backend-architect

backend-architect is a skill for Claude Code from tranhieutt/software_development_department. It costs 44 tokens per session (1,075 once invoked), scanned A, original, MIT.

A workflow for designing backend architecture, meaning the structure of server-side systems and how their services, APIs, databases, and communication fit together. It covers service boundaries, resilience, security, caching, and monitoring.

In plain words
What is it for?
Use it to design APIs, split systems into services, choose between synchronous requests and asynchronous messages, plan data stores, and document trade-offs.
Why use it?
It helps turn requirements such as scale, speed, and reliability into clear technical decisions before implementation begins.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to design APIs, split systems into services, choose between synchronous requests and asynchronous messages, plan data stores, and document trade-offs.

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Install with agentmods
npx agentmods add skills/tranhieutt/software_development_department/backend-architect
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 tranhieutt/software_development_department --skill backend-architect
Clone the repo
git clone --depth 1 https://github.com/tranhieutt/software_development_department

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
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Your own site
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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.

agentmods 80×15 button for backend-architect

Your own site · 80×15
<a href="https://agentmods.dev/skills/tranhieutt/software_development_department/backend-architect"><img src="https://agentmods.dev/badge/skills/tranhieutt/software_development_department/backend-architect.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,075 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 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 $0.00044 $0.01075
Opus 5 $0.00022 $0.00537
Sonnet 5 $0.00009 $0.00215
Haiku 4.5 $0.00004 $0.00108

Measured 9d ago against content hash 1a36c9efe737, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, 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 9d 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/skills/backend-architect/SKILL.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Architect

Workflow

  1. Capture requirements: Domain context, use cases, NFRs (scale, latency, consistency)
  2. Define service boundaries: DDD bounded contexts, service decomposition
  3. Design API contracts: REST/GraphQL/gRPC with versioning strategy
  4. Plan communication: Sync (REST, gRPC) vs async (queues, events)
  5. Build in resilience: Circuit breakers, retries, timeouts, graceful degradation
  6. Design observability: structured logging, RED metrics, distributed tracing
  7. Security: Auth/Z strategy, rate limiting, secrets management
  8. Caching: Layer strategy (app → API → CDN) with invalidation plan
  9. Document: Service diagram (Mermaid), ADRs, trade-offs

API design decision matrix

Use case Protocol Reason
Standard CRUD API REST Widest tooling support
Client queries complex data GraphQL Reduces over-fetching
Internal service-to-service gRPC Typed contracts, low latency
Real-time bidirectional WebSocket Full duplex
Server push (one-way) SSE Simpler than WS for unidirectional
High-volume async work SQS/Kafka Decoupling, retry, backpressure

Service boundary rules (non-obvious)

  • Bounded context = 1 database — shared DB across services creates hidden coupling; eventual consistency is the price of independence
  • Sync calls create latency chains — A → B → C means P99(A) = P99(A) + P99(B) + P99(C); use async for non-blocking flows
  • Saga over 2PC — distributed transactions via saga (choreography or orchestration); 2PC blocks and creates distributed deadlocks
  • Stateless for horizontal scale — session state in Redis/DynamoDB, not in memory
  • Database per service, not schema per service — separate schemas in shared DB = shared schema migrations = coupling still exists

Resilience patterns (always include these)

Circuit Breaker: CLOSED → [failures > threshold] → OPEN → [timeout] → HALF-OPEN → [success] → CLOSED
Retry: exponential backoff with jitter — base_delay * 2^attempt + random(0, base_delay)
Timeout: always set; propagate deadline via context/headers
Bulkhead: separate thread pools per dependency; one slow dep shouldn't starve others
Idempotency: every mutating operation needs idempotency key; store result, return on duplicate

Read the full file on GitHub · 97 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. 9d ago First seen · 97 lines · 44 tokens per session scan A 1a36c9efe737

Subscribe to this mod's changes

backend-architect is a skill published in the GitHub repository tranhieutt/software_development_department (72 stars, last pushed 3mo ago), licensed MIT. It adds 44 tokens to every session and 1,075 once invoked, about $0.0002 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.