Diffy Studio / Engineering Case Studies
PHP, MariaDB, integrations, and workflow engineering shaped around real business operations—where state, failure, and handoff matter.
Engineering posture
The strongest systems here start with operational truth: what makes a transaction unique, which event may advance it, what can safely repeat, and where a person needs to decide.
WordPress is often the application host, but the engineering work is custom backend behavior: data models, signed boundaries, lifecycle rules, REST interfaces, atomic writes, third-party coordination, and operational recovery.
Technical descriptions are derived from inspected implementation evidence. First-person ownership and operating context are Jake's account. Diagrams are reconstructed, and no raw client data, source, workflow exports, production logs, or private endpoints are published.
Selected systems / 05
Five implementation stories with the architecture, ownership, safeguards, tradeoffs, and boundaries left visible.
A transaction-centered rental operations system
A custom PHP and MariaDB application layer coordinating website leads, rental records, CRM objects, inventory, documents, reporting, and customer communication.
Read case studyPay-first intake and evaluator fulfillment
A WordPress workflow joining payment, signed intake, state routing, human review, document generation, and customer delivery without duplicate fulfillment.
Read case studySingle-use invitation security
A focused invitation mechanism using expiring random tokens, HMAC storage, constant-time validation, secure cookies, and atomic consumption.
Read case studyReversible WooCommerce data normalization
A deterministic Python and WP-CLI migration that normalized product variations while preserving IDs, prices, and stock and keeping every change reviewable.
Read case studyRental discovery through quote operations
A PHP and JavaScript rental catalog that carries customer selections into a persistent quote workflow and an operator-facing status pipeline.
Read case studyCross-project index
Custom application logic, REST endpoints, workflow boundaries, WordPress as an application framework.
Application-level schemas, unique keys, reporting indexes, prepared queries, and atomic conditional updates.
CRM, payments, documents, email, inventory, and workflow orchestration with normalized boundaries.
Idempotency, replay safety, stale-event protection, dry runs, snapshots, rollback, and failure handling.
HMAC signatures, token hashing, constant-time checks, secure cookies, nonces, sanitization, and throttling.
Linux VPS, NGINX, RunCloud, WP-CLI, SSH, DNS, SSL, backups, migrations, and deployment scripts.
About
I am a production-tested PHP/backend developer focused on systems that connect software behavior to real business operations.
Agency and client work taught me to translate business requirements, build the implementation, deploy it, and stay responsible when the system meets real operations. My work centers on durable data models, dependable integrations, explicit workflow boundaries, and practical recovery when systems do not behave as planned.
Email Jake