Complete Projects
Build tested, end-to-end projects from first file to deployment.
157 published
Build an Alerting Rule Evaluator
Alerting Rule Evaluator — a complete walkthrough of alert evaluation, covering rule loader, metric reader, condition evaluator, and testing.
Build a Tamper-Proof Audit Trail
Tamper-Proof Audit Trail — a complete walkthrough of audit logging, covering event appender, hash chain, merkle checkpoint, and testing.
Build a Backpressure Queue Service
Backpressure Queue Service — a complete walkthrough of flow control, covering bounded queue, watermark monitor, producer signal, and testing.
Build a Benchmark Runner CLI
Benchmark Runner CLI — a complete walkthrough of performance benchmarking, covering benchmark loader, warmup runner, sample collector, and testing.
Build a Certificate Manager
Certificate Manager — a complete walkthrough of x.509 certificate lifecycle, covering acme client, order tracker, challenge solver, and testing.
Build a Change Data Capture Pipeline
Change Data Capture Pipeline — a complete walkthrough of change data capture, covering log tail reader, change decoder, schema projector, and testing.
Build a Columnar Query Engine
Columnar Query Engine — a complete walkthrough of analytical query processing, covering column reader, predicate pushdown, vectorized aggregate, and testing.
Build a Config Validator CLI
Config Validator CLI — a complete walkthrough of configuration validation, covering config loader, schema compiler, validator, and testing.
Build a Connection Pool Manager
Connection Pool Manager — a complete walkthrough of database connection pooling, covering idle queue, health probe, acquire timeout, and testing.
Build a CSV Streaming Parser
CSV Streaming Parser — a complete walkthrough of streaming csv parsing, covering byte chunker, line splitter, field parser, and testing.
Build a Data Diff CLI
Data Diff CLI — a complete walkthrough of data comparison, covering snapshot reader, key indexer, row comparator, and testing.
Build a Data Quality Validator
Data Quality Validator — a complete walkthrough of data quality enforcement, covering rule engine, column profiler, uniqueness checker, and testing.
Build a Dependency Graph CLI
Dependency Graph CLI — a complete walkthrough of dependency analysis, covering manifest reader, graph builder, cycle detector, and testing.
Build a Distributed Lock Service
Distributed Lock Service — a complete walkthrough of mutual exclusion, covering lock acquirer, fence issuer, lease renewer, and testing.
Build a Distributed Tracing Collector
Distributed Tracing Collector — a complete walkthrough of trace collection, covering span ingest, trace assembler, span store, and testing.
Build a DNS Resolver Cache
DNS Resolver Cache — a complete walkthrough of dns resolution, covering record cache, ttl scheduler, negative cache, and testing.
Build a Document Version Store
Document Version Store — a complete walkthrough of document versioning, covering content-addressed blob, revision tree, diff serializer, and testing.
Build an Email Template Renderer
Email Template Renderer — a complete walkthrough of email rendering, covering template loader, variable binder, css inliner, and testing.
Build an ETL Pipeline Orchestrator
ETL Pipeline Orchestrator — a complete walkthrough of batch data processing, covering stage graph, task scheduler, retry policy, and testing.
Build an External Batch Sort
External Batch Sort — a complete walkthrough of external sorting, covering chunk reader, in-memory sorter, run writer, and testing.
Build a Feature Flag Service
Feature Flag Service — a complete walkthrough of feature toggling, covering flag store, rule evaluator, rollout bucket, and testing.
Build a Graph Traversal Service
Graph Traversal Service — a complete walkthrough of graph traversal, covering adjacency store, bfs engine, dijkstra engine, and testing.
Build a gRPC Service Mesh Client
gRPC Service Mesh Client — a complete walkthrough of inter-service rpc, covering channel resolver, load balancer, retry policy, and testing.
Build a Health Check Orchestrator
Health Check Orchestrator — a complete walkthrough of composite health checking, covering check registry, parallel runner, timeout guard, and testing.
Build an HTTP Cache Layer
HTTP Cache Layer — a complete walkthrough of http response caching, covering key normalizer, freshness checker, validation revalidate, and testing.
Build an Idempotency Key Store
Idempotency Key Store — a complete walkthrough of request deduplication, covering key store, result cache, in-flight tracker, and testing.
Build an Image Resize Pipeline
Image Resize Pipeline — a complete walkthrough of image processing, covering decode pool, resize worker, format encoder, and testing.
Build an Input Sanitizer Service
Input Sanitizer Service — a complete walkthrough of input validation and normalization, covering schema validator, html stripper, encoding normalizer, and testing.
Build an Inverted Index Search Engine
Inverted Index Search Engine — a complete walkthrough of full-text search, covering tokenizer pipeline, posting list writer, tf-idf ranker, and testing.
Build a Distributed Job Scheduler
Distributed Job Scheduler — a complete walkthrough of scheduled job execution, covering job queue, time trigger, lock acquirer, and testing.
Build a JSON Schema Inferer
JSON Schema Inferer — a complete walkthrough of schema inference, covering sample reader, type inferer, structure merger, and testing.
Build a Raft Leader Election
Raft Leader Election — a complete walkthrough of consensus leadership, covering term tracker, vote requester, heartbeat sender, and testing.
Build a Load Balancer with Health Checks
Load Balancer with Health Checks — a complete walkthrough of traffic distribution, covering upstream pool, active health probe, passive failure counter, and testing.
Build a Structured Log Pipeline
Structured Log Pipeline — a complete walkthrough of log ingestion, covering ingest buffer, enrichment stage, route table, and testing.
Build an LRU Cache with TTL
LRU Cache with TTL — a complete walkthrough of bounded caching, covering hash map, recency list, ttl wheel, and testing.
Build a Merkle Tree Sync
Merkle Tree Sync — a complete walkthrough of merkle tree synchronization, covering leaf hasher, tree builder, root comparer, and testing.
Build a Pull-Based Metrics Aggregator
Pull-Based Metrics Aggregator — a complete walkthrough of metrics collection, covering scrape scheduler, target manager, sample parser, and testing.
Build a Minimal MQTT Broker
Minimal MQTT Broker — a complete walkthrough of publish-subscribe messaging, covering topic trie, subscription matcher, retained store, and testing.
Build a Notification Fanout Service
Notification Fanout Service — a complete walkthrough of notification delivery, covering event receiver, channel router, delivery queue, and testing.
Build an OAuth2 Authorization Server
OAuth2 Authorization Server — a complete walkthrough of oauth2 delegation, covering authorization endpoint, token issuer, consent screen, and testing.
Build a Sampling Profiler Analyzer
Sampling Profiler Analyzer — a complete walkthrough of profile analysis, covering sample ingest, stack merger, flame builder, and testing.
Build a Sliding Window Rate Limiter
Sliding Window Rate Limiter — a complete walkthrough of precise rate limiting, covering window counter, timestamp trim, boundary check, and testing.
Build a Release Notes CLI
Release Notes CLI — a complete walkthrough of release note generation, covering commit reader, conventional parser, group sorter, and testing.
Build a Resumable Upload Service
Resumable Upload Service — a complete walkthrough of large file upload, covering upload session, chunk receiver, offset tracker, and testing.
Build a TLS Reverse Proxy
TLS Reverse Proxy — a complete walkthrough of tls termination, covering tls context, sni router, cert loader, and testing.
Build a Scaffold Codegen CLI
Scaffold Codegen CLI — a complete walkthrough of project scaffolding, covering template loader, variable prompt, file renderer, and testing.
Build a Schema Migration CLI
Schema Migration CLI — a complete walkthrough of database schema migration, covering migration loader, version tracker, up applier, and testing.
Build a Schema Registry Service
Schema Registry Service — a complete walkthrough of schema evolution governance, covering schema parser, compatibility checker, version store, and testing.
Build a Secrets Rotation Service
Secrets Rotation Service — a complete walkthrough of secret lifecycle, covering secret store, rotation schedule, dual-publish window, and testing.
Build a Service Discovery Registry
Service Discovery Registry — a complete walkthrough of service discovery, covering instance registry, heartbeat tracker, ttl evictor, and testing.
Build a Skip List Index
Skip List Index — a complete walkthrough of ordered in-memory indexing, covering level generator, node inserter, search path, and testing.
Build a Snapshot Backup Service
Snapshot Backup Service — a complete walkthrough of point-in-time backup, covering copy-on-write fork, chunk uploader, manifest writer, and testing.
Build a Stream Window Aggregator
Stream Window Aggregator — a complete walkthrough of stream processing, covering event ingest, window manager, aggregate function, and testing.
Build a Time-Series Database Aggregator
Time-Series Database Aggregator — a complete walkthrough of time-series data aggregation, covering downsample buckets, retention policy, compression encoder, and testing.
Build a Distributed Token Bucket
Distributed Token Bucket — a complete walkthrough of distributed rate limiting, covering local bucket, remote sync, refill scheduler, and testing.
Build a Vector Embedding Store
Vector Embedding Store — a complete walkthrough of vector similarity search, covering hnsw index, distance metric, insert pipeline, and testing.
Build a WAF Rule Engine
WAF Rule Engine — a complete walkthrough of web application firewalling, covering rule loader, pattern matcher, score accumulator, and testing.
Build a WAL Replication Manager
WAL Replication Manager — a complete walkthrough of write-ahead log replication, covering log appender, follower shipper, checkpoint store, and testing.
Build a Webhook Delivery with Retry
Webhook Delivery with Retry — a complete walkthrough of webhook delivery, covering delivery queue, backoff scheduler, attempt runner, and testing.
Build a WebSocket Presence Server
WebSocket Presence Server — a complete walkthrough of real-time presence, covering connection registry, room router, presence tracker, and testing.
Build an Async Job Priority Queue
A multi-tier async job queue with priority lanes, fair scheduling across lanes, delayed dispatch, and per-worker concurrency control.
Build a Binary Diff Patcher
A binary diff tool that computes a compact patch between two byte sequences using a rolling hash and applies it to reconstruct the target without the source at apply time.
Build a Bloom Filter Cache Guard
A Bloom filter that sits in front of a cache to reject absent-key lookups cheaply, with counting removal, auto-scaling bit array, and a measured false-positive rate.
Build a Circuit Breaker Proxy
A proxy that wraps an upstream with a circuit breaker, tripping open on error-rate thresholds, half-opening to probe recovery, and closing when probes succeed.
Build a Consistent Hash Router
A consistent hash ring that maps keys to nodes with minimal remapping on node add or remove, using virtual nodes for balance and a sorted ring for O(log n) lookup.
Build a Cookie Session Store
A server-side session store that issues signed, http-only cookies, rotates the session id on privilege change, and expires idle sessions with a background sweeper.
Build a CRDT Text Collab
A last-write-wins text CRDT that supports concurrent insert and delete from multiple peers, converges without coordination, and serializes ops for transport.
Build a Dedup Store on LSM
A log-structured merge store with content-addressed chunks that deduplicates writes by hash, compacts SSTables in the background, and serves point lookups via an index.
Build a Delayed Job Scheduler
A scheduler that enqueues jobs for future execution using a hierarchical timing wheel, with cancellation, retry on failure, and a persistence layer for crash recovery.
Build a Distributed ID Generator
A snowflake-style 64-bit ID generator that produces globally unique, time-ordered IDs without coordination, using a machine id and a sequence counter.
Build a Local Event Bus
An in-process event bus with typed channels, subscriber ordering, error isolation per handler, and a replay buffer for late subscribers.
Build a File Watch Pipeline
A pipeline that watches a directory for changes, debounces rapid saves, runs a transform on each changed file, and emits results with a manifest of what was processed.
Build a Gossip Cluster Discovery
A gossip protocol for cluster member discovery where each node periodically exchanges its member list with a random peer, converging to a consistent view without a central registry.
Build a Heap Metrics Aggregator
A streaming metrics aggregator that maintains a per-percentile sketch on a heap, answering quantile queries in O(1) without storing every sample.
Build an Idempotency Key Middleware
A middleware that caches responses by an idempotency key header, returning the cached response for duplicate requests and storing in-flight results to prevent double execution.
Build a KV Store with WAL
A persistent key-value store that writes a write-ahead log for durability, an in-memory index for fast lookups, and checkpoints to bound recovery time.
Build a Leader Election via Bully
A bully algorithm leader election where the highest-id live node becomes leader, detecting coordinator failure and starting an election with O(n^2) messages in the worst case.
Build a Log-Structured Store
A log-structured store that appends every write to a segment, indexes keys to segment offsets, and compacts segments in the background to reclaim space from superseded records.
Build an MVCC Snapshot Store
A multi-version concurrency control store that gives each transaction a consistent snapshot, writes create new versions, and garbage collection reclaims versions invisible to all live snapshots.
Build a Configurable API Gateway
A complete API gateway that routes by path prefix, injects auth headers, applies per-route rate limits and timeouts, and logs structured access events.
Build an API Key Management Service
A complete API key service: hashed key storage, prefix lookup, scopes, expiry, rotation with overlap, usage metering, and revocation tests.
Build a Tamper-Evident Audit Log Service
A complete audit log service: append-only records, per-stream hash chaining, periodic checkpoints, verification endpoint, and tamper-detection tests.
Build a Contact Form Backend with Spam Protection
A complete contact form backend: validation, honeypot and timing heuristics, rate limiting, email delivery, and spam-rejection tests.
Build a Content Moderation Service
A complete moderation service: pre-publish screening, rule and model scoring, review queue, appeals, and false-positive handling tests.
Build a CSV Import Validation Pipeline
A complete CSV import pipeline: streaming parse, row-level validation, error collection, transactional commit, and partial-success tests.
Build an Asynchronous Data Export Service
A complete export service: export jobs, streaming CSV generation, private signed downloads, expiry, progress reporting, and large-dataset tests.
Build a Database Migration Runner
A complete migration runner: ordered versioned files, a checksum ledger, transactional apply, rollback scripts, and drift-detection tests.
Build a Leased Distributed Task Scheduler
A complete scheduler that claims due tasks with leases, handles retries and dead letters, and survives worker crashes without double execution.
Build an Outbound Email Queue Service
A complete email queue: job persistence, provider rate limiting, bounce webhook processing, suppression lists, and retry-only-transient tests.
Build an Event-Sourced Account Ledger
A complete event-sourced ledger: immutable events, aggregate replay, optimistic concurrency, projections, and a verified balance invariant.
Build a Feature Flag Service with Targeting Rules
A complete feature flag service: typed flags, percentage rollout, user targeting, kill switches, cached evaluation, and deterministic bucketing tests.
Build a Full-Text Search API on PostgreSQL
A complete full-text search API using PostgreSQL tsvector, GIN indexes, weighted ranking, highlight snippets, and query-parsing tests.
Build a Geocoding Proxy with Cache and Rate Limiting
A complete geocoding proxy: provider abstraction, negative caching, per-key rate limits, quota metering, and cache-behavior tests.
Build a GraphQL Blog API with DataLoader
A complete GraphQL blog API with schema, resolvers, cursor pagination, per-request DataLoader batching, and N+1 regression tests.
Build GraphQL Subscriptions over WebSockets
A complete GraphQL subscription service: WebSocket transport, auth on connect, pub-sub integration, backpressure, and delivery tests.
Build an Image CDN Proxy with On-the-Fly Resizing
A complete image CDN proxy: signed resize URLs, cache headers, conditional requests, format negotiation, and cache-key tests.
Build a JWT Auth Service with Refresh Rotation
A complete JWT auth service: short-lived access tokens, rotating refresh tokens with reuse detection, key rotation, and revocation tests.
Build a Local-First Notes Sync Server
A complete sync server for local-first notes: version vectors, conflict detection, merge strategy, incremental sync, and divergence tests.
Build a Log Search Service over OpenSearch
A complete log search service: structured ingest, index templates with rollover, time-range queries, aggregations, and retention tests.
Build a Prometheus Metrics Exporter Service
A complete Prometheus exporter: counters, gauges, histograms, label discipline, a pull endpoint, and tests that assert metric names and buckets.
Build a MongoDB REST API with Cursor Pagination
A complete MongoDB REST API: schema validation, indexed queries, cursor pagination, optimistic updates, and integration tests against a real database.
Build a Multi-Tenant API with Row-Level Isolation
A complete multi-tenant API: tenant resolution, row-level security, per-tenant connections, quota enforcement, and cross-tenant leak tests.
Build a Multi-Channel Notification Dispatcher
A complete notification dispatcher: templated messages, per-channel adapters, user preferences, deduplication, delivery tracking, and retry tests.
Implement an OAuth2 Authorization Code Server
A complete OAuth2 authorization-code server with PKCE, consent, scoped access tokens, refresh rotation, and revocation, plus tests.
Build an Idempotent Payment Webhook Processor
A complete payment webhook processor: signature verification, raw-body capture, idempotency keys, ordered state updates, and replay tests.
Build a PDF Invoice Generator
A complete PDF invoice generator: data model, computed totals, embedded fonts, PDF output, and tests that assert amounts and page count.
Add a Redis Cache-Aside Layer to a REST API
A complete cache-aside layer for a REST API: key design, TTL and jitter, stampede protection, tag-based invalidation, and cache-hit tests.
Build a Headless Screenshot Service
A complete screenshot service: browser pool, render timeouts, viewport presets, full-page capture, safe URL handling, and output tests.
Build a Server-Side Session Store Service
A complete server-side session store: opaque session ids, Redis-backed records, sliding expiry, rotation on privilege change, and fixation tests.
Build a Slug and Redirect Service
A complete slug and redirect service: unique slug generation, reserved-word handling, 301/302 policy, redirect chains, and collision tests.
Build a Server-Sent Events Broadcast Service
A complete SSE service: event streams, per-channel fan-out, resumable Last-Event-ID, heartbeats, backpressure, and reconnect tests.
Build an Image Thumbnail Generation Service
A complete thumbnail service: upload validation, async sharp processing, multiple sizes, content-addressed storage, and malformed-input tests.
Build a URL Metadata Scraper Service
A complete URL metadata scraper: SSRF guards, robots-aware fetching, OpenGraph and Twitter card parsing, caching, and hostile-input tests.
Build an Outbound Webhook Delivery Service
A complete outbound webhook delivery service: signed payloads, per-endpoint retries with backoff, circuit breaking, and delivery log tests.
Build a Config-Driven API Mock Server
A mock server that reads route definitions from a JSON file with wildcard matching, latency injection, conditional responses, and a recording mode that replays real upstream traffic as fixtures.
Build a Tagged Bookmark Manager CLI
A command-line bookmark manager that saves URLs with tags, searches across title, URL, and tags, opens the best match, and persists everything to a JSON file.
Build a Changelog Generator from Commit Messages
A CLI that reads conventional commit messages, groups them into features, fixes, and chores, and writes a Markdown changelog section for a version, from a git log or a file.
Build a Chart Generation CLI with SVG Output
A command-line tool that turns CSV data into publication-quality SVG charts: bar, line, and sparkline outputs with sensible defaults, theme colors, and deterministic rendering.
Build a Searchable Command History CLI
A tool that parses your shell history file, indexes commands by frequency and recency, and ranks fuzzy matches so the command you want is the first result.
Build a Config Center with Layered Overrides
A configuration service that merges file, environment, and database layers with explicit precedence, exposes merged values over HTTP, and validates every layer against a schema.
Build a Cron Job Dashboard with Schedules and Run History
A web dashboard that manages cron schedules in a database, executes jobs with isolated workers, captures run history and logs, and alerts on failures and missed runs.
Build a Cron Expression Parser and Job Runner
A scheduler that parses standard five-field cron expressions, computes the next run time, executes registered jobs on schedule, and prints upcoming runs for any expression.
Build a CSV to HTML Report Generator
A CLI that reads a CSV file, groups rows by a chosen column, and writes a self-contained HTML report with summary tables, totals, and escaped cell values.
Build a CSV to SQL Converter with Type Inference
A CLI that reads CSV files, infers column types, generates CREATE TABLE and batched INSERT statements, and streams the conversion so million-row files convert with flat memory.
Build a Cursor-Pagination REST API
A read-only REST API that serves a large synthetic dataset using opaque cursor pagination, stable ordering, and page-size limits, with tests that prove no record is skipped or repeated across pages.
Build a One-Way Directory Sync Tool
A command-line tool that mirrors a source directory into a target by copying new and changed files, deleting extras in the target, and reporting every action, with a dry-run mode.
Build a Perceptual Duplicate Image Finder
A CLI that scans an image folder, computes a perceptual hash for each file, groups near-duplicates by Hamming distance, and reports clusters without deleting anything.
Build a Text Template Rendering Library
A small template engine that renders placeholders, conditionals, and loops into text, escapes HTML on demand, and ships both a library API and a CLI.
Build an Environment Variable Manager CLI
A CLI that parses .env files with full quoting rules, merges them with process environment, validates against a schema, and detects leaked secrets before they reach git.
Build a CSV to SQLite ETL Pipeline
An extract-transform-load pipeline that reads CSV files, validates and typecasts rows against a schema, loads them into SQLite in batches, and reports rows accepted and rejected.
Build a Persistent Expense Tracker CLI with Reports
A command-line expense tracker that records dated expenses with categories, persists them to a CSV file, and prints monthly and per-category summaries with totals.
Build a Content-Addressed File Deduplicator
A CLI that finds duplicate files by size, then partial hash, then full SHA-256, reports reclaimable space, and optionally replaces duplicates with hard links or a content-addressed store.
Build a Text File Search Index and Query CLI
A tool that walks a directory, builds an inverted index of words to documents, persists the index to disk, and answers ranked keyword queries from the command line.
Build a Git Commit Statistics CLI
A CLI that parses git log output, reports commit counts per author and per day, tracks insertions and deletions, and highlights the busiest files, all from a local repository.
Build an HTTP Server with Graceful Shutdown
An HTTP service that drains in-flight requests on shutdown, stops accepting new connections, runs cleanup hooks, and exits within a bounded timeout, documented with tests.
Build a Batch Image Resizer CLI
A command-line tool that walks a folder of images, resizes each to a target width while preserving aspect ratio, skips files already small enough, and reports before and after sizes.
Build an Incremental Backup Tool with Snapshot Catalogs
A backup CLI that takes content-defined chunked snapshots, stores new chunks only, and restores any snapshot exactly, with verification and pruning of unreferenced chunks.
Build an In-Process Job Queue with Workers and Retries
A durable background job queue that persists tasks to disk, runs them through a bounded worker pool, retries failures with backoff, and exposes a CLI to enqueue jobs and inspect the queue.
Build a JSON Schema Validator from Scratch
A dependency-free JSON Schema draft-07 subset validator covering types, formats, combinators, and complex keywords like oneOf, $ref, and patternProperties with precise error paths.
Build a JSON-RPC 2.0 Server
A JSON-RPC 2.0 server over HTTP that dispatches methods, supports batch requests, returns spec-compliant errors, and validates parameters per method.
Build a Minimal JWT Authentication Service
A small authentication service that issues HMAC-signed JSON Web Tokens, verifies them on protected routes, enforces expiry, and rejects tampered tokens with clear errors.
Build a Log Aggregator with Structured Storage
A log pipeline that ingests newline-delimited JSON from multiple writers, stores events in SQLite with generated columns, and answers filtered tail queries over a CLI and HTTP API.
Build a Markdown Static Site Generator
A from-scratch static site generator that reads a folder of Markdown files, renders a shared layout, resolves internal links, and emits a browsable dist directory you can host anywhere.
Build a Mini Package Manager with Semver Resolution
A toy package manager that resolves semver ranges into a deterministic lockfile, fetches tarballs from a local registry, and installs verified packages into node_modules.
Build an Encrypted Password Vault CLI
A command-line vault that encrypts stored credentials with a passphrase-derived key using scrypt and AES-GCM, stores them in one file, and lists or reveals entries on demand.
Build a Rate Limiting Reverse Proxy in Node.js
A streaming reverse proxy that enforces token bucket and fixed window limits per API key before proxying, with standard 429 responses and Retry-After headers.
Build an RSS Feed Aggregation CLI
A feed reader that fetches multiple RSS and Atom feeds, normalises their items into one schema, de-duplicates by link, sorts by date, and renders a readable digest or JSON output.
Build a Contact Book REST API with SQLite
A small REST API for contacts backed by SQLite, with validated creation, case-insensitive search, pagination, and a migration step that creates the schema on first boot.
Build a Short Link Service with Node.js and SQLite
A dependency-light URL shortener using better-sqlite3 with WAL mode, code collision retries, click analytics, and integration tests, all in one process.
Build a TCP Key-Value Store Server and Client
A line-oriented TCP server that stores keys in memory with optional persistence, supports GET, SET, DEL, and KEYS commands, and ships a client that speaks the same protocol.
Build a Persistent Todo CLI with Node.js and JSON Storage
A complete command-line todo manager with add, list, done, and remove commands, disk persistence, filtering, and unit tests for every command path.
Build a Self-Hosted Uptime Monitor Service
A small service that periodically checks configured endpoints, records up and down transitions with timestamps, exposes a status endpoint, and prints a running summary.
Build a Concurrent URL Health Checker CLI
A command-line tool that checks a list of URLs concurrently, follows redirects, records status and response time, retries transient failures, and prints a pass-fail summary.
Build a Webhook Forwarder with Signed Retries
A webhook relay that queues inbound events, delivers them downstream with HMAC signatures, retries with exponential backoff, and exposes delivery status per event.
Build a Real-Time Polling Dashboard with Hono and Server-Sent Events
A complete real-time polling app with Hono and Server-Sent Events, including vote deduplication, SSE reconnection, tests, and scaling limits.
Build a URL Shortener REST API with Express and Prisma
A complete URL shortener API with Express, Prisma, PostgreSQL, and Redis, including validation, analytics, rate limiting, tests, and deployment.
Build a Real-Time WebSocket Chat Server
A complete Node.js WebSocket chat server with rooms, message history, rate limiting, heartbeat, reconnection, tests, and honest scaling limits.