🚀 Sui Fundamentals: How to Think About the Network & Build Reliable Apps

Problem this solves Many teams new to Sui come in with an EVM mindset — packing everything into one monolithic contract, assuming transactions run sequentially, and reusing the same gas coin. ❌ The result? Hotspots, failed transactions, and poor scalability.

Goal This guide gives you a clear step-by-step mental model for designing Sui applications that are reliable, scalable, and developer-friendly. 🛠️

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🔑 1) Key Mental Model: Objects, Owners & Move

On Sui, everything is an object.

• Each has a unique ObjectID.

• Objects can be:

  • 👤 Address-owned → only the owner mutates.
  • 🤝 Shared → multiple participants can access.
  • 🪶 Immutable → fixed forever (great for templates).

👉 Design tip: Break your data into many small objects instead of one global state. This unlocks Sui’s parallel execution superpower.

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⚡ 2) What Causes Common Failures (and How to Spot Them)

🔴 Version conflicts

• Each transaction references specific object versions.
• If another tx updates it first, yours fails.
• Clue: bursty failures with “object version mismatch” errors.

🔥 Hot objects

• Everyone writing to the same global object → serial execution.
• Clue: one ObjectID shows up in nearly all transactions.

🪙 Gas coin contention

• Using the same coin object for parallel submissions causes a bottleneck.
• Clue: multiple users tx stuck on the same gas coin.

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🛠️ 3) Step-by-Step Design Rules

1. Model every entity as its own object ✨

   • Users, vaults, orders, positions — each gets its own struct.

2. Pick ownership wisely

   • 👤 Wallet-owned → private data.
   • 🤝 Shared → collaborative features (games, order books).
   • 🪶 Immutable → templates/configs.

3. Partition shared state

   • Don’t use one “global marketplace.”
   • Use sharding: by creator, price bucket, or hashed key.

4. Avoid re-using the same gas coin

   • Split gas coins per session.
   • Each tx should have its own gas coin.

5. Use events for off-chain indexing 📡

   • Don’t bloat on-chain storage with derived indices.

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👩‍💻 4) Client Flow to Avoid UX Surprises

Build your client around a state machine:

1. 📝 Pre-submission → prepare transaction.
2. 🚀 Submitted → send to network.
3. ✅ Executed (effects) → use execution effects for accurate reads.
4. 🔒 Checkpointed (final) → transaction finalized.

👉 If a tx fails due to version mismatch:

• Re-fetch only the impacted objects.
• Retry with updated versions.

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🧪 5) Dev & Test Habits

• 🧰 Dry-run & simulate before committing.
• 👥 Stress-test concurrent users hitting the same shard.
• 🔑 Keep admin capabilities in isolated objects (don’t mix with user state).

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✅ 6) Production-Readiness Checklist

• Objects are granular (no global blobs).
• Ownership is explicit & documented.
• High-traffic state is sharded.
• Client has retry logic for version conflicts.
• Events are used for off-chain indexing.

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🌟 Why This Helps

By embracing Sui’s object-first mindset, you:

• Unlock parallel execution (better throughput ⚡).
• Avoid hotspots & puzzling failures ❌.
• Deliver apps that scale naturally with Sui’s architecture.

👉 For more, check out the [Official Sui Docs][1] and [Developer Portal][3].

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✨ In short: Think objects, not accounts. Shard, don’t centralize. Retry, don’t panic.