1. Zcash Node Synchronization & Connectivity
Challenge: Setting up and syncing the Zcash node (migrating from zcashd to Zebra) proved extremely challenging. Initial connection issues prevented block downloads, and syncing to mainnet took considerable time.

Solution: We containerized the infrastructure using Docker, configured lightwalletd for efficient transaction monitoring, and implemented robust retry mechanisms in the LightwalletdService to handle network interruptions gracefully.

2. Real-time Transaction Monitoring
Challenge: Detecting incoming Zcash deposits in real-time, including mempool transactions before confirmation, required careful orchestration to avoid duplicates while ensuring no transactions were missed.

Solution: Built a custom polling service that monitors both confirmed blocks and mempool, using Redis to track processed transaction IDs and last scanned heights for resumability.

3. Cross-Chain Swap Integration
Challenge: Integrating ZEC ↔ USDC swaps was complex. We initially explored SwapKit/THORChain but encountered "swap halted" errors, requiring us to pivot to Near Intent's OneClick SDK.

Solution: Implemented a flexible SwapService with proper intent creation, status polling, and timeout handling. Added refund mechanisms to return funds to users if swaps fail.

4. Hyperliquid API Stability
Challenge: The Hyperliquid SDK threw HyperliquidAPIError: No response received from server during initialization and WebSocket processing, causing unhandled promise rejections and application crashes.

Solution: Wrapped SDK calls with comprehensive error handling, implemented exponential backoff retries, and added graceful degradation so the application continues running even during API outages.

5. Temporal Workflow Reliability
Challenge: Orchestrating the complex multi-step deposit→swap→bridge→trade flow with proper error handling, retries, and state management was difficult. "Failed to start deposit workflow" errors appeared intermittently.

Solution: Leveraged Temporal's durable execution guarantees, configured appropriate timeouts and retry policies, and implemented proper activity separation for each step of the flow.

6. Bridging USDC to Hyperliquid
Challenge: After swapping ZEC to USDC on Arbitrum, bridging funds to Hyperliquid's L1 for perp trading required tracking balance changes and implementing polling with timeouts.

Solution: Implemented balance polling loops in workflows with configurable timeout periods, ensuring funds are confirmed on Hyperliquid before trade execution.

7. Memo Parsing & Instruction Validation
Challenge: The entire user experience depends on correctly parsing JSON memos from Zcash transactions. Malformed memos or unsupported instructions needed graceful handling.

Solution: Implemented schema validation for memo parsing with clear error responses and refund mechanisms for invalid instructions.