Networking
How requests find their way in.
11 concepts · 34 technologies · 2 comparisons · 5 real stacks
Concepts
Start with Network protocols- Network protocols9 technologiesThe agreed rules that move bytes between machines, stacked in layers: IP finds the host, a transport such as TCP or UDP finds the program, TLS keeps it private, and HTTP or FTP says what the bytes mean.
- Load balancers4 technologiesSpreads incoming traffic across healthy servers.
- Load-balancing algorithmsThe rule a load balancer uses to pick which healthy server gets the next request or connection.
- CDNs3 technologiesCopies of your content cached close to your users.
- API gateways2 technologiesThe front door for your APIs: auth, limits and routing in one place.
- DNS3 technologiesThe internet’s phone book: turns names into addresses.
- Virtual private clouds1 technologyYour own private, isolated network inside the cloud.
- Service discovery & mesh3 technologiesHow services find each other’s healthy instances, and a layer of proxies that secures and steers the calls between them.
- Remote procedure calls4 technologiesCall a function on another machine as if it were local: a shared interface, generated stubs and a compact encoding.
- Web APIs2 technologiesA service exposed over plain HTTP, as resources with URLs (REST) or as one typed graph (GraphQL), so any browser, app or partner can call it.
- API frameworks6 technologiesLibraries that turn ordinary functions into HTTP or GraphQL endpoints: they route each request, parse and check its input, serialize the result and describe the API for docs and generated clients.
Technologies
Grouped by the concept each one mainly implements
Commonly confused
See it in a real stack
Architectures that use networking conceptsServerless web app on AWSCloudFront serves the site from S3 and sends API calls through API Gateway to Lambda functions backed by DynamoDB.Amazon CloudFrontAmazon S3Amazon API GatewayAWS LambdaAmazon DynamoDBWeb app on KubernetesA load balancer spreads requests over app pods on Kubernetes, which check Redis before going to PostgreSQL.AWS Application Load BalancerKubernetesRedisPostgreSQLCQRS with a static read sideCommands update PostgreSQL; a Lambda projector rewrites the affected JSON views in S3, and CloudFront serves every read without touching a database.Amazon API GatewayAWS LambdaPostgreSQLAmazon SQSAmazon S3Amazon CloudFrontCode sandboxes for AI agentsAn agent’s code runs in a fresh Firecracker microVM per task, isolated by its own kernel, with outputs saved to S3.FirecrackerAmazon S3GraphQL API in PythonUvicorn runs a FastAPI app that mounts Strawberry’s GraphQL router; graphql-core parses, validates and executes each query, and resolvers load rows through SQLAlchemy from PostgreSQL.FastAPIStrawberry GraphQLGraphQL-corePydanticSQLAlchemyPostgreSQL
Worth exploring
All resources →Slides· September 2025How and Why Datadog moved from cloud-managed to self-managed PostgresNick Canzoneri, Datadog, at PGConf NYC 2025Slides from a talk on why a company running hundreds of Postgres clusters across several clouds left managed services for its own Postgres platform on Kubernetes, how it moved a whole region, and what got better and worse. The stack is Patroni (with ZooKeeper for leader election), WAL-G backups, a Helm chart rather than an operator, and Temporal workflows for automation. Useful before you weigh RDS-style convenience against running Postgres yourself.
Article· February 2021Alternative to AWS lambda serverless concept in Kubernetes?Stack Overflow question by ajsgA team running everything on Kubernetes asks how to get Lambda-style, per-request scaling for loading AI models from S3. The 2021 answers name Knative, KFServing (now KServe) and Kubeless (since archived), which makes it a quick snapshot of the options rather than an up-to-date guide.