retry logic without duplicate orders - Race-condition protection - Maximum position/risk limits - Maximum acceptable entry price - Stale-signal rejection - Emergency kill switch - Safe restart/recovery behavior - Detailed execution logs - Secure API credential handling - Ability to verify actual fills instead of assuming orders filled TECH STACK: - Python - REST API - Linux / Ubuntu - DigitalOcean VPS - systemd - SQLite - RSA/API authentication - Kalshi API Experience with Kalshi is preferred, but strong experience with brokerage, crypto exchange, prediction market, or trading APIs is also acceptable. I DO NOT want the system rebuilt from scratch. The first task will be to review the existing architecture and explain what needs to be changed before modifying production execution. Before giving server access, I can provide an overview of the current code and architecture. API private keys, passwords, and other credentials will NOT be shared through Upwork messages. When applying, please answer: 1. Which trading or exchange APIs have you integrated? 2. Have you implemented automated order execution before? 3. How do you prevent duplicate orders when an API request times out? 4. How would you handle partial fills? 5. Have you deployed persistent Python services using systemd on Linux? 6. Do you have experience with Kalshi or prediction-market APIs? 7. Can you work with an existing codebase instead of rebuilding it? Please include examples of relevant previous work, GitHub projects, or similar systems if available. Fixed-price project. Budget is approximately $600, depending on experience and scope after reviewing the existing code.