mhtirogla
Home
Systems
API
Pricing
About
Log in
← Back
Home
›
Systems
›
Finance and trading
smart-order-router
smart order router
broker SOR
System
Techniques · 4
Primitives · 39
smart-order-router
Clock synchronization
distributed · medium: Estimate a clock's offset from four timestamps, filter out queueing noise, and steer the clock smoothly; NTP gets about a millisecond, PTP with hardware timestamps under a microsecond.
›
Execution algorithms
finance · medium: TWAP, VWAP, POV and implementation-shortfall slicing of parent orders into child orders
Market impact models
finance · medium: Transaction-cost and market-impact estimation (square-root law, Almgren-Chriss) for routing and simulation
Order lifecycle state machine
finance · medium: Order states (new, partial fill, cancel/replace, rejected, expired) with strict transitions and idempotent events
Limit order book
finance · low: Per-symbol store of resting orders as FIFO queues per price level; array-indexed ticks plus intrusive lists give O(1) add, cancel and best-price lookup.
›
Sequenced multicast feed
networking · low: Exchange order-by-order data as fixed binary messages in sequenced UDP multicast packets
Hierarchical timing wheel
systems · low: Timers bucketed by expiry into wheels of slots, coarser wheels for far deadlines: O(1) insert and cancel for millions of timeouts.
›
Linear and logistic regression
machine-learning · low: Fit a weighted sum of features to a number (least squares) or a probability (logistic); the baseline every model must beat.
›
FIX protocol (session layer)
finance · low: Tag=value order-entry protocol over TCP with per-direction sequence numbers, heartbeats and resend so sessions survive disconnects without losing or duplicating orders.
›
Idempotency keys
finance · 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.
›
SPSC ring buffer
data-structures · low: Bounded wait-free queue for exactly one producer and one consumer thread, built from an array and two indices with acquire/release ordering.
›
Low-latency hot path
finance · low: Rules for microsecond trading paths: one pinned busy-polling thread per stage, no allocation, syscalls, locks or page faults after startup, kernel-bypass I/O, and measured tails.
›
Pre-trade risk checks
finance · low: Constant-time gate in front of order entry that rejects fat-finger, over-limit and runaway orders using worst-case exposure counted over open orders.
›
PID controller
robotics · low: Drive a measured value to a setpoint with three terms on the error: proportional, integral, derivative. The default feedback loop for motors, heaters, drones and gimbals.
›
Phase-locked loop (digital)
signal-processing · low: Feedback loop that locks a local oscillator to the phase and frequency of an input tone; the core of carrier recovery, clock recovery and GNSS tracking.
›
Robust statistics
statistics · low: Location and scale estimates (median, MAD, trimmed mean, Huber M-estimator) that stay correct when a minority of the data is garbage.
›
Hierarchical state machine
systems · low: Nest states so a substate inherits its parent's reactions and only overrides what differs, with ordered entry and exit actions along the path.
›
False sharing
concurrency · low: Independent variables written by different cores on one cache line force the line to bounce between cores; pad or regroup hot data to fix it.
›
Memory ordering
concurrency · low: What Relaxed, Acquire, Release and SeqCst atomics actually guarantee, what they cost on x86 and ARM, and which one each pattern needs.
›
Fencing tokens
distributed · low: A number that grows with every lock grant and is checked by the protected resource, so a paused ex-holder's late write is rejected.
›
+ 23 more primitives
System
Techniques · 4
Primitives · 39
smart-order-router
Clock synchronization
distributed · medium: Estimate a clock's offset from four timestamps, filter out queueing noise, and steer the clock smoothly; NTP gets about a millisecond, PTP with hardware timestamps under a microsecond.
›
Execution algorithms
finance · medium: TWAP, VWAP, POV and implementation-shortfall slicing of parent orders into child orders
Market impact models
finance · medium: Transaction-cost and market-impact estimation (square-root law, Almgren-Chriss) for routing and simulation
Order lifecycle state machine
finance · medium: Order states (new, partial fill, cancel/replace, rejected, expired) with strict transitions and idempotent events
Limit order book
finance · low: Per-symbol store of resting orders as FIFO queues per price level; array-indexed ticks plus intrusive lists give O(1) add, cancel and best-price lookup.
›
Sequenced multicast feed
networking · low: Exchange order-by-order data as fixed binary messages in sequenced UDP multicast packets
Hierarchical timing wheel
systems · low: Timers bucketed by expiry into wheels of slots, coarser wheels for far deadlines: O(1) insert and cancel for millions of timeouts.
›
Linear and logistic regression
machine-learning · low: Fit a weighted sum of features to a number (least squares) or a probability (logistic); the baseline every model must beat.
›
FIX protocol (session layer)
finance · low: Tag=value order-entry protocol over TCP with per-direction sequence numbers, heartbeats and resend so sessions survive disconnects without losing or duplicating orders.
›
Idempotency keys
finance · 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.
›
SPSC ring buffer
data-structures · low: Bounded wait-free queue for exactly one producer and one consumer thread, built from an array and two indices with acquire/release ordering.
›
Low-latency hot path
finance · low: Rules for microsecond trading paths: one pinned busy-polling thread per stage, no allocation, syscalls, locks or page faults after startup, kernel-bypass I/O, and measured tails.
›
Pre-trade risk checks
finance · low: Constant-time gate in front of order entry that rejects fat-finger, over-limit and runaway orders using worst-case exposure counted over open orders.
›
PID controller
robotics · low: Drive a measured value to a setpoint with three terms on the error: proportional, integral, derivative. The default feedback loop for motors, heaters, drones and gimbals.
›
Phase-locked loop (digital)
signal-processing · low: Feedback loop that locks a local oscillator to the phase and frequency of an input tone; the core of carrier recovery, clock recovery and GNSS tracking.
›
Robust statistics
statistics · low: Location and scale estimates (median, MAD, trimmed mean, Huber M-estimator) that stay correct when a minority of the data is garbage.
›
Hierarchical state machine
systems · low: Nest states so a substate inherits its parent's reactions and only overrides what differs, with ordered entry and exit actions along the path.
›
False sharing
concurrency · low: Independent variables written by different cores on one cache line force the line to bounce between cores; pad or regroup hot data to fix it.
›
Memory ordering
concurrency · low: What Relaxed, Acquire, Release and SeqCst atomics actually guarantee, what they cost on x86 and ARM, and which one each pattern needs.
›
Fencing tokens
distributed · low: A number that grows with every lock grant and is checked by the protected resource, so a paused ex-holder's late write is rejected.
›
Leases
distributed · 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.
›
Message sequence numbers
distributed · low: A per-stream counter on every message lets the receiver detect loss, duplicates and reordering, ack cheaply and resume after reconnect with "send from N".
›
Largest remainder rounding
finance · low: Splitting an amount into parts that sum exactly (largest remainder / Hamilton) for allocations, splits and prorations
Money representation
finance · low: Store money as integer minor units with an explicit currency exponent, compute in wider integers, and round once with a named rounding mode.
›
CPU caches and the memory hierarchy
hardware-os · low: Sizes, line widths and latencies of L1/L2/L3/DRAM on modern x86 and Apple M-series, and the data-layout rules that follow from them.
›
CRC32C checksums
hardware-os · low: The Castagnoli CRC-32 with dedicated instructions on x86 (SSE4.2) and ARMv8. It is the standard fast integrity check for storage blocks, logs and network frames.
›
fsync, O_DSYNC and O_DIRECT
hardware-os · low: What fsync, fdatasync, O_DSYNC, O_DIRECT and F_FULLFSYNC really guarantee on Linux and macOS, and the exact call sequences for crash-safe files.
›
Huge pages
hardware-os · low: 2 MB/1 GB pages to cut TLB misses; THP vs explicit hugetlbfs
Numa aware allocation
hardware-os · low: Allocate memory and pin threads on the local NUMA node; first-touch and interleave policies
SIMD programming
hardware-os · low: Process 4-16 lanes per instruction with AVX2, AVX-512 or NEON via Rust std::arch, with runtime dispatch and a portable fallback.
›
Loss functions
machine-learning · low: The scalar a model minimizes: cross-entropy for classes and tokens, MSE or Huber for values, each with a stable form and simple gradient.
›
Ebpf xdp
networking · low: EBPF programs at the XDP/tc hooks for in-kernel packet processing at line rate
Kernel-bypass networking
networking · low: User space (DPDK, AF_XDP) or an in-driver eBPF hook (XDP) handles packets straight from NIC rings, skipping sockets, for 10-40 Mpps per core.
›
Receive side scaling
networking · low: NIC hashing of flows to RX queues (RSS) and symmetric hashing for per-core processing
L-BFGS
numerics · low: Quasi-Newton minimizer that approximates the inverse Hessian from the last m gradient differences via the two-loop recursion; O(m·n) memory and work per step.
›
LU and Cholesky factorization
numerics · low: Factor A = PLU (any square matrix, partial pivoting) or A = LLᵀ (SPD) once in O(n³), then solve each right-hand side in O(n²).
›
PRNGs (PCG, xoshiro)
numerics · low: Small, fast, statistically strong non-cryptographic generators: PCG32 and xoshiro256**, with seeding, parallel streams and unbiased ranges.
›
Cryptographic hashes (SHA-2, BLAKE3)
security · low: Collision-resistant fingerprints of data; SHA-256 for interoperability, BLAKE3 for speed, HMAC/HKDF for keyed uses.
›
Write-ahead log
storage · low: Append each change to a checksummed sequential log and fsync it before touching data pages; the basis of crash durability in nearly every database.
›
Arena allocator
systems · low: Allocate by bumping a pointer through big chunks and free everything at once: a few instructions per allocation for objects sharing a lifetime.
›
Exponential backoff with jitter
systems · low: Retry after delays that grow geometrically and are randomized, so failed clients spread out instead of hammering a recovering service in synchronized waves.
›
Slab allocator
systems · low: Pre-carve pages into equal-size slots per size class with an in-place free list: O(1) alloc and free, no external fragmentation, cache-warm reuse.
›
Token bucket
systems · low: A bucket of up to b tokens refilled at rate r; requests spend tokens, enforcing an average rate while allowing bursts of b.
›
Copy for AI
Similar systems
Share the most building blocks with this one.
exchange
29 %
hft
27 %
market-data
22 %
energy-trading
22 %
oms
16 %