1. Handling Encrypted Position Data With Arcium

The challenge:
When I first integrated Arcium MPC, the decrypted values for position size were coming back as huge unusable numbers. This broke fee calculations and prevented users from closing positions because the system thought they owed massive fees.

How I solved it:

• Added validation to detect corrupted or invalid decrypted values
• Calculated position size using known values (collateral, leverage, ZEC price) as a fallback
• Added sanity checks to cap fees and PnL for safety

This made encrypted computation reliable and allowed positions to close correctly.

---

2. USD (6 decimals) vs wZEC (8 decimals) Unit Mismatch

The challenge:
PnL was calculated in USD but collateral was in wZEC. Mixing these units caused wrong payouts and users losing collateral after closing positions.

How I solved it:

• Introduced

  zec_price

  into all relevant calculations
• Explicitly converted every value between USD ↔ wZEC
• Updated both frontend and program logic to maintain consistent units

After fixing this, payouts and margin checks became accurate.

---

3. Zcash Node Sync & RPC Issues for the Private Bridge

The challenge:
The first Zcash Docker image I used was outdated and never synced. RPC calls also failed due to authentication issues, blocking the entire private ZEC → wZEC bridge flow.

How I solved it:

• Switched to the official

  electriccoinco/zcashd

  image
• Fixed RPC settings and added proper authentication
• Added error-handling for import/viewing key issues
• Ensured the relayer can reliably detect shielded deposits

This made the private bridge stable and testable.

---

4. Anchor & TypeScript Type Errors

The challenge:
Anchor types were causing deep instantiation errors and the Arcium client imports behaved differently across environments.

How I solved it:

• Used

  as any

  where Anchor types became too complex
• Added proper

  BufferSource

  casting for crypto operations
• Used dynamic imports for Arcium client packages

This unblocked development and kept the codebase maintainable.

---

5. Position Reuse Issues

The challenge:
Users couldn’t open a second position because Anchor accounts were created with

init

, which only works once.

How I solved it:

• Replaced

  init

  with

  init_if_needed

• Added logic to reuse inactive position accounts

This allowed seamless opening/closing of multiple positions.

---

Summary

Most challenges came from combining three complex systems:

• Encrypted computation (Arcium MPC)
• Cross-chain shielded deposits (Zcash → Solana)
• High-performance on-chain logic (Solana/Anchor)

Solving these forced me to build reliable fallbacks, strict unit-handling, improved error logging, and a much more robust architecture overall.