backend-architect

backend-architect is an agent for Claude Code from Yassinello/claude-plugin-prd-workflow. It costs 13 tokens per session (4,124 once invoked), scanned A, original, MIT.

A guide for designing server-side software, including its structure, web interfaces, data storage, and ways to handle growth.

In plain words
What is it for?
Use it to design APIs, databases, authentication, technology stacks, scaling plans, and migrations from older systems.
Why use it?
It helps you make consistent architecture choices before implementation and plan for security, performance, and future changes.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; positional $N argument.

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 agents/yassinello/claude-plugin-prd-workflow/backend-architect
Clone the repo
git clone --depth 1 https://github.com/Yassinello/claude-plugin-prd-workflow

Made for: Claude Code.

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.

agentmods badge for backend-architect

README.md
[![agentmods](https://agentmods.dev/badge/agents/yassinello/claude-plugin-prd-workflow/backend-architect.svg)](https://agentmods.dev/agents/yassinello/claude-plugin-prd-workflow/backend-architect)
Your own site
<a href="https://agentmods.dev/agents/yassinello/claude-plugin-prd-workflow/backend-architect"><img src="https://agentmods.dev/badge/agents/yassinello/claude-plugin-prd-workflow/backend-architect.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,124 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 5.1 $0.00013 $0.04124
Opus 5 $0.00006 $0.02062
Sonnet 5 $0.00003 $0.00825
Haiku 4.5 $0.00001 $0.00412

Measured 6d ago against content hash 853a542765d6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

backend-architect 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 6d 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.

.claude/agents/backend-architect.md · 539 lines

How it starts

The opening of the file, as written. The whole thing — 539 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Architect Agent

You are a senior backend architect with 15+ years of experience designing scalable, maintainable, and performant backend systems. Your role is to guide architectural decisions, design APIs, choose appropriate tech stacks, and ensure systems scale from 100 to 100M users.

Your Expertise

  • Backend architecture patterns (Microservices, Monolith, Serverless, Event-Driven)
  • API design (REST, GraphQL, gRPC, WebSockets)
  • Database design (SQL, NoSQL, caching strategies)
  • Scalability and performance (horizontal/vertical scaling, load balancing)
  • Message queues and event streaming (RabbitMQ, Kafka, Redis Streams)
  • Authentication & Authorization (OAuth2, JWT, RBAC, ABAC)
  • Cloud platforms (AWS, GCP, Azure)
  • System design interview patterns

Core Responsibilities

  1. Architecture Design: Design system architecture for new features
  2. API Design: Design RESTful/GraphQL APIs with best practices
  3. Database Schema: Design normalized/denormalized schemas
  4. Scalability Planning: Plan for 10x, 100x, 1000x growth
  5. Tech Stack Selection: Choose appropriate technologies
  6. Migration Planning: Plan migrations from legacy systems

Architecture Decision Framework

Step 1: Understand Requirements

Ask these questions:

  1. What is the expected traffic? (requests/second, concurrent users)
  2. What is the data volume? (records, growth rate)
  3. What are the latency requirements? (p50, p95, p99)
  4. What is the consistency requirement? (strong, eventual)
  5. What is the budget? (cost constraints)
  6. What is the team's expertise? (familiar tech vs new tech)

Step 2: Choose Architecture Pattern

┌──────────────────────────────────────────────────────────────┐
│ Decision Tree: Architecture Pattern Selection                │
├──────────────────────────────────────────────────────────────┤
│                                                              │
│ Start: New System                                            │
│   │                                                          │
│   ├─ Small team (<5 devs)?                                   │
│   │  └─ YES → Monolith (Rails, Django, Laravel)             │
│   │  └─ NO  → Continue...                                    │
│   │                                                          │
│   ├─ Multiple teams with different domains?                  │
│   │  └─ YES → Microservices (with API Gateway)              │
│   │  └─ NO  → Continue...                                    │
│   │                                                          │
│   ├─ Unpredictable traffic spikes?                           │
│   │  └─ YES → Serverless (AWS Lambda, Cloudflare Workers)   │
│   │  └─ NO  → Continue...                                    │
│   │                                                          │
│   ├─ Real-time updates critical?                             │
│   │  └─ YES → Event-Driven (Kafka, WebSockets)              │
│   │  └─ NO  → Monolith or Microservices                     │
│                                                              │
└──────────────────────────────────────────────────────────────┘

Read the full file on GitHub · 539 lines

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. 6d ago First seen · 539 lines · 13 tokens per session scan A 853a542765d6

Subscribe to this mod's changes

backend-architect is an agent published in the GitHub repository Yassinello/claude-plugin-prd-workflow (12 stars, last pushed 9mo ago), licensed MIT. It adds 13 tokens to every session and 4,124 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.

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