HTTP
Requests, responses, caching and CORS.
HTTP is taught here in 13 lessons, running from HTTP methods through to Debugging HTTP: tools, logs and observability. Each lesson takes one topic, shows the working code, and links onward to the next, so the course can be read straight through in order.
| Track | Back-end Development |
| Lessons | 13 |
| Level | Beginner to intermediate |
| Reading time | about 3 hours |
| Prerequisites | Helpful, but not required: Java |
Lessons
- HTTP methodsGET, POST, PUT, PATCH and DELETE — what each promises about safety, idempotency, and when to use it.
- HTTP status codesThe codes that actually matter in production — and the ones applications routinely get wrong.
- HTTP headersContent negotiation, auth, compression and security headers — the metadata that controls real behaviour.
- Caching and conditional requestsCache-Control in plain language, ETags versus Last-Modified, and revalidation with 304 responses.
- CORS explainedWhy the browser blocks cross-origin reads, how preflight works, and the headers that fix it properly.
- HTTPS and TLSWhat TLS actually protects, how certificates get validated, renewal automation, and mixed content traps.
- Message anatomy and framingRequest and response structure, start line and headers, Content-Length versus chunked transfer, trailers, and how HTTP/1.1, HTTP/2 and HTTP/3 differ on the wire.
- Cookies, sessions and stateSet-Cookie attributes, Domain, Path, Secure, HttpOnly and SameSite, session identifiers, third-party cookie restrictions, and storage alternatives.
- Authentication on the wireBasic and Digest, Bearer tokens and JWT structure, API keys, OAuth 2.1 flows and scopes, mutual TLS, and how WWW-Authenticate drives the flow.
- Compression, content negotiation and media typesAccept and Accept-Encoding with quality values, gzip, Brotli and zstd, charset handling, multipart uploads, and byte-range requests.
- Proxies, load balancers and connection managementForwarded and X-Forwarded headers, keep-alive and connection pooling, timeouts and retries, idempotency keys, and how CDNs and reverse proxies rewrite traffic.
- HTTP API design in practiceApplying method semantics, pagination strategies, ETags in APIs, problem-detail error bodies, versioning, webhooks and delivery guarantees.
- Debugging HTTP: tools, logs and observabilitycurl and API clients, browser network panel analysis, HAR capture, server access logs, tracing and correlation headers, Server-Timing, and a catalogue of common failure signatures.
More in Back-end Development
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FAQ
How long does the HTTP course take?
It has 13 lessons, about 3 hours of reading. Expect roughly twice that if you type out and run every example.
Do I need prior experience for HTTP?
Not strictly. It helps to have read Java first, because some lessons build on it, but every lesson explains its own assumptions.
What should I read after HTTP?
Continue with Go (13 lessons), the next course in Back-end Development.
Last refreshed 2026-09-18.