Gian
Barboza. Gian Barboza — Senior Backend Engineer specialized in payments infrastructure and AI automation

Thousands of dollars in monthly paid-ad spend, with a catalog of 1,600+ products per provider multiplied across multiple countries and services.

Reduce paid-ad dependency without hurting acquisition. Generating content at human scale for thousands of country/service/product combinations was unfeasible.

Hierarchical generation pipeline across 3 tiers (country → country/service → country/service/product), populating thousands of combinations via ChatGPT-4o with prompts curated per vertical. Automatic trigger: when a new product lands, affected landings are regenerated with zero manual intervention.

Payments platform exposed to two fraud vectors: transactional (stolen cards, suspicious patterns) and access-level (multi-accounts, account-takeover attempts).

Need to add new rules frequently without touching the central pipeline, and to detect suspicious account/device patterns without degrading the experience for legitimate users.

Rule engine based on Factory + Single Responsibility: each rule self-registers and receives normalized context, allowing extension without modifying the evaluator. Separate access-fraud layer using device fingerprinting. Explored contextual LLM evaluation via n8n to mimic support agents' decisions; it worked at small scale but was shelved due to prohibitive model costs.

Global gift cards and top-up operation where relying on a single gateway leaves gaps in geography, conversion, and availability.

Different gateways cover different countries and fees; any one of them can go down or start rejecting more. We needed continuous coverage and commercial flexibility to optimize per country and method.

Abstraction where the admin configures the active gateway and priorities per product. On failure or rejection from the active provider, automatic failover to the next in the chain. 5 processors integrated (PayPal, Payeezy, DLocal, Stripe, Shift4) with full features: 3DS, refunds, voids, Apple Pay, Google Pay, and in-house card tokenization.