Available for Global Remote Roles

Engineering high-performance products with AAA-grade quality from first commit to global launch.

I'm Lucas Monteiro. I work both as a Localization QA Tester (PT‑BR) for high-profile productions, including an official credit on Tekken 8, and as a Full-Stack Software Engineer building robust web applications, SaaS platforms, and secure software solutions with a strong focus on data protection. Available for global remote roles, and for freelance builds with businesses that need it done right.

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Global Remote Engineering Roles Freelance & Local Business Projects

Officially credited as Main Localization QA Tester (PT‑BR) on Tekken 8

Remote, Global

Full‑stack founder

Qavelix

Localization QA credit

Tekken 8

Featured Work

Two disciplines, one standard: ship it right.

From production SaaS infrastructure to AAA game certification, a track record of building and validating software that has to work under real-world pressure.

Sports-Tech Platform

NextCraque

Global Sports Career Platform & Opportunity Marketplace

NextCraque is a hybrid athletic career platform designed to democratize access to professional football, connecting aspiring players, from grassroots and amateur levels to youth academies, legal guardians, scouts, and professional clubs within a single secure, multilingual (PT‑BR/EN) ecosystem. Structured as an Athletic Career Web App with social network mechanics, it replaces the informal, high-risk world of amateur scouting with validated technical profiles, audited communication, and club-grade governance tools.

Player, Guardian, Scout, Club

User roles supported

Mandatory

Guardian validation for minors

PT‑BR / EN

Platform languages

Next.jsTypeScriptTailwind CSSNode.js+4

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Product Engineering

Qavelix

Full-Stack SaaS & Video Infrastructure

Qavelix is a scalable SaaS platform built end-to-end, from authentication and billing to an automated video processing pipeline capable of handling high-volume uploads with consistent, low-latency delivery. Designed and shipped the full architecture as the sole engineer, prioritizing maintainability, type safety, and performance at every layer.

3.5x faster

Video processing throughput

99.6%

Pipeline job success rate

< 1.2s

Core Web Vitals (LCP)

Next.jsTypeScriptTailwind CSSNode.js+4

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Healthcare Web Platform

Gabinet Terapii Naturalnych

Medical Authority, Local SEO & Automated Booking

A secure, high-performance Next.js platform for a Warsaw-based natural therapy practice, built to establish medical credibility, win local search, and convert visitors into booked patients through automated Booksy scheduling.

100%

Automated booking coverage

< 1.0s

Core Web Vitals (LCP)

A+

Security headers grade

Next.jsTypeScriptTailwind CSSCloudflare+3

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Localization QA

Tekken 8

Main Localization QA Tester (PT‑BR)

Served as the Main Localization QA Tester for the Brazilian Portuguese (PT‑BR) release of Tekken 8, a AAA fighting game title, ensuring linguistic accuracy, cultural relevance, and full text integrity across the PT‑BR build. Work was recognized with an official credit in the shipped title for contributions to localization quality, build stability, and release readiness.

Yes

Official title credit

1,000+

Strings & test cases reviewed

PT‑BR

Localization track

Localization QALinguistic & Cultural AccuracyText Truncation & Encoding QARegression Testing+2

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Freelance Services

Custom development for businesses that need it done right.

Alongside full-time remote engineering, I take on select freelance projects, building high-performance websites, booking systems, and custom web apps for small businesses, agencies, and clinics.

Small Businesses

Local & independent businesses

Fast, professional websites that make a small business look established, built to load instantly, rank well, and convert visitors into customers.

High-performance marketing & brochure websites
Mobile-first, SEO-ready foundations
Contact, quote, and lead-capture forms
Ongoing support and easy content updates

Marketing Agencies

Agencies & creative studios

A reliable dev partner for agencies that need pixel-perfect builds delivered on deadline, from campaign landing pages to full client sites, without the back-and-forth.

Landing pages built from Figma with zero drift
Multi-client site builds under white-label workflows
Fast turnarounds for campaign launches
Clean, handoff-ready code for in-house teams

Medical & Wellness Clinics

Clinics, practices & wellness studios

Modern, trustworthy digital experiences for healthcare and wellness providers, with the booking flows and reliability patients expect.

Custom appointment & booking systems
Patient-friendly, accessible interfaces
Secure intake forms and integrations
Polished, credibility-building design

Have a project in mind?

Open to select freelance engagements alongside remote full-time work. Let's talk about what you need.

Start a Project

Technical Expertise

A full-stack toolkit, tested at scale.

Capabilities spanning interface engineering, backend systems, media infrastructure, and the localization QA discipline of AAA game development.

Frontend Engineering

Building fast, accessible, pixel-precise interfaces.

ReactNext.jsTypeScriptTailwind CSSFramer MotionReduxAccessibility (WCAG)Responsive Design

Backend & Systems

Designing reliable, scalable server-side architecture.

Node.jsPythonExpressPostgreSQLRedisREST & GraphQL APIsDockerCI/CDSystem DesignApplication Security

Video & Media Pipelines

Automated processing at scale for media-heavy products.

FFmpegTranscoding PipelinesAdaptive Bitrate StreamingJob QueuesChunked UploadsMedia Storage (S3-compatible)

Quality Assurance & Testing

AAA-grade rigor applied to software of every kind.

Manual & Exploratory TestingRegression TestingLinguistic & Cultural QALocalization QATest Case DesignJest / Playwright

Experience

Built for remote, built for global teams.

A track record of delivering high-impact work asynchronously, across time zones, without compromising on standards.

2025 — Present

Founder & Full-Stack Developer

Qavelix / Freelance

Founder of Qavelix and freelance developer, building SaaS products and custom digital solutions for small businesses and professionals, while continuously deepening my advanced Full-Stack Python studies.

Qavelix: founder and engineer responsible for the end-to-end development of this SaaS platform, focusing on clean architecture, automation, performance, and robust security.
Freelance & Client Projects: independent work creating custom modern websites and platforms for small businesses and professionals, such as the web platform developed for Dr. Jurij Tokar's clinic in Warsaw.
Lifecycle & Studies: managing the full product lifecycle (architecture, implementation, deployment, security), while continuously deepening advanced skills through Full-Stack Python development studies.

2023 — 2024

Main Localization QA Tester (PT‑BR)

Tekken 8, Localization QA

Served as the main Brazilian Portuguese (PT‑BR) localization QA tester on Tekken 8, ensuring linguistic accuracy, cultural fit, and text integrity across the full PT‑BR build ahead of global console certification.

Reviewed all in-game text, menus, and subtitles for linguistic accuracy and natural PT‑BR phrasing.
Checked truncation, encoding, and formatting across every screen to keep the PT‑BR build release-ready.
Earned an official shipped-title credit for contributions to localization quality and release readiness.

2022 — 2023

Full-Stack Python Development, Training & Freelance Work

Self-Directed / Freelance

Deepened technical foundations through intensive Full-Stack Python training, while taking on freelance software and translation projects to apply new skills in real-world contexts.

Completed structured Full-Stack Python development training, covering backend architecture, APIs, and databases.
Delivered freelance software projects for small clients, applying newly acquired Python and full-stack skills.
Took on freelance translation work, sharpening the linguistic precision later applied to AAA localization QA.

Comfortable across time zones, async workflows, and distributed teams.