Cancer free

As a Smart Contract Engineer, Slap yourself if you cannot clearly explain at least 10 of the following: 1. EVM memory vs storage vs calldata layout 2. Storage slot packing & inheritance slot collisions 3. Transient storage (EIP-1153) use cases 4. delegatecall context preservation & storage layout traps 5. Proxy patterns: Transparent vs UUPS vs Beacon 6. Storage gaps in upgradeable contracts 7. Diamond pattern (EIP-2535) & facet selector clashes 8. Function selector collisions & 4-byte clashing attacks 9. ABI encoding vs encodePacked hash collisions 10. Checks-Effects-Interactions ordering 11. Reentrancy: single-function, cross-function, cross-contract, read-only 12. ERC-777 hooks & callback reentrancy surface 13. Gas griefing via return-bomb / unbounded returndata 14. 63/64 gas forwarding rule (EIP-150) 15. try/catch failure modes & bubbling reverts 16. Custom errors vs require strings gas trade-offs 17. SafeMath obsolescence & 0.8 overflow semantics 18. Unchecked blocks: when they're safe 19. Signed vs unsigned integer pitfalls in arithmetic 20. Fixed-point math & precision loss ordering 21. Front-running & sandwich attack mechanics 22. Commit-reveal schemes & MEV mitigation 23. Flashloan-based price oracle manipulation 24. TWAP oracles & manipulation cost analysis 25. EIP-712 typed structured signing 26. Signature malleability & ecrecover(0) handling 27. Replay protection across chains (chainId binding) 28. Permit (EIP-2612) & gasless approvals 29. Nonce management for meta-transactions 30. Account abstraction (EIP-4337) UserOp lifecycle 31. EIP-7702 set-code-for-EOA implications 32. CREATE vs CREATE2 address derivation 33. Metamorphic contracts & selfdestruct redeployment 34. selfdestruct post-Cancun (EIP-6780) semantics 35. Init-code vs runtime bytecode distinction 36. Immutable vs constant storage mechanics 37. Gas refund mechanics & SSTORE gas accounting (EIP-2929/3529) 38. Access list transactions (EIP-2930) 39. Warm vs cold storage access costs 40. Yul / inline assembly memory safety 41. Free memory pointer (0x40) discipline 42. Scratch space (0x00–0x3f) misuse 43. Bit manipulation & masking for packed structs 44. ERC-20 approve race condition 45. Fee-on-transfer & rebasing token integration breakage 46. ERC-721 safeTransfer reentrancy via onERC721Received 47. ERC-1155 batch transfer accounting 48. ERC-4626 vault inflation / donation attacks 49. First-depositor share-price manipulation 50. Rounding direction (round up vs down) in vault math 51. Pull-over-push payment patterns 52. Block.timestamp manipulation bounds 53. blockhash limitations & on-chain randomness fallacies 54. VRF integration & request-fulfill patterns 55. Merkle proof verification & second-preimage attacks 56. Bitmap-based airdrop claim tracking 57. Multicall & msg.value reuse across calls 58. Delegatecall to untrusted code 59. tx.origin phishing vector 60. Gas-efficient storage clearing for refunds 61. Packed storage write ordering for gas 62. Cross-contract call gas stipend assumptions 63. Forced ETH via selfdestruct breaking invariants 64. Initialization front-running on proxies 65. Signature replay across forks 66. L2 sequencer downtime oracle staleness 67. Optimistic rollup 7-day withdrawal mechanics 68. Blob transactions (EIP-4844) & calldata cost shifts 69. Precompiles (ecrecover, modexp, pairing checks) 70. BLS signature aggregation verification 71. Reentrancy guards vs transient storage locks And if you only know 10 — kindly return the "Senior Smart Contract Engineer" title.

As a Backend Developer, Slap yourself if you cannot clearly explain at least 10 of the following: TCP congestion control algorithms TLS 1.3 handshake internals HTTP/2 multiplexing & HPACK HTTP/3 QUIC packet loss recovery Connection pooling pitfalls Zero-downtime deployment strategies Database transaction isolation levels (serializable vs snapshot) B-tree vs LSM-tree index internals Query planner & cost-based optimization Deadlock detection & prevention ACID vs BASE trade-offs Two-phase commit vs Saga pattern Distributed locking (Redlock pitfalls) CAP theorem in practice CRDTs & conflict-free replicated data types Eventual consistency anti-patterns Kafka partition rebalancing & exactly-once semantics RabbitMQ dead-letter queues & message ordering gRPC streaming flow control GraphQL resolver batching & N 1 problem OAuth2 token introspection vs JWT validation Rate limiting algorithms (token bucket vs leaky bucket) Circuit breaker bulkhead patterns Observability: OpenTelemetry tracing propagation Prometheus metric cardinality explosion Log aggregation with sampling Memory-mapped files vs traditional I/O Garbage collection tuning (G1 vs ZGC) Thread pools vs virtual threads (Project Loom) Actor model vs shared-memory concurrency Message-driven architecture (Akka / Orleans) CQRS Event Sourcing projections Outbox pattern for reliable events Sharding strategies & hot partition avoidance Read replicas lag monitoring Database connection pool exhaustion Prepared statement caching Index bloat & vacuum strategies Kubernetes pod disruption budgets Service mesh traffic shifting Serverless cold-start mitigation API gateway throttling & caching layers Background job queues (Celery / BullMQ) retry semantics Distributed cache invalidation (cache-aside vs write-through) Eventual consistency in cache Idempotency keys in API design Optimistic locking with version vectors Paxos / Raft consensus internals Byzantine fault tolerance basics Chaos engineering principles Database failover & split-brain prevention Microservices observability (distributed tracing) API contract testing (Pact / Spring Cloud Contract) Backward-compatible schema evolution Protobuf vs JSON performance trade-offs Binary protocol parsing Zero-copy networking (sendfile) epoll / kqueue internals Syscall overhead & context switching Memory barriers & CPU cache coherence Lock-free data structures Bloom filters & HyperLogLog in practice Consistent hashing for load balancing Virtual memory & page faults impact Container runtime security (seccomp, AppArmor) Sidecar pattern limitations Service discovery (Consul vs DNS) Blue-green vs canary deployments Feature flags with rollout strategies Data pipeline backpressure handling Exactly-once processing guarantees Idempotent consumers in event streams And if you only know 10 — kindly return the “Senior Backend Developer” title. 😄

Building an on-chain crowdfunding app, but not the regular kind. Builders define milestones upfront, and contributors vote to release funds at each stage. No disappearing with the treasury, no blind trust, just transparent execution and accountability. Lets see how the build goes

Let's get into it. Building a lottery smart contract on with @solidity_lang on @CyfrinUpdraft

I can’t even advice anyone to get into tech especially product design now. You’re better off learning carpentry or plumbing.

1st exam today was a success 🔥. Tomorrow next. Wish me luck 😭🤌