Golang Developer — High-Performance Discord Username Checker

# Golang Developer — High-Performance Discord Username Checker ## Project Overview I need a lightweight, high-performance Go application that checks a list of Discord usernames and reports their status as accurately and efficiently as the authorized endpoint allows. The application should prioritize speed, reliability, low resource consumption, and clean, maintainable code. The exact endpoint has not yet been confirmed. The developer must first identify a suitable, documented or explicitly authorized endpoint and verify its supported functionality, access requirements, and rate limits before implementing the checker. ## Core Requirements - **Language:** Modern Go (1.21 or newer). - **Concurrency:** Efficient goroutines, worker pools, and context-aware rate limiting. - **Input:** Read usernames from TXT or CSV files. - **Output:** Export results to JSON or CSV, with optional STDOUT output. - **HTTP performance:** Reuse connections, configure timeouts, and minimize unnecessary allocations. - **Proxy support:** Integrate my existing proxies, with configurable proxy settings and support for the protocols they provide. Document the required proxy format and authentication configuration. - **Error handling:** Handle network failures, timeouts, malformed responses, and HTTP 429 responses appropriately. - **Rate limiting:** Respect the endpoint's authorized request limits and any required backoff instructions. - **Result accuracy:** Distinguish confirmed available, confirmed taken, and inconclusive or failed checks. Do not classify errors as available usernames. - **Configuration:** Make concurrency, request rates, timeouts, and retry policies configurable without modifying the source code. ## Performance Requirements The target workload is up to 100,000 usernames on a VPS with 2 vCPUs and 4 GB RAM. The initial performance goal is to process this workload in under five minutes, provided the selected endpoint, authorization, and applicable rate limits permit it. The developer must benchmark actual throughput, total runtime, latency, error rate, and resource usage under documented test conditions. If the target cannot be achieved within the endpoint's permitted limits, explain the bottleneck and provide realistic performance estimates. ## Proxy Integration I already have proxies available. The application should allow me to configure them without hardcoding proxy credentials into the source code. Please document supported proxy protocols, configuration format, authentication requirements, connection handling, and how proxy failures are reported. Proxy support must not be used to circumvent platform rate limits or access restrictions. ## Code Quality and Deliverables - Complete Go source code. - Unit tests covering the main parsing, classification, configuration, and error-handling logic. - `go test` and `go vet` compatibility. - A concise README with build instructions, usage examples, configuration options, proxy setup, and benchmark methodology. - A ZIP archive or Git repository containing the source, tests, and documentation. Please propose a realistic testing and acceptance plan before implementation. ## Developer Qualifications Please provide evidence of experience with: - Advanced Go concurrency and networking. - High-throughput HTTP clients and connection reuse. - Proxy integration and reliable error handling. - Profiling, benchmarking, and performance optimization. - API integration and rate-limit-aware request processing. When applying, explain your proposed architecture, how you would validate the endpoint, and how you would measure performance on the specified VPS.