Available for Engineering Roles & High-Impact Contracts

⚡ Full Stack & Systems

I build high-leverage full-stack applications & backend systems that scale, stay resilient, and automate manual workflows.

Full Stack Software Engineer with 5+ years in tech (3+ delivering production systems) across Python, TypeScript, JavaScript, and PHP. Specialized in end-to-end applications, microservices architectures, RESTful APIs, cloud-native GitOps (K3s/ArgoCD), and event-driven systems delivering 15–20% performance gains, Spec-Driven Development (SDD), Architecture Decision Records (ADR), and Model Context Protocol (MCP) multi-agent AI workflows.

Explore Featured Projects

gabriel_backend_core.py PROD • SDD & ADR

                  
                  from core.architecture import SpecDrivenService, ADR
                
                  from agentic.mcp import ModelContextProtocol, MultiAgentWorkflow
                
                  # 5+ yrs tech, 3+ yrs building & optimizing backend systems
                
                  class BackendEngine(SpecDrivenService):
                
                    async def optimize_production_service(self):
                
                      perf_gain = await self.upgrade_runtime() # +15-20% boost
                
                      latency = await self.doctrine_cache() # 20x latency drop
                
                      token_guard = await self.ai_feature_flags() # 0% wasted tokens
                
                      return ADR.record("ADR-018: Backward-compatible & Tested")
                
                  ⚡ MCP Multi-Agent Workflows & SDD Architecture
                  
                    Production-Grade

Measurable Business ROI

Code That Moves Key Business Metrics

I don't just write code — I optimize query plans, prevent infrastructure waste, eliminate manual processes, and guarantee system reliability.

+15–20%

Server Performance Gain

Achieved via runtime, dependency, and framework modernization on production Python/Django sales applications.

20x Faster

Endpoint Latency Reduction

Fixed heavy pagination bottlenecks and implemented custom parameter-based Doctrine result-caching.

90–100%

Manual Ops Automated

Eliminated manual challenge grading via AI webhooks, and automated diploma credential life cycles.

0% Waste

AI Token Cost Guardrails

Engineered granular feature flags in Python/Django preventing 100% of unwanted AI API token spend on disabled courses.

Engineering Showcase

Production-Grade Projects & Systems

Explore 5 featured systems demonstrating cloud-native GitOps, low-latency traffic shaping, high-concurrency ingestion, dual-engine AI simulation, and resilient full-stack architectures.

High-Concurrency Ingestion & IT Job Engine

Live in Production

DevATS — Multi-ATS Job Ingestion Platform

A high-throughput distributed crawler & developer-focused job board probing 600+ tech companies across Greenhouse, Lever, and Ashby concurrently without requiring API keys. Features strict IT-only job classification (isItJob), automated 45-day stale retention pruning, Ashby salary range parsing, Redis facet caching, and sub-millisecond PostgreSQL GIN index filtering.

Multi-ATS Slug Discovery: Heuristic slug generation stripping legal suffixes with concurrent 3-platform probing.
IT-Only Classifier Guard & Pruning: isItJob classifier rejects non-development roles at adapter boundary, with automated sweeping CLI scripts and endpoints.
45-Day Stale Retention Lifecycle (ADR/SDD 0005): Automated soft-deletion of expired roles preventing dead posting resurrection.
Redis Facet Cache & Salary Parsing (ADR/SDD 0001/0004): Caches top 100 facet tags for instant slicing and parses numeric compensation bands.

NestJS 11 Redis PostgreSQL (GIN) Prisma ORM React 19 TypeScript Tailwind CSS SDD / ADR 600+ ATS Probed

DATA FLOW & INGESTION PIPELINE Async Prober

Candidate Slug Generation

629+ companies cleaned & mapped

Concurrent ATS Probe

Greenhouse / Lever / Ashby

isItJob Guard & Salary Parser

Strict IT roles + numeric compensation

Redis Cache & PostgreSQL GIN

Sub-ms faceted query response times

AI-Powered Resume & ATS Intelligence

Live in Production

ATS MatchProof — Dual-Engine ATS Simulator

A high-speed, zero-account web application that compares PDF resumes against job descriptions with dual-engine AI scoring, skill gap detection, and instant bullet point optimization. Built with a strict privacy-first, zero-disk-storage in-memory stream processing model (bounded 200KB ceiling).

Privacy-First In-Memory Parsing: Resumes parsed in volatile RAM with strict 200KB bounded ceiling and zero disk persistence.
FastAPI & HTMX Architecture: Instant reactive responses without heavy frontend client-side bloat.
Dual-AI Matching Engine: Real-time keyword scoring, experience alignment, and actionable bullet rewrite generation.

FastAPI Python HTMX Tailwind CSS AI / LLM Integration In-Memory PDF (200KB) Bilingual (EN/PT)

ATS DUAL-ENGINE WORKFLOW Zero Storage

Multipart Stream Ingestion

PDF decoded in-memory bytes (200KB)

Dual-Engine AI Benchmark

Skill density vs Job Description

Instant Bullet Rewriter

Generates optimized impact points

Reactive HTMX Fragment Render

Zero frontend build step needed

Financial Accounting & Asset Management Engine

Live in Production

AMAE — Financial Ledger & Operations Platform

A production-grade, server-side rendered (SSR) web application connecting financial sponsors with field missionaries across Brazil. Automates recurring financial adoptions, tracks mission-field coordinates with geocoding, generates on-the-fly financial receipt PDFs, and provides full bilingual internationalization (English default and Brazilian Portuguese).

Bilingual Internationalization (EN / PT-BR): Dynamic locale switching in navbar, localized Django model choices and form labels, with full Pytest test coverage.
Decoupled Django Domain Modules: Isolated apps (missions, finance, pages) following clean architecture.
Automated Adoption Ledger: Multi-relational income/expense transactions with dynamic calculation rules.
High-Fidelity Automated Tests: Comprehensive Pytest test suite covering domain validations, statement generation, and language switching.

Python Django PostgreSQL Redis HTMX 2.0 Tailwind CSS 4 Bilingual (EN/PT) Clean Arch Pytest

DOMAIN ENTITY RELATIONSHIPS Django 6.0

Investor ➔ Adoption & i18n

Sponsors linked with EN/PT-BR locale

Geocoded Location Mapping

Latitude/Longitude coordinate tracking

Double-Entry Financial Ledger

Income/expense category balances

On-The-Fly PDF Statements

Automated monthly audit statements

Cloud-Native GitOps & SigNoz APM Platform

Live Multi-Tenant Cluster

K3s GitOps & SigNoz APM — Multi-Service Kubernetes Platform

A high-availability production cloud-native platform hosting Gabriel's complete project ecosystem on a multi-tenant K3s Kubernetes cluster. Implements declarative GitOps continuous delivery with ArgoCD (automated syncing, self-healing, resource pruning), unified OpenTelemetry APM observability with SigNoz (ClickHouse-backed distributed tracing, real-time container metrics, and centralized log aggregation) with automated SSL gateway termination.

Declarative GitOps with ArgoCD: Continuous delivery pipelines with self-healing, automated syncing, and immutable SHA-based image tracking across all namespaces.
Unified SigNoz OpenTelemetry APM: OpenTelemetry Collector daemonset ingesting distributed traces, host/container metrics, and stdout logs into ClickHouse for instantaneous multi-tenant flamegraphs.
Centralized Multi-Tenant Logging: Unified OTel log pipelines streaming container logs into SigNoz for instant query debugging and trace-correlated log inspection without SSH container access.
Automated Cluster Verification & Tag Pruning: Multi-arch CI builds with automated Docker Hub tag pruning routines (keeping latest + 3 tags) and host healthcheck verification suites.

Kubernetes (K3s) ArgoCD SigNoz OpenTelemetry (OTel) ClickHouse GitOps Docker Hub CI/CD

K3S GITOPS & SIGNOZ APM WORKFLOW SigNoz 360

Git Push & Multi-Arch CI

Native ARM/AMD64 Docker Hub builds

ArgoCD Declarative GitOps

Self-healing continuous delivery

K3s Multi-Tenant Cluster

DevATS, AMAE, ATSProof, EdgeShield

SigNoz OpenTelemetry APM

ClickHouse distributed traces, logs & metrics

Distributed Traffic Shaping & Low-Latency Gateway

Production Architecture

EdgeShield — Distributed API Gateway & Pure-Python Rate Limiter

A high-throughput, low-latency API Gateway and distributed traffic-shaping engine built in Pure Python 3.12 (FastAPI, AsyncIO, HTTPX) and atomic Redis pipelines. Protects upstream microservices against traffic surges and DDoS with zero external Lua dependencies, featuring an in-memory Circuit Breaker fallback for graceful degradation and native OpenTelemetry telemetry streaming to SigNoz.

Pure-Python Atomic Sliding Window (Zero Lua): Single-transaction Redis Sorted Set pipelines with monotonic ZRANK evaluation, eliminating check-then-act race conditions across horizontal replicas.
Dual-Tier In-Memory Circuit Breaker Fallback: In-process 3-state Circuit Breaker fast-failing to a bounded local memory limiter upon Redis failure, maintaining 100% gateway uptime without upstream flooding.
Native SigNoz APM & W3C TraceContext: Exports custom OTLP metrics (requests, blocked, redis_latency) to SigNoz Collector (:4318) and injects traceparent headers for end-to-end distributed flamegraphs.
RFC 7807 Problem Details & Tier Matrix: Enforces granular tiers (Anonymous, Free, Pro, Enterprise) via IP/API Keys, emitting standardized RFC 7807 responses with Retry-After and X-RateLimit-* headers.

Python 3.12 FastAPI Redis Pipelines Circuit Breaker OpenTelemetry (OTel) SigNoz Pure Python SDD & ADR

EDGESHIELD TRAFFIC SHAPING PIPELINE Python 3.12

Client Identity & Tier Policy

IP extraction / API Key tier mapping

Pure-Python Atomic Redis Pipeline

ZSET Sliding Window & monotonic rank check

Dual-Tier Circuit Breaker Fallback

Local in-memory sliding cache on Redis failure

Streaming Proxy & SigNoz Telemetry

W3C traceparent injection & OTLP metric export

Technical Competencies

Production Skills & Ecosystem

Battle-tested technologies and architectural methodologies used in production to build microservices, event-driven pipelines, secure APIs, and AI agentic workflows.

AI & Agentic

Model Context Protocol (MCP) Multi-Agent Workflows LangChain AI Tooling

Architecture

Spec-Driven Development (SDD) Architecture Decision Records (ADR) Cloud-Native GitOps Data Retention Lifecycles Microservices RESTful APIs Event-Driven Systems

Languages

Python TypeScript JavaScript PHP

Frameworks

Django FastAPI React NestJs Node.js Symfony

Databases & Caching

PostgreSQL (GIN) MySQL Redis (Cache & Queues)

DevOps & GitOps

Kubernetes (K3s) ArgoCD (GitOps) Docker GitHub Actions CI/CD Automation

Observability & Cloud

SigNoz (OTel APM) OpenTelemetry (OTel) ClickHouse AWS (EC2, Lambda) GCP (Compute Engine, GKE)

Career History

Production Engineering Experience

5+ years in the tech ecosystem with 3+ years delivering mission-critical backend features, legacy system modernization, and automated infrastructure at Full Cycle.

Full Stack Developer

Full Cycle • São Paulo, Brazil

Jul 2025 – Jul 2026

Context: Full Cycle is a leading Brazilian software engineering company and developer-education platform, focused on microservices and distributed systems. As a backend engineer on the internal product team, I built internal tooling and automation to eliminate manual work across the platform — from reusable admin components that accelerated content setup, to feature-flag systems that controlled AI API costs, to event-driven integrations automating student-facing workflows like credential issuance and challenge evaluation.

Accomplished a 90% acceleration in page section setup by engineering reusable Python/Django admin mixins, enabling instant deep-cloning of multi-relational sections.
Cut the cost of 100% of unwanted AI API token consumption on disabled courses by engineering granular feature flags in Python/Django with admin controls and conditional UI rendering.
Eliminated manual work 100% by automating challenge evaluation with a PHP/Symfony webhook integration to an AI-powered microservice.
Cut manual administrative effort by 90% with a PHP/Symfony API, automating the diploma credential lifecycle with comprehensive domain validation.

Python / Django PHP / Symfony AI Microservices Feature Flags Event-Driven Automation

Full Stack Developer

Full Cycle • São Paulo, Brazil

Jul 2024 – Jun 2025

Context: On the same team, I focused on performance and infrastructure reliability — upgrading and modernizing legacy Python/Django systems, optimizing database queries and CI/CD pipeline execution, and reducing infrastructure costs through more efficient service design.

Accomplished a 15% increase in server performance, by performing runtime, framework, and dependency upgrades to a production Python/Django sales application.
Reduced CI/CD pipeline feedback time by 20% by parallelizing test execution with Python/Django pytest-xdist library in Docker.
Decreased an endpoint's response time by 20x, fixing a pagination query bug in PHP/Symfony.
Cut infrastructure costs by eliminating an always-on worker pod, building a PHP/Symfony API that serves student-progress data on demand.

Python / Django pytest-xdist PHP / Symfony Docker CI/CD Optimization

Backend Developer

Full Cycle • São Paulo, Brazil

Jun 2023 – Jun 2024

Context: Earlier role on the same internal product team, where I accumulated Support Analyst and Development responsibilities — delivering backend features across both the Python/Django and PHP/Symfony sides of the platform while handling support duties in parallel. Focused on CRM integrations, asynchronous processing, student lifecycle automation, and test infrastructure modernization.

Removed 5 classes of exposed entry points - config, backup, source, dependency, and CMS-exploit paths - from a Python/Django app's public attack surface by blocking automated bot probes at the Nginx gateway.
Prevented sales lead loss from transient network failures by decoupling CRM lead sync into a Python/Django Celery task queue on Docker workers, with automatic retries.
Cut manual sync-recovery effort 90% with a PHP/Symfony HubSpot sync-schedule manager, auto-listing failed payment syncs with one-click admin retries.
Reduced student news-feed query latency up to 80% by caching complex multi-join chapter-release queries with a custom parameter-based Doctrine (PHP/Symfony) result-caching layer.

Nginx Gateway Celery Queues HubSpot API Doctrine Caching PostgreSQL

Software Analyst

Full Cycle • São Paulo, Brazil

Feb 2021 – May 2023

Context: Technical role focused on the analysis, support, and troubleshooting of software projects, including code analysis, error identification, and implementation of fixes. Provided support to students in resolving issues related to software development and project execution, requiring practical knowledge of programming and the technologies used in the courses.

Academic Background

Education & Specialized MBAs

A solid foundation combining software engineering, artificial intelligence, software architecture, and business administration.

Full Cycle

MBA in Software Engineering with AI

Computer Software Engineering • Advanced AI Agent Architecture, LLM Systems & Distributed Computing

Jul 2025 – Sep 2026

Full Cycle

MBA - Arquitetura Full Cycle

Computer Software Engineering • Microservices, Event-Driven Architecture (EDA), Clean Architecture & DevOps

Jan 2023 – Sep 2024

Ampli

Bachelor of Applied Science - BASc

Computer Software Engineering

May 2022 – May 2025

Union University

Master of Christian Studies

Theology, Ethics & Leadership

Dec 2018 – Nov 2024

Universidade Estadual de Feira de Santana - UEFS

Bachelor of Business Administration - BBA

Business Administration and Management, General

Feb 2004 – May 2009

Engineering Mindset

Why Engineering Teams Hire Gabriel

Core principles that guide my architectural decisions, code quality, and delivery speed.

Business Domain Understanding Before Code

I am a hands-on problem solver who values business domain understanding as much as technical execution. Combining software engineering with a Business Administration degree, I design systems that optimize business workflows, eliminate operational bottlenecks, and protect margin.

Spec-Driven Development & Uncompromising Tests

Writing clean, well-tested code is non-negotiable. I practice Spec-Driven Development (SDD) and document Architecture Decision Records (ADR) to ensure backward compatibility, clear contracts, and comprehensive test coverage across every service.

MCP Integrations & Multi-Agent Velocity

My approach is intentional: I leverage Model Context Protocol (MCP) integrations and multi-agent AI workflows to dramatically accelerate development velocity while keeping core engineering fundamentals razor-sharp.

Zero-Downtime Legacy & Microservices Modernization

Experienced in safely modernizing high-traffic legacy codebases and transitioning to decoupled microservices without breaking backward compatibility or interrupting active user traffic. Every migration is staged with clear metrics and validation tests.

Let's Connect

Ready to build something impactful?

I'm available for engineering roles, technical consulting, and high-impact full-stack contracts. Reach out directly through any channel below.

Based in Brazil (UTC-3) • Open to Remote Globally

Direct Email

gabrielcjr4@gmail.com

Send Email

WhatsApp / Phone

+55 75 99276-2777

Chat on WhatsApp

LinkedIn Profile

linkedin.com/in/gabriel-carneiro-jr

Connect on LinkedIn →

GitHub Repositories

github.com/gabrielcjr

Explore Repositories →

I build high-leverage full-stack applications & backend systems that scale, stay resilient, and automate manual workflows.

Code That Moves Key Business Metrics

Production-Grade Projects & Systems

DevATS — Multi-ATS Job Ingestion Platform

ATS MatchProof — Dual-Engine ATS Simulator

AMAE — Financial Ledger & Operations Platform

K3s GitOps & SigNoz APM — Multi-Service Kubernetes Platform

EdgeShield — Distributed API Gateway & Pure-Python Rate Limiter

Production Skills & Ecosystem

AI & Agentic

Architecture

Languages

Frameworks

Databases & Caching

DevOps & GitOps

Observability & Cloud

Production Engineering Experience

Full Stack Developer

Full Stack Developer

Backend Developer

Software Analyst

Education & Specialized MBAs

MBA in Software Engineering with AI

MBA - Arquitetura Full Cycle

Bachelor of Applied Science - BASc

Master of Christian Studies

Bachelor of Business Administration - BBA

Why Engineering Teams Hire Gabriel

Business Domain Understanding Before Code

Spec-Driven Development & Uncompromising Tests

MCP Integrations & Multi-Agent Velocity

Zero-Downtime Legacy & Microservices Modernization

Ready to build something impactful?

Project Deep Dive

Gabriel Carneiro Jr. — Resume / CV

Gabriel Carneiro Jr

Skills

Summary

Experiences

Education