← Back
Home › Systems › Transport, logistics and mobility

car-rental

rental reservation/fleet platforms, mostly internal

Enterprise, Hertz, Avis Budget; peer-to-peer Turo

SystemTechniques · 13Primitives · 62 car-rental Saga patterndistributed · medium: Split a cross-service operation into local transactions, each paired with an undo; on failure run the undos in reverse, or retry forward.›Inventory reservationfinance · medium: Reserving stock with TTL holds, release on timeout and no overselling under contentionPayment state machinefinance · medium: Persisted state machine for a payment lifecycle (authorize, capture, void, refund) that treats timeouts as unknown, retries with the same key and applies webhooks idempotently.›Revenue management emsrfinance · medium: EMSR-b booking limits and bid prices for perishable capacity (seats, rooms)Min cost flowgraphs · medium: Minimum-cost flow (successive shortest paths, network simplex) for distribution and rebalancingGradient-boosted decision trees (GB…machine-learning · medium: Add small regression trees one at a time, each fitted to the loss gradient; histogram splits over 256 bins make it the strongest tabular default.›Object detectionmachine-learning · medium: A network turns an image into scored, classified boxes in one pass; anchor-based, anchor-free and set-prediction heads differ in how they assign labels and remove duplicates.›Idempotency keysfinance · low: Client-chosen unique key per logical operation, stored with a request fingerprint and the final response, so retries replay the first result instead of acting twice.›Simplex methodoptimization · low: Solves linear programs by walking along the edges of the feasible polytope from vertex to vertex, one basis swap (pivot) at a time; the workhorse behind MIP solvers.›Leasesdistributed · low: A lock that expires on its own: bounded-time ownership that survives crashes and partitions, given bounded clock drift and fencing tokens on writes.›Sharded countersconcurrency · low: Split one hot counter into per-core or per-thread cells on separate cache lines; increments stay local and reads sum the cells.›Interval treedata-structures · low: Index of ranges that answers "which intervals overlap this point or range?" in O(log n + k); static sorted-array form is the compact, cache-friendly choice.›Can bus framingembedded · low: CAN / CAN FD frames, bitwise arbitration, bit stuffing, CRC and error confinementMoney representationfinance · low: Store money as integer minor units with an explicit currency exponent, compute in wider integers, and round once with a named rounding mode.›Geodesic distance (haversine, Vince…geometry · low: Shortest-path distance between two lat/lon points on the Earth: haversine on a sphere (about 0.5% error), Vincenty or Karney on the WGS84 ellipsoid (sub-millimetre).›Point in polygongeometry · low: Ray-casting/winding tests and indexed polygon lookup for reverse geocodingLinear and logistic regressionmachine-learning · low: Fit a weighted sum of features to a number (least squares) or a probability (logistic); the baseline every model must beat.›Mqtt protocolnetworking · low: MQTT pub/sub: topics, QoS 0/1/2, retained messages, sessions and keepaliveBle gattsignal-processing · low: Bluetooth LE link layer, ATT/GATT services and characteristics, connection intervals and pairingOptimistic concurrency controlstorage · low: Run transactions without locks, record what they read, and validate at commit that nothing changed; fastest when conflicts are rare.›Calendar date arithmeticsystems · low: Civil dates, time zones (tzdb), DST gaps, month-end anchoring and duration mathConditional writesdistributed · low: Put-if-absent / if-match compare-and-swap on objects or keys as a commit primitiveHierarchical timing wheelsystems · low: Timers bucketed by expiry into wheels of slots, coarser wheels for far deadlines: O(1) insert and cancel for millions of timeouts.›+ 6 more techniques+ 46 more primitives

Similar systems

Share the most building blocks with this one.

booking 28 %dynamic-pricing 21 %virtual-economy 21 %micromobility 21 %theme-park-ops 20 %