topic / backend-engineering

Backend Engineering

Build request handlers that remain understandable under load and failure.

Connect HTTP and API design to authentication, data access, transactions, queues, caching, timeouts, retries, rate limits, and reliable service behavior.

1 article · 1 video · 1 trace · 3 request flows · 1 interview · 7 total

Articles

backend engineeringSep 25, 2026

Retries Need an Operation Contract

Design timeouts, retries, idempotency keys, and server-side state so a lost response does not silently duplicate an operation.

7 min readRead

Request Flows

request flow · 5 stagesNetwork Layers in a RequestVisualize the four network layers (application, transport, network, link, physical) and how each adds a header as a request travels to a server.request flow · 5 stagesRate Limiting with a Token BucketVisualize how a token bucket limits request rate, handles bursts, and enforces a steady throughput ceiling.request flow · 5 stagesA Safe Retry Reuses One Logical Request KeySee how authentication, key lookup, atomic work, stored outcomes, and retry replay prevent duplicate create operations.

Videos

In production

backend engineeringSep 25, 2026

Designing a Retry-Safe API

A planned scenario shows how a lost response creates uncertainty and how idempotency keys define one logical operation.

Details

Traces

trace 01 · serverTrace a Retried Create Request With an Idempotency KeyFollow a POST request from key validation through durable result storage so a lost response does not create a second resource.

Interviews

medium · t2How Do You Make a POST Request Safe to Retry?A backend prompt about uncertain outcomes, idempotency keys, atomic state changes, timeouts, and downstream side effects.

Explore adjacent

networking databases software architecture system design api semantics and versioning identity and sessions retries and backpressure

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