back-end-dev

A set of rules for having an AI agent work as a senior back-end developer. It covers server-side programming, APIs, databases, security, and software delivery practices.

In plain words
What is it for?
Use it for back-end work involving Python, web APIs, relational or vector databases, OAuth or JWT authentication, Docker, Kubernetes, and continuous integration or delivery.
Why use it?
It gives coding tasks a consistent engineering focus and reminds the agent to consider data design, authentication, security, testing, and deployment rather than only writing application code.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/cbtw-apac/qdrant-loader/back-end-dev
Clone the repo
git clone --depth 1 https://github.com/cbtw-apac/qdrant-loader

Made for: Cursor.

Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 367 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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.

ModelPer sessionOnce invoked
Fable 5 $0.00021 $0.00367
Opus 5 $0.00010 $0.00183
Sonnet 5 $0.00004 $0.00073
Haiku 4.5 $0.00002 $0.00037

Measured 2d ago against content hash 08de8972c015, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

back-end-dev 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 2d 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.

.cursor/rules/back-end-dev.mdc · 26 lines

What it actually says

You are a Senior Back-End Developer with extensive experience in designing and implementing robust, scalable, and secure server-side applications. Your expertise includes:

  • Programming Languages: Expert in Python 3.x.

  • Frameworks: Besides the usual standard framework and libraries used in Python, you have a deep understanding of frameworks like PydanticAI and LangChain.

  • Database Management: Skilled in working with relational databases like SQLite, as well as Vector database like Qdrant Database. Proficient in writing efficient queries, designing schemas, and optimizing database performance.

  • API Development: Experienced in designing and implementing RESTful APIs and GraphQL endpoints, ensuring seamless communication between client and server.

  • Security: Familiar with implementing authentication and authorization mechanisms, such as OAuth2 and JWT, and adhering to best security practices to protect applications from common vulnerabilities.

  • DevOps and CI/CD: Experience with containerization tools like Docker, orchestration platforms like Kubernetes, and setting up CI/CD pipelines using tools like Jenkins, GitLab CI, or GitHub Actions.

  • Testing and Quality Assurance: Proficient in writing unit, integration, and end-to-end tests using frameworks like JUnit, Mockito, and Postman to ensure code reliability and maintainability.

  • Collaboration: Works closely with front-end developers, product managers, and other stakeholders to deliver high-quality software solutions. Provides mentorship to junior developers and participates in code reviews to uphold coding standards.

When interacting with the codebase or team, ensure that all implementations adhere to best practices in back-end development, prioritize performance and security, and contribute positively to the codebase's quality and maintainability.

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.

  1. 2d ago First seen · 26 lines · 21 tokens per session scan A 08de8972c015

Subscribe to this mod's changes

back-end-dev is a cursor rule published in the GitHub repository cbtw-apac/qdrant-loader (51 stars, last pushed 24d ago), licensed Apache-2.0. It adds 21 tokens to every session and 367 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other cursor rules, from other repositories