Microservices and events
- Event-driven architecture with messaging
- Decoupled domains that scale on their own
- Review of an existing architecture
- Legacy migration plan
Systems that cannot stop.
Shiftvibex designs and builds critical software for payments, credit, digital government and healthcare, with Spec-Driven Development and AI agents: faster deliveries that scale and stay traceable.
What we deliver
Payments and integrations
- Payment gateways and reconciliation
- Integration with government systems
- VTEX, TOTVS and third-party APIs
- Marketplace, cart and headless checkout
- Rule engines in Node-RED
Cloud, DevOps and observability
- AWS and GCP: Cloud Run, Functions, Firestore
- Terraform, Docker and Kubernetes
- CI/CD with GitHub Actions, Jenkins and Cloud Build
- Metrics, logs and traces in Datadog
SDD and technical leadership
- Spec-Driven Development with AI agents
- PRD, technical plan and QA before the code
- Technical leadership of product teams
- Code standards, Clean Code and code review
- On-call and incident response
Work
Systems in production. Some were delivered by Shiftvibex; others by Luan Reis as engineer and tech lead.
I lead MevoFarma’s new transactional platform: storefront, cart, checkout and orders moving from a SaaS to an in-house architecture, as one marketplace for the own store and partner pharmacies. Alongside it, I build the products already running in production.
- Spec-driven specification: decisions recorded as ADRs, C4 at all three levels and orders modelled as a state machine
- Checkout decoupled from the platform, with a typed BFF and the cart in an httpOnly cookie (LGPD)
- Catalogue projected to Google Merchant Center with an outbox pattern and atomic claims
- Multi-brand CMS with page editor, workspaces and access control
- Authentication and SSO SDK adopted by the company’s frontends and backends
- Catalogue health dashboard and a serverless sitemap including drug-leaflet pages
In onCar’s Financial Services squad, the technology and credit arm of Grupo Tony Veículos, I lead the engineering of the new onCar Crédito site: a domain move without losing leads or SEO, and an A/B test that measures leads per visitor.
- Project TDD: domain migration with host routing, 301 redirects, canonical and sitemap per domain
- Server-side A/B test with GrowthBook and sticky bucketing, with the variant carried on the lead into the CRM
- Next.js BFF that keeps API credentials on the server only, with timeouts and handled errors
- Personal data masked in Clarity (LGPD) and funnel events in the dataLayer through to WhatsApp
- Partner dealer onboarding with schema validation and a dedicated Lambda
São Paulo’s new simplified vehicle licensing. Architecture, backend and integrations with government systems, sized for 30 to 50 thousand records a day.
The first version of a payment gateway integrated with GoMoney: the code foundation, later handed to an international team.
Rent guarantee and life insurance: legacy modernisation, Node.js APIs on Docker, Kubernetes and Terraform, and Node-RED rule engines.
A telemedicine platform and electronic health record systems for clinics, with patient data retention routines.
A move to NestJS, Cloud Run and Firestore with Terraform: 60% faster responses and more scale without changing databases.
RPA bots, sales management and transport apps for healthcare, mobility, e-commerce and enterprise clients.
In numbers
50k - records a day in the capacity designed for Detran Pay.
60% - faster responses on the APIs moved to Cloud Run.
70% - fewer manual deployment steps with CI/CD pipelines.
12 - developers led today at Mevo.
8 yrs - in financial services, from Itaú Unibanco to Porto Bank.
Spec-Driven Development
The specification is the source of truth, and AI agents work in every phase under human review. The team ships faster, scales without losing direction, and every decision stays traceable from spec to deploy.
Specification
- Discovery with business and operations
- agent + Luan
- PRD with acceptance criteria
- PRD
Technical plan
- Architecture decisions
- ADR
- Context, containers and components
- C4
- Plan review by a reviewer agent
- gate
Build and QA
- Epics and stories generated and audited
- backlog
- Implementation driven by the spec
- code
- Tests from the acceptance criteria
- QA
Software traceable from spec to deploySDD
Principles
The rules we follow when designing systems that handle money and health.
The spec comes before the code.
PRD, technical plan and acceptance criteria define what gets built. AI agents speed up every phase; the final call is always reviewed by a person.
Three backends, not one.
Storefront, checkout and orders differ in load, caching and cost of failure. A campaign spike must never take down payment for people already buying.
Price never comes from the browser.
The cart holds a signed offer, never the amount. The server re-quotes before charging and recalculates the total at checkout.
PCI scope in a single service.
Only checkout talks to the payment gateway. When an order needs a refund, it asks checkout.
One owner for each state.
Neighbours announce that something changed. One service decides the order state, with validated transitions.
Configuration over special code.
Business rules ship switched off and are turned on by parameter, without a deploy and without hidden code paths.
Node.jsNestJSTypeScriptNext.jsReactPrismaAngular
AWSECS FargateLambdaSQSSNSGoogle CloudKubernetesTerraformPostgreSQLRedis
DatadogGitHub ActionsGrowthBookPlaywrightVitestJestVTEX IOC4 ModelADR
Luan ReisFounder of Shiftvibex · São PauloLinkedIn
Who is behind it
I started in banking, at Itaú Unibanco. That is where I learned what a system that cannot stop means: every minute of downtime is a customer locked out of their own money.
Then came four years of engineering at Porto Bank, on rent guarantee and life insurance, with production on-call and a lot of legacy modernisation.
Shiftvibex started in 2023 to bring that care to other teams. That is how I came to architect Detran Pay and write the first version of a payment gateway.
Today I am e-commerce Tech Lead at Mevo, a digital health platform, leading engineering on MevoShop 2.0, and work in the engineering of onCar’s Financial Services squad, on vehicle-backed credit. I hold an MBA in Software Architecture from FIAP, work in Node.js, NestJS, TypeScript and Next.js, and run development through Spec-Driven Development with AI agents: I write the decisions down before the code.
If your system needs to grow without falling over, tell me the context. I reply in person.
Start with the context
Every project starts with an ADR. Describe the problem and watch the draft take shape beside it: it lands straight in my inbox, and I reply within 2 working days.