LAB / REPLAY-01
OPERATIONAL
POINT-IN-TIME REPLAY LAB
The signature demonstration: select a timestamp on a synthetic series and observe the information boundary — what was knowable at t, and what only existed after.
IN — TIMESTAMP · SCRUB · REPLAY SPEED
OUT — VISIBLE AT t · FUTURE-DATED · LOOKAHEAD DEMO
INSTRUMENT / REPLAY-01
INPUTS DECLARED · OUTPUTS DERIVED
VISIBLE AT t: 24 CANDLESFUTURE-DATED: 18 CANDLES
A query at t can only read the solid candles. The ghosted region is information that did not yet exist — in a naive backtest it silently leaks in (lookahead); in point-in-time infrastructure it is structurally unreachable. Series is deterministic and synthetic.
LOOKAHEAD VS POINT-IN-TIME SAFE
THE FAILURE MODE
LOOKAHEAD
- A resampled candle quietly includes the tail of its window
- A join keys on knowledge that only existed after the fact
- A timestamp normalizes to a coarser clock and rewrites causality
- The result cannot be repaired — only regenerated from clean data
THE STRUCTURAL ANSWER
POINT-IN-TIME SAFE
- Reads at time t can only resolve information that existed at t
- The guarantee lives in the data layer — consumers cannot opt out
- Sliding watermark defines the visible horizon for every reader
- Adversarial tests attack the boundary and fail — verified