What is backend-development?

A guide to building server-side software, including APIs, databases, authentication, testing, security, and deployment. Server-side software handles data and business rules behind an application.

Use it to design REST, GraphQL, or gRPC APIs, build login systems, optimize databases, add caching, test services, or plan deployments.

It helps choose suitable technologies and avoid common problems with data access, security, reliability, and growth.

backend-development — Skill for Claude Code and Codex by duongductrong

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add duongductrong/cursor-kit --skill backend-development

Clone the repo

git clone --depth 1 https://github.com/duongductrong/cursor-kit

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/duongductrong/cursor-kit/backend-development/github.svg)](https://agentmods.dev/skills/duongductrong/cursor-kit/backend-development)

Your own site

<a href="https://agentmods.dev/skills/duongductrong/cursor-kit/backend-development"><img src="https://agentmods.dev/badge/skills/duongductrong/cursor-kit/backend-development/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/duongductrong/cursor-kit/backend-development"><img src="https://agentmods.dev/badge/skills/duongductrong/cursor-kit/backend-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 135 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,039 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin 86% copy Near-identical to another mod in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00135	$0.01039
Opus 5.5	$0.00054	$0.00416
Sonnet 5.5	$0.00027	$0.00208
Haiku 4.5	$0.00014	$0.00104

Measured 1mo ago against content hash 68e7dbc0221c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

backend-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

86% identical to ck:backend-development — 5 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

templates/skills/backend-development/SKILL.md · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Development Skill

Production-ready backend development with modern technologies, best practices, and proven patterns.

When to Use

Designing RESTful, GraphQL, or gRPC APIs
Building authentication/authorization systems
Optimizing database queries and schemas
Implementing caching and performance optimization
OWASP Top 10 security mitigation
Designing scalable microservices
Testing strategies (unit, integration, E2E)
CI/CD pipelines and deployment
Monitoring and debugging production systems

Technology Selection Guide

Languages: Node.js/TypeScript (full-stack), Python (data/ML), Go (concurrency), Rust (performance) Frameworks: NestJS, FastAPI, Django, Express, Gin Databases: PostgreSQL (ACID), MongoDB (flexible schema), Redis (caching) APIs: REST (simple), GraphQL (flexible), gRPC (performance)

See: references/backend-technologies.md for detailed comparisons

Core Technologies:

backend-technologies.md - Languages, frameworks, databases, message queues, ORMs
backend-api-design.md - REST, GraphQL, gRPC patterns and best practices

Security & Authentication:

backend-security.md - OWASP Top 10 2025, security best practices, input validation
backend-authentication.md - OAuth 2.1, JWT, RBAC, MFA, session management

Performance & Architecture:

backend-performance.md - Caching, query optimization, load balancing, scaling
backend-architecture.md - Microservices, event-driven, CQRS, saga patterns

Quality & Operations:

backend-testing.md - Testing strategies, frameworks, tools, CI/CD testing
backend-code-quality.md - SOLID principles, design patterns, clean code
backend-devops.md - Docker, Kubernetes, deployment strategies, monitoring
backend-debugging.md - Debugging strategies, profiling, logging, production debugging
backend-mindset.md - Problem-solving, architectural thinking, collaboration

Key Best Practices (2025)

Security: Argon2id passwords, parameterized queries (98% SQL injection reduction), OAuth 2.1 + PKCE, rate limiting, security headers

Read the full file on GitHub · 96 lines

Files

What ships with it

11 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago First seen · 96 lines · 135 tokens per session scan A 68e7dbc0221c

Subscribe to this mod's changes

backend-development is a skill published in the GitHub repository duongductrong/cursor-kit (23 stars, last pushed 7mo ago), licensed MIT. It adds 135 tokens to every session and 1,039 once invoked, about $0.0005 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to ck:backend-development, differing in 5 lines, and is treated as a copy.

Backend and APIs Databases cursor cursor-kit github-copilot

iblai-api-profile-metadata

Read and write per-user, per-organization metadata via the platform API — a key-value store for user preferences, app settings, feature flags, and onboarding progress. Defaults to the signed-in user; admins can target another user. Use to persist per-user state.

iblai/api · 60 tokens

cqrs-implementation

Implement Command Query Responsibility Segregation for scalable architectures. Use when separating read and write models, optimizing query performance, or building event-sourced systems.

wshobson/agents · 35 tokens

event-store-design

Design and implement event stores for event-sourced systems. Use when building event sourcing infrastructure, choosing event store technologies, or implementing event persistence patterns.

wshobson/agents · 33 tokens

supabase-cli

This skill should be used when user asks to "use supabase CLI", "supabase init", "supabase start", "run migrations", "deploy edge functions", "manage Supabase project", or works with the supabase command-line tool for local development and project management.

fcakyon/claude-codex-settings · 60 tokens

supabase-js

This skill should be used when user asks to "use supabase-js", "query Supabase database", "supabase auth", "supabase storage", "supabase realtime", "supabase edge functions", or works with the @supabase/supabase-js JavaScript/TypeScript SDK.

fcakyon/claude-codex-settings · 64 tokens

durable-objects

Build, debug, or review Cloudflare Durable Objects code for persistent state and coordination.

fcakyon/claude-codex-settings · 22 tokens

backend-development