Projects

Architecture decisions in real systems.

The problem, what I decided and what changed. Internal details of companies and clients have been omitted for confidentiality.

E7Lab Marketplace Seller Center TutorVest Vehicle itinerary compliance
E7Lab · Client project

How E7Lab transformed the engineering of a client’s project

The project came to E7Lab with no engineering processes, no code review and no coding standards, running on a single environment and missing deadlines. We took over the technical side and restructured the team’s management, architecture and culture.

Context
Project for an E7Lab client
My role
Solutions Architect and partner: technical lead of the transformation
Period
06/2026 — present
1 → 3 environments, with component parity
15 days sprints with planning, retrospective and capacity
CI/CD automated deploys, with rules per environment and per person

Before and after

Before With E7Lab
Management
Alignment only 2–3 times a week, run by the client’s project manager from a spreadsheet
15-day sprints in Jira, with planning, retrospective, capacity and an owner for each stage
Predictability
Missed deadlines
Work organized into epics, technically refined and estimated before each sprint
Code quality
No code review and no standards: mixed Portuguese and English, security flaws, inconsistent rules and low fidelity to the prototype
Defined code review, pre-commit and pre-push hooks, MR validation and protected branches
Environments & deploy
A single environment, with deploys pushed onto the cloud infrastructure support team
Three environments with component parity and automated pipeline deploys
Architecture
Unused and unnecessary applications, with no endpoint catalog
Services reduced to what is needed, a boilerplate with CQRS, DDD and Clean Architecture, Swagger and ADRs
Data
Unnormalized SQL database with heavy JSONB usage and application bottlenecks
Defined SQL database standards and Grafana dashboards for infrastructure and application
Team & communication
Little communication within the team and no Teams channels
Dailies, one-on-ones, weekly follow-ups and Teams channels for MRs, change management and wins

The new flows

Work item flow in Jira
  1. Sprint backlog
  2. In progress
  3. Review
  4. Ready for staging
  5. …
From commit to deploy
  1. pre-commit
  2. pre-push
  3. Validated MR
  4. Code review
  5. Automated deploy

What we put in place

Project management
Jira board Stories, bugs, improvements, tasks and incidents 15-day sprints Sprint Planning Sprint Retrospective Capacity Card templates Epics Technical refinement Estimates Owners per stage
Architecture & engineering
3 environments Fewer services Private NPM boilerplate CQRS DDD Clean Architecture Code review CI/CD SQL standards ADRs Restructured front end Back/front contract Swagger NPM design system Grafana Protected branches pre-commit & pre-push Deploy per environment & person
Culture
One-on-ones Dailies Sprint Planning Sprint Retrospective Leadership follow-up MR channel Change management channel Wins channel
FCx Labs · Ferreira Costa

Marketplace Seller Center

The platform where sellers on Ferreira Costa's marketplace register, import and manage their products, integrated with the e-commerce platform and external integrators.

Context
Home-improvement retail marketplace
My role
Tech Lead of the Seller Center Products module, leading 4 developers
Period
10/2024 — 06/2026

The challenge

Keeping sellers' product data in sync across the Seller Center, the e-commerce platform and integrators such as AnyMarket and E-cross — with consistency, performance and a growing team.

Decisions & deliverables

  • Event-driven integrations with RabbitMQ, including dead letter queues and prefetch control
  • Migration from trigger-based materialized views to event-fed consolidated tables, recorded in an ADR
  • Separate read and write models with CQRS, plus Redis caching in the BFF
  • Boilerplate with modular architecture and DDD, and shared infrastructure in private NPM packages
  • PostgreSQL query optimization with execution plans and partial and composite indexes

Outcome

  • −47.5% in CI/CD pipeline time (80 → 42 min)
  • Team engineering standards: ADRs, Gitflow, Conventional Commits and semantic versioning
  • Event maps and synchronization flows documented for the team
TypeScript NestJS PostgreSQL RabbitMQ Redis gRPC Kubernetes (EKS) GitLab CI
Master's program · CESAR School

TutorVest

A personalized tutoring platform for Grupo GGE that moved student follow-up out of WhatsApp and spreadsheets into a single place, with impact metrics.

Context
Grupo GGE · Juntos Educação, a leading education group in Northeast Brazil
My role
Software Engineer: architecture, development and features, in a team of 5
Period
2026

The challenge

Each tutor spent half of their 12 weekly hours on planning alone, with schedules, plans and conversations scattered across Google Calendar, Docs and WhatsApp — and no metrics on the impact of tutoring.

Decisions & deliverables

  • NestJS back end modularized by domain and Next.js front end organized by access role
  • DDD, Clean Architecture, CQRS and TDD as development standards
  • Three access roles (admin, tutor and student) with JWT and RBAC
  • Gitflow with CI/CD on GitHub Actions and images published to Amazon ECR
  • AWS infrastructure with a VPC, public and private subnets, EC2 and S3

Outcome

  • MVP with 10 features validated and formally accepted by the client
  • Transactional emails delivered even though they were outside the initial scope
  • Requirement changes absorbed with low impact thanks to the modular architecture
Next.js NestJS TypeScript PostgreSQL TypeORM Docker AWS GitHub Actions
Read the full case study (in Portuguese)
Mobs2 · Telematics

Vehicle itinerary compliance

A system to track whether vehicles follow their scheduled itineraries, used to audit transportation operations.

Context
Vehicle telematics and public transportation
My role
Architecture design and backend development
Period
2024

The challenge

Comparing actual vehicle routes with scheduled itineraries and generating reliable reports without slowing down the main application.

Decisions & deliverables

  • Architecture design of the itinerary tracking service
  • Serverless architecture on AWS with API Gateway, SNS and SQS
  • Reports generated asynchronously and delivered by email

Outcome

  • The first project where I led the architecture design end to end
TypeScript NestJS PostgreSQL AWS Serverless SNS SQS S3

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