Open Stock Exchange (Matching Engine) →Open Instagram Feed →

Stock Exchange (Matching Engine) vs Instagram Feed

Stock Exchange (Matching Engine)

Deterministic price-time-priority matching, a sequencer for total order and replay, microsecond latency, and separate market-data and reporting paths.

Components (13)

Trader / Algo
Client Gateway
Order Manager
Risk Check
Wallet
Sequencer
Matching Engine
Order Book
Market Data Publisher
Market Data Feed
Reporter
Orders & Executions DB
Clearing & Settlement

Headline numbers

Per-symbol matcher load (hot symbols)~500K orders/sec for AAPL/SPY
Sequencer/event-store throughput~50B events/day → ~600K/sec sustained, ~10M/sec peak
Market data subscribers~50,000

Instagram Feed

Fan-out on write vs read, ranking, CDN.

Components (10)

Mobile Client
CDN
API Gateway
Feed Service
Post Service
Kafka
Fan-out Worker
Redis
Postgres
S3

Headline numbers

Posts / sec (avg)~3,000/sec
Feed read QPS~58,000/sec
Fan-out writes / sec~600,000/sec

Key differences

Only in Stock Exchange (Matching Engine)

Market Data Feed

In both

Client
Api Gateway
Service
Queue
Cache
Database

Only in Instagram Feed

Flow shape

Stock Exchange (Matching Engine) flows

Order crosses a resting order11 steps
Publish market data2 steps
Reporting (off the hot path)2 steps
⚠ Matching engine for AAPL crashes4 steps

Instagram Feed flows

Post a photo (fan-out on write)7 steps
Open feed (precomputed timeline)5 steps
⚠ Fan-out Worker is down7 steps
⚠ Timeline cache flushed (Redis restart)4 steps