PriceTime

PriceTime is an in-memory matching engine prototype.

What repo currently does

• Maintains limit order books in memory.
• Supports bids/asks with price priority and FIFO within each price level.
• Supports order lifecycle operations:
  • add
  • cancel
  • modify (quantity and optional price)
• Matches incoming orders against resting liquidity:
  • limit orders (must cross)
  • market orders (consume available liquidity)
• Produces trades using resting order price.
• Supports multiple instruments via separate order books per instrument.
• Uses per-book locking for safe concurrent submissions.
• Includes deterministic unit tests for:
  • order book behavior
  • matching correctness
  • multi-instrument isolation
  • basic concurrency safety

What will be added next

• Instrument rule enforcement (tick size, lot size, min size).
• Stronger validation around reject reasons and error reporting.
• Deterministic clock/sequence source for execution timestamps.
• Better observability (structured logging + execution diagnostics).
• Persistence boundary (interfaces for event/snapshot storage, still no DB coupling in core).
• Replay/snapshot support for fast warm start and reproducible backtests.
• Higher-volume concurrency and stress test coverage.