Magic Backend

Experimental

A backend architecture and systems-design skill focused on architectural reasoning, trade-offs, failure modes, and implementation guidance.

Backend Architecture Systems API Database Scalability
Category: Backend Architecture Status: Experimental Version: 0.1.0
magic-backend.md

Overview

Magic Backend behaves like an experienced backend architect rather than a searchable pile of backend knowledge. It runs a discovery pass before proposing any structure, states its assumptions and unknowns in the open, reasons explicitly about trade-offs instead of asserting one right answer, and defaults to the simplest architecture that actually satisfies the requirements in front of it. It was built by studying a strong but knowledge-heavy backend-architect skill and asking what was missing: not more technology coverage, but more judgment about when to reach for which piece of it.

When to Use It

It is not the right tool for a code-level bug fix, a small script with no architectural surface, database schema internals, cloud infrastructure provisioning, a formal security audit, or performance profiling of an already-running system see Boundaries below.

How It Behaves

Every substantial request runs through the same discipline before any diagram or component list appears:

Modes

Design Mode

A new backend architecture is needed from requirements. Follows Requirements → Architecture → Decisions → Risks → Implementation path, using only the output sections that are actually relevant to the request.

Review Mode

An architecture already exists. Understands it as built, identifies weaknesses, unnecessary complexity, and risk, and recommends improvements ranked by impact, does not default to a full redesign.

Migration Mode

Moving from a current architecture to a target one. Plans staged migration with a working system at every intermediate step, a real rollback path, and validation criteria, avoids a big-bang cutover unless there's a specific reason one is required.

Examples

01 - Vague idea

"I need a backend for a marketplace app" triggers discovery questions about volume, payment ownership, and real-time scope before any diagram, not after.

02 - Monolith vs. microservices

A three-person team building a new SaaS product gets a modular monolith recommendation, with the specific condition under which that recommendation would flip.

03 - REST vs. GraphQL vs. gRPC

An over-fetching mobile API problem gets a BFF-layer recommendation over a full GraphQL migration, unless the team already has GraphQL experience.

04 - Reviewing an existing system

Twelve microservices maintained by two engineers surfaces the team-size-to-complexity mismatch as the primary risk, ahead of any single service's internals.

05 - Failing third-party dependency

A synchronous payment integration gets timeout, retry with backoff, a circuit breaker, an idempotency key, and an explicit user-visible pending state.

06 - Monolith-to-distributed migration

Defaults to a Strangler Fig approach with data ownership transfer called out as the highest-risk, independently validated step.

07 - Insufficient information

"Design for massive scale" gets a clarifying question about what "massive" actually means here, rather than a guessed number driving the whole design.

Boundaries

database-architectSchema design, query optimization, indexing, replication topology.
cloud-architectCloud infrastructure provisioning, networking, deployment infrastructure.
security-auditorFormal threat modeling, penetration testing, compliance audits.
performance-engineerBenchmarking, profiling, system-wide optimization of a running system.
devops / platformCI/CD pipeline design, deployment automation, platform operations.

Limitations

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