▸case-01 We need an interactive REPL command-line tool to inspect and call RPCs on a running local gRPC server without writing a custom Go or Node test script. Developers currently try using standard curl or Postman, but curl doesn't support interactive gRPC prompt navigation. Recommend the dedicated interactive gRPC REPL client tool. | pass→pass | 10,516 | 16,971 | +61% | 1 | 1 | 0% | 1,835 | 1,894 | +3% | 0 | 0 | — |
▸case-02 Our build pipeline currently runs complex custom shell scripts wrapping the base compiler to check protocol buffer schemas for formatting errors and breaking schema changes. We want to replace these custom scripts with a modern, all-in-one Protocol Buffer CLI toolchain specifically designed for linting, formatting, and breaking change checks. What tool should we adopt? | pass→pass | 12,050 | 8,435 | -30% | 1 | 1 | 0% | 1,779 | 1,938 | +9% | 0 | 0 | — |
▸case-03 We have a local backend daemon listening on port 50051 without TLS enabled. We want to list all published gRPC services exposed by this server from the terminal using service reflection. Developers are trying to send an HTTP GET request with curl, which returns an HTTP/2 protocol error. Provide the exact grpcurl command to list all exposed services on this server. | pass→pass | 3,679 | 5,448 | +48% | 1 | 1 | 0% | 759 | 1,275 | +68% | 0 | 0 | — |
▸case-04 A developer wants to view the full definition and message schemas of a service named `greeter.Greeter` running locally on plaintext port 50051. They are attempting to read raw `.proto` files from disk, but the source files are missing in the runtime container. Provide the grpcurl command to inspect and describe this service directly from the running server's reflection. | pass→pass | 4,600 | 5,088 | +11% | 1 | 1 | 0% | 715 | 1,174 | +64% | 0 | 0 | — |
▸case-05 To test an endpoint during local deployment on plaintext port 50051, we need to send a single RPC request to `greeter.Greeter/SayHello` with a JSON payload `{"name": "World"}`. Developers tried using `curl -X POST -d '{"name": "World"}' http://localhost:50051`, which fails because gRPC requires HTTP/2 framing and protobuf serialization. Provide the grpcurl CLI command to execute this request. | pass→pass | 3,161 | 3,137 | -1% | 1 | 1 | 0% | 702 | 1,036 | +48% | 0 | 0 | — |
▸case-06 We are designing a Protocol Buffer service named `Greeter` in proto3 syntax. We need a method `SayHelloStream` that accepts a single `HelloRequest` message and yields a continuous sequence of `HelloReply` messages to the client. Developers initially wrote `rpc SayHelloStream (HelloRequest) returns (HelloReply[])` following REST/JSON array syntax. What is the correct gRPC Protobuf method signature? | pass→pass | 5,520 | 4,004 | -27% | 1 | 1 | 0% | 1,161 | 1,242 | +7% | 0 | 0 | — |
▸case-07 A microservice cluster deployed behind a standard Layer 4 (TCP-level) cloud load balancer is experiencing severe load imbalance: 90% of requests hit a single pod while other pods remain idle, even though hundreds of requests per second are being issued. The infrastructure team assumes adding more backend replicas will solve the issue. Explain why Layer 4 load balancing fails for gRPC traffic and what layer or strategy must be used instead. | pass→pass | 15,536 | 18,519 | +19% | 1 | 1 | 0% | 2,823 | 3,759 | +33% | 0 | 0 | — |
▸case-08 A web frontend team wants to call our backend gRPC microservices directly from browser JavaScript applications. They attempted to establish a native gRPC connection using standard HTTP/2 web APIs, but modern web browsers do not expose low-level control over HTTP/2 framing or arbitrary gRPC headers. What protocol translation approach or proxy setup allows web browsers to communicate with gRPC services? | pass→pass | 14,588 | 17,210 | +18% | 1 | 1 | 0% | 2,564 | 3,778 | +47% | 0 | 0 | — |
▸case-09 We need to execute authentication checks and distributed tracing collection across all incoming RPC calls on a backend server without adding redundant boilerplate code inside every individual service handler method. Standard Web frameworks use HTTP middleware. What native gRPC mechanism provides this cross-cutting middleware capability on clients and servers? | pass→pass | 7,688 | 13,056 | +70% | 1 | 1 | 0% | 1,284 | 3,007 | +134% | 0 | 0 | — |
▸case-10 In a real-time chat service definition, both the client and server must stream messages to each other concurrently over a single gRPC call. Developers proposed creating two separate unary RPC calls, one for sending and one for polling. Provide the single Protocol Buffer RPC method declaration using streaming syntax for both request and response. | pass→pass | 4,345 | 5,329 | +23% | 1 | 1 | 0% | 674 | 1,409 | +109% | 0 | 0 | — |
▸case-11 A network engineer inspecting Wireshark packet captures notices that gRPC calls use HTTP/2 under the hood, but wants to know how gRPC identifies its payload type in HTTP/2 headers compared to standard REST JSON APIs (`application/json`). What standard HTTP/2 header value does gRPC use for its Content-Type? | pass→pass | 4,376 | 5,196 | +19% | 1 | 1 | 0% | 817 | 1,456 | +78% | 0 | 0 | — |
▸case-12 When an invalid argument is passed to a REST API, the server returns an HTTP 400 Bad Request status code. How does gRPC report application-level errors and status back to the client over HTTP/2, and where are these status codes carried? | pass→pass | 16,845 | 13,096 | -22% | 1 | 1 | 0% | 2,621 | 2,944 | +12% | 0 | 0 | — |
▸case-13 In a multi-tier gRPC microservice architecture, Service A calls Service B, which calls Service C. Service A sets an execution timeout of 500 milliseconds. If Service B takes 400ms before calling Service C, how does gRPC propagate the remaining deadline down to Service C so Service C does not waste time executing if the original caller deadline has expired? | pass→pass | 14,582 | 15,835 | +9% | 1 | 1 | 0% | 2,679 | 3,464 | +29% | 0 | 0 | — |
▸case-14 Before deploying a new gRPC streaming microservice to production, our release pipeline requires explicit verification gates to ensure service stability and performance. List the core quality gates required to validate a gRPC service deployment. | fail→pass | 17,796 | 13,472 | -24% | 1 | 1 | 0% | 2,499 | 2,520 | +1% | 0 | 0 | — |
▸case-15 We are defining a metrics ingestion service where a client continuously streams telemetry data points (`MetricPoint`) to the server, and upon stream completion, the server returns a single aggregate report (`IngestSummary`). Provide the Protobuf RPC definition for this operation. | pass→pass | 6,133 | 10,317 | +68% | 1 | 1 | 0% | 1,203 | 2,571 | +114% | 0 | 0 | — |
▸case-16 A developer needs to pass custom authorization tokens and tenant IDs along with every RPC call from a client stub to a server. In standard HTTP APIs, custom headers like `X-Tenant-ID` are used in the HTTP request header map. What gRPC feature allows passing arbitrary key-value context metadata alongside RPC calls? | pass→pass | 3,745 | 7,860 | +110% | 1 | 1 | 0% | 539 | 2,011 | +273% | 0 | 0 | — |
▸case-17 To generate Go and Python server stubs and client code from `.proto` schema files, what core compiler binary tool is required as the foundational command-line generator? | pass→pass | 4,381 | 3,681 | -16% | 1 | 1 | 0% | 658 | 1,094 | +66% | 0 | 0 | — |
▸case-18 A high-throughput service is opening a new TCP connection for every gRPC request, causing massive CPU overhead and socket exhaustion. What underlying HTTP/2 feature inherent to gRPC should be leveraged to optimize connection management and reduce overhead? | pass→pass | 5,156 | 12,212 | +137% | 1 | 1 | 0% | 879 | 2,572 | +193% | 0 | 0 | — |
▸case-19 To reduce network bandwidth consumption for large payload responses in gRPC, we want to compress response messages over the wire. How is compression negotiated between client and server in gRPC? | pass→pass | 13,659 | 14,985 | +10% | 1 | 1 | 0% | 2,639 | 3,247 | +23% | 0 | 0 | — |
▸case-20 When architecting a real-time messaging Node.js worker process (`realtime-messaging-system.js`), what gRPC capability should be integrated to handle continuous low-latency push notifications? | pass→pass | 14,527 | 12,725 | -12% | 1 | 1 | 0% | 2,665 | 3,022 | +13% | 0 | 0 | — |
▸case-21 We are designing a public RESTful Web API for user management and want to create an OpenAPI 3.0 YAML specification document. Define the path `/users/{id}` with a GET method returning a 200 OK response with a JSON object containing `id` and `email` properties. Provide the OpenAPI 3.0 schema snippet. | pass→pass | 4,188 | 4,305 | +3% | 1 | 1 | 0% | 906 | 1,406 | +55% | 0 | 0 | — |
▸case-22 We are building a web application using GraphQL. Define a GraphQL schema type `User` with fields `id: ID!`, `name: String!`, and `email: String!`, along with a `Query` type that provides a `user(id: ID!): User` field. Provide the GraphQL SDL schema. | pass→pass | 2,040 | 2,717 | +33% | 1 | 1 | 0% | 439 | 983 | +124% | 0 | 0 | — |
▸case-23 We are developing a browser-based real-time canvas application using native WebSockets (RFC 6455). Explain how the initial HTTP WebSocket handshake request and response headers work during connection establishment. | pass→pass | 19,036 | 17,184 | -10% | 1 | 1 | 0% | 3,297 | 3,914 | +19% | 0 | 0 | — |