senior-backend

Design contract-first backend APIs with migration and observability planning.

24|8|Updated Jan 14, 2026

Search Tags:#migrations #backend #observability #data-modeling #auth #api-design #design-docs

Ready to run

npx skills add https://github.com/vadimcomanescu/codex-skills --skill senior-backend-vadimcomanescu

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: senior-backend
Source: https://github.com/vadimcomanescu/codex-skills/tree/main/skills/.curated/platform/senior-backend
Command: npx skills add https://github.com/vadimcomanescu/codex-skills --skill senior-backend-vadimcomanescu

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) and assets (resource) components.

What problem does it solve?

Senior Backend provides structured workflows and checklists to avoid unsafe or unobservable backend changes, reducing incidents caused by unclear contracts, risky migrations, missing observability, and insufficient testing.

Core Features & Use Cases

Contract-first API Design: Define inputs, outputs, errors, and idempotency before implementation.
Data and Migration Planning: Ownership, schema changes, backfills, rollback strategies, and migration safety.
Operational Safety & Observability: Structured errors, logging, metrics, tracing, correlation IDs, and rollout/rollback guidance.
Use Case: Plan and review a breaking database migration and associated API changes with rollout flags, backfills, and monitoring hooks.

Quick Start

Use the senior-backend skill to draft a contract-first backend design doc that covers API contracts, data model changes, migration and backfill plans, observability, and rollout/rollback steps.

Frequently Asked Questions about senior-backend

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is contract-first API design and when do I need it for backend services?▼

Contract-first API design defines inputs, outputs, structured errors, and idempotency support before writing backend code. You need it to prevent unclear API contracts and ensure operational safety when building or updating reliable backend services.

How do I plan and execute safe database schema migrations with backfills?▼

Plan safe database migrations by defining schema ownership, backfill procedures, and rollback strategies before execution. This approach ensures migration safety and allows you to review breaking data model changes with rollout flags and monitoring hooks.

How do I design a backend design doc covering API contracts and observability?▼

Draft a backend design doc by structuring it around API contracts, data model changes, migration plans, observability, and rollout steps. This ensures your backend systems ship with structured errors, logging, metrics, and tracing correlation IDs.

What should I include in backend observability for reliable service operations?▼

Backend observability must include structured errors, logging, metrics, tracing, and correlation IDs. Integrating these elements into your services provides the operational safety needed to monitor rollouts and execute rollback plans effectively.

Can I use this approach for backend code reviews and breaking API changes?▼

Yes, this approach applies directly to backend code reviews for teams building services. It checks for authN/authZ support, idempotency, contract-first design, and migration safety to reduce incidents caused by risky or unobservable backend changes.

Why do backend changes cause incidents and how can I prevent them?▼

Backend changes cause incidents due to unclear contracts, risky migrations, missing observability, and insufficient testing. Prevent them by applying structured workflows that enforce migration safety, rollout flags, and comprehensive API contract design.