Shopping cart and checkout flow design: cart architectures (session, DB, Redis, headless cart APIs), express checkout (Apple Pay, Google Pay, Shop Pay, Amazon Pay), shipping integration (ShipStation, Shippo, EasyPost), tax engines (Avalara, TaxJar), promotion/discount engine, cart recovery (Klaviyo, Omnisend), BOPIS (buy online pick up in-store), guest checkout, address validation, and checkout conversion optimization.
Make a paid API request to an x402 endpoint with automatic USDC payment. Use when you or the user want to call a paid API, make an x402 request, use a paid service, or pay for an API call. Use after finding a service with search-for-service.
Guides banking API integration: Open Banking standards (PSD2, UK Open Banking, FDX), Plaid integration (Link, transactions, balance, identity), account aggregation, payment initiation (PISP), account information (AISP), BaaS platforms (Unit, Synapse, Column), and API security (mTLS, OAuth2, FAPI). Use when integrating with banking services.
Telehealth system architecture covering HIPAA-compliant video consultation, remote patient monitoring, patient portal design, asynchronous telehealth, and billing integration with telehealth-specific CPT codes.
Payment gateway integration patterns for e-commerce: Stripe, PayPal, Adyen, Square, Mollie, Razorpay, Checkout.com, BNPL (Klarna, Affirm, Afterpay), crypto payments (BitPay, BTCPay), payment orchestration (Primer, Spreedly), 3DS2 authentication, fraud prevention (Sift, Riskified), subscription billing, refunds/disputes, multi-currency, and idempotency.
PCI DSS compliance for e-commerce: compliance levels (SAQ A, SAQ A-EP, SAQ D), cardholder data handling, tokenization (Stripe, Braintree tokens), secure payment forms (iframes, hosted fields), network segmentation, vulnerability scanning, penetration testing, and compliance audit preparation.
Guides transaction processing: ACID guarantees for financial operations, idempotency (idempotency keys, deduplication), distributed transactions (saga with compensating transactions), settlement workflows, batch processing, reconciliation, and transaction lifecycle state management. Use when implementing payment flows or financial operations.
Rewrite a feature branch's commit history into clean conventional commits that tell a progressive, linear story. Handles backup, soft reset, and atomic recommit. Use when: (1) Cleaning up messy WIP commits before PR, (2) Reorganizing commits into logical units, (3) Converting commits to conventional commit format. Triggers on: "rewrite history", "clean up commits", "rewrite commits", "conventional commits", "squash and rewrite", "reorganize commits".
Analyze and consolidate Flyway SQL migrations into clean, domain-grouped CREATE TABLE migrations for pre-production projects. Use when consolidating database migrations, refactoring Flyway schemas, simplifying migration history, grouping tables by domain, or when user mentions "consolidate migrations", "merge migrations", "clean up Flyway", "refactor schema", "baseline migrations".
High availability and replication topologies across all database engines. Synchronous/asynchronous/semi-synchronous replication, primary-secondary, multi-primary, quorum-based. PostgreSQL streaming/logical replication, MySQL GTID/Group Replication, MongoDB replica sets, Redis Sentinel/Cluster, Cassandra multi-DC. Consensus protocols (Raft, Paxos, Gossip). Failover automation, split-brain prevention. Use when designing HA architectures, configuring replication, or troubleshooting failover.
Use when investigating slow queries, analyzing execution plans, or optimizing database performance. Invoke for index design, query rewrites, configuration tuning, partitioning strategies, lock contention resolution.
This skill should be used when the user asks to "write a migration", "add a column", "add column to table", "create an index", "add a foreign key", "set up associations", "fix N+1 queries", "optimize queries", "add validations", "create callbacks", "use eager loading", or mentions ActiveRecord, belongs_to, has_many, has_one, :through associations, polymorphic associations, inverse_of, touch: true, counter_cache, dependent: destroy, where clauses, scopes, includes, preload, eager_load, joins, find_each, batch processing, counter caches, foreign key constraints, or database constraints. Should also be used when editing *_model.rb files, working in app/models/ directory, db/migrate/, discussing query performance, N+1 prevention, validation vs constraint decisions, or reviewing database schema design.
Discard local changes, switch to main, and pull latest
Configure Resend for transactional emails like password resets and email verification.
Design relational database schemas from requirements and generate migrations, TypeScript/Python types, seed data, RLS policies, and indexes. Handles multi-tenancy, soft deletes, audit trails, versioning, and polymorphic associations.
Database schema design principles and patterns. Normalization (1NF through 5NF/BCNF), strategic denormalization for read performance, multi-tenancy schema patterns (shared schema, schema-per-tenant, database-per-tenant), primary key strategies (UUID v7, ULID, KSUID, Snowflake ID, BIGSERIAL, CUID2, NanoID), soft delete patterns, temporal tables (SCD Type 1/2/3/4/6), audit trails, schema evolution (expand-contract pattern), naming conventions, data type best practices, and anti-patterns to avoid (EAV, polymorphic associations, god tables). Use when designing new schemas, reviewing existing schema design, planning schema migrations, or choosing PK strategies.
SQL database design, query optimization, and migration safety. Use when writing queries, designing schemas, or planning database migrations.
Drizzle ORM typesafe schema design, relational queries, prepared statements, migrations, and transactions. Use when working with Drizzle ORM, writing database queries, managing migrations, or optimizing query performance with prepared statements.
