Rate limiting (token bucket / leaky bucket)
Related service Custom software engineering
DEFINITION
Caps how many calls a client / key / IP can make in a time window. Two main algorithms: token bucket refills at a fixed rate and each request spends a token · allows bursts up to capacity. Leaky bucket releases at a fixed rate and drops or queues overflow · smoother, less burst-friendly. In production you implement it on Redis (`INCR` + `EXPIRE` or Lua) or at the edge (Cloudflare, Vercel). Always include a `Retry-After` header on a 429.
- Firmware→
Low-level software that controls a hardware device · microcontroller, router, IoT sensor. Typical languages are C, Rust, MicroPython; OTA-updateability and signing are the critical parts.
- IoT OTA update→
Over-The-Air firmware update for IoT devices · signed image, staged rollout, rollback switch, telemetry. Lets you update a deployed fleet without physical access.
- HSM (Hardware Security Module)→
Specialised key-storage hardware · the private key never leaves the HSM, every cryptographic operation runs inside it. Foundation of banking and fintech integrations.
- OPC-UA→
Industrial communication protocol (IEC 62541) between PLCs, SCADA systems, and higher-level IT. The 2026 standard for manufacturing IT/OT integration.
- Modbus→
One of the oldest industrial protocols (since 1979) · PLCs, sensors, power meters communicate over it. TCP and RTU (serial) variants exist.
- CRDT (Conflict-free Replicated Data Type)→
Conflict-free Replicated Data Type. A data structure (counter, set, map, ordered text) that mathematically guarantees that if many peers edit it offline and sync in any order, the result is the same everywhere with no manual conflict resolution. Classic demo: the synced multiplayer cursor, where colleagues type in the same Figma or Notion document at the same time, characters do not overwrite each other, and cursors move live. Problem solved: last-write-wins and manual merge are weak primitives for collaborative editing, offline-first apps, and replicas running at the edge. Two schools: state-based (CvRDT, states can be merged) and operation-based (CmRDT, operations are commutative). In production: Yjs, Automerge, the Loro Rust library, plus Liveblocks and PartyKit as a service. The price: bigger payloads (operation logs) and you need garbage collection.
- 0126 Apr 2026OWASP LLM Top 10 v2 · what changed and what to ship→
- 0226 Apr 2026The CSP we ship · with notes on why each directive is there→
- 0322 Apr 2026Signed-firmware OTA pipeline · the 2026 default we ship→
- 0422 Apr 2026Agentic AI · the safe tool-use pattern we ship by default→
- 0522 Apr 2026Solana smart contract gotchas · what bites every Anchor dev in 2026→
- 0622 Apr 2026Multi-tenant SaaS on Postgres · the RLS-first playbook→
- 0722 Apr 2026EIP-712 meta-transactions · gasless UX without compromising security→
- 0820 Apr 2026NIS2 for SaaS: minimum checklist for 2026→