flowchart TB C1["Consume batch
up to 1,000 statements or 200ms (Kafka Consumer Batch Window)"]:::main C2["Pseudonymize + resolve + enrich"]:::main C3["BKT Streaming Update
per (student, concept), in partition order"]:::main C4["Write batch to ClickHouse
ReplacingMergeTree Dedup absorbs redelivered rows"]:::main C5["Checkpoint mastery state
Compacted State Checkpoint topic"]:::ckpt C6["Commit Kafka offset"]:::main L1["Late Arrival Detector
statement far behind the watermark"]:::late L2["Enqueue Targeted Replay Command
scoped to (student, concept)"]:::late L3["Recompute mastery trajectory in order
directly from the ClickHouse log"]:::late C1 --> C2 --> C3 --> C4 --> C5 --> C6 C1 --> L1 L1 --> L2 --> L3 L3 --> C5 classDef main fill:#2a9d8f,stroke:#1f7a6f,color:#fff,font-size:13px classDef late fill:#e9a23b,stroke:#b8791f,color:#222,font-size:13px classDef ckpt fill:#7b6cc4,stroke:#544a91,color:#fff,font-size:13px linkStyle default stroke:#999,stroke-width:2px