Principal Software Engineer | AI Specialist | Cloud Infrastructure & AWS Expert
Full-Stack TypeScript developer: Node, Angular, React, and React Native. AWS infrastructure, AI-Driven apps, Spec-Driven Development, and TDD.
About me
I'm João, son of a single mom, and I grew up more inside the computer than outside, hooked on logic, strategy, and business from early on. At 11 came the ADHD and giftedness diagnosis, and it took me a while to understand why I thought differently from everyone else; for a while it left me feeling alone, until it clicked that it was exactly what made me unique. I've never accepted anything just because, and it's that stubbornness that drives my urge to pry things open and see how they really work. I married young, because waiting never sat well with me, and today I juggle code, company, and family all at once, as co-founder of a US real estate startup.
I build complete systems from the absolute ground up to production: specification, prototyping, architecture, development, DevOps, infrastructure, and deployment.
See my specialties →I use AI as a tool, not a crutch. I work with spec-driven development, agentic workflows, skills, rules, hooks, and plenty of documentation and context.
See my toolkit →My specialties
Experience
From freelance to co-founder, hands on the code the whole way, through marketing tech, media, and now PropTech.
Confidencial · PropTech
I co-found and build an AI platform for the US real-estate market, with AI at the core of the product and present in every feature. Every line of the code is mine.
While we're in our time-to-market phase, I can't go into product details publicly yet.
adMixt
Senior Full-Stack Developer specialized in modernizing legacy systems through innovative architectures and from-scratch development.
I develop modern, modular solutions using pure Vanilla JavaScript, creating complete features from the ground up without external dependencies and seamlessly integrating them into 20+ year legacy PHP environments. My expertise lies in building bridges between contemporary technologies and established systems, implementing scalable architectures that respect existing environment limitations.
I transform complex technical challenges into innovation opportunities, developing reusable components, dynamic interfaces, and advanced functionalities that elevate user experience without compromising core system stability. I apply modern software engineering principles to create clean, testable, and maintainable code within legacy ecosystems.
Key Technologies & Expertise: JavaScript Vanilla, Modern Web Architecture, Legacy System Modernization, Component-Based Development, Custom Framework Creation, PHP Integration, Database Optimization, Code Refactoring, Progressive Enhancement
Howhow
As LT at Howhow, I lead a dedicated team of technology experts focused on innovating in the influencer marketing sector. Our mission is to develop a revolutionary platform that effectively connects brands with influencers, supported by advanced technologies such as AI, NLP and data analysis. This commitment to innovation allows us to offer solutions that not only meet but exceed our clients' expectations, delivering personalized and high-impact results.
Biggest challenge:
The biggest challenge was to develop a multi-user platform with several levels of access, capable of managing complex marketing campaigns with several influencers simultaneously, involving several stages such as accepting proposals, signing contracts, sending and approving content, reviewing and much more. This complex system required a robust and flexible architecture, as well as an intuitive interface that would allow users to easily navigate these multifaceted processes without compromising efficiency or security.
Our gain:
Overcoming this challenge brought significant benefits to Howhow's clients. With our advanced platform, brands can now manage influencer marketing campaigns more efficiently, monitoring each stage of the process in real time and ensuring compliance and content quality. This has resulted in significant campaign optimization, more effective influencer marketing and a better return on investment. The ability to manage several campaigns and influencers simultaneously, with different levels of access and control over the process.
By delivering the MVP of the platform we can drive it to become a Serie A
Artweb · João Pster
(This is a fixed-term project for a client of my company)
Position: Technical Leader
Team: 2 Designers and 6 Developers
Technologies: React, React Native, Angular, Flutter, GCP, Firebase, Generative AI
Summary:
As Technical Lead at Artweb, I led a highly talented team of 2 designers and 6 developers in the creation and integration of 5 innovative applications, encompassing 2 applications for television, 2 for web and 1 for mobile devices, all aimed at enriching the Artweb system, similar to Netflix, but focused on the exhibition of works of art. Over the course of 1 year and 4 months, our self-managed team produced more than 200,000 lines of code, adopting agile methodologies and tools such as Git Flow, Jira and BitBucket, and implementing a range of advanced technologies that included React, React Native, Angular, Flutter, Google Cloud Platform (GCP), Firebase and Generative Artificial Intelligence.
Biggest Challenge:
The main challenge faced was to achieve fluid integration between the various applications and technologies, ensuring a uniform, high-quality user experience across different devices, while keeping the platform scalable to support the expectation of over 500,000 users already in the first year. This challenge required an innovative and collaborative approach to overcome the technical complexities and ensure interoperability between the different solutions.
Customer Gain:
Overcoming this challenge not only strengthened Artweb's technological infrastructure, but also redefined the way the public interacts with digital art, providing unprecedented access to high-quality artworks through an intuitive interface. The project raised the bar for the digital presentation of art, increasing accessibility and artistic appreciation, resulting in a platform that not only met but exceeded the client's expectations in terms of user engagement and reach, establishing a new paradigm for the digital cultural experience.
Independent
Technology teacher teaching React, React Native, Angular, Node, Express, Nest, GCP, AWS, Azure and several other technologies to +100 students throughout this period.
João Pster
As a Tech Provider at João Pster's company, I lead several teams of highly qualified technology professionals (I also act as a programmer and teacher) on various projects, committed to driving our clients' success.
I have been active in all the projects below as Technical Lead and Developer, using my own Hands-On leadership methodology.
We specialize in software development, upgrading and enhancing systems and applications, IT outsourcing and technology consulting.
Graduates of Trybe, the largest programming school in Brazil, our professionals not only have exceptional technical skills, but are also experts in soft skills such as teamwork, leadership and time management. At João Pster, we pride ourselves on offering personalized and tailor-made solutions, adapted to the specific needs of each client, guaranteeing a significant impact on their business.
Howhow · João Pster
As CTO of Howhow, I have the privilege of leading a team of technology experts who are fully committed to making a difference for our clients. We are at the forefront of digital innovation, with a focus on building a revolutionary influencer marketing platform that connects brands to influencers efficiently and effectively.
Our work is powered by cutting-edge technologies, including artificial intelligence (AI), natural language processing (NLP), and advanced data analytics. These capabilities allow us to create high-quality solutions that go beyond our clients' expectations.
In every project we undertake, our team works tirelessly to develop customized solutions designed to meet each client's unique needs. Our goal is always to generate a significant and lasting impact on your business operations.
At Howhow, we pride ourselves on our ability to innovate and adapt. We are always looking for new ways to improve and extend our reach in order to continue to provide the best solutions for our clients.
AfterSale
(This is a fixed-term project)
Position: Senior Front-End Developer
Team: Working in a self-managed team
Technologies: React
Summary:
As a Senior Front-End Developer at AfterSale, I was tasked with creating dynamic and innovative front-end solutions to enhance the company's reverse logistics platform. Working in a self-managed team, I made extensive use of React technology to develop interfaces that not only improved the user experience, but also the overall efficiency of the platform, contributing significantly to the optimization of reverse logistics processes.
Biggest Challenge:
The most significant challenge I faced was implementing a dynamic and highly intuitive user interface at a crucial stage of the reverse logistics process, within a pre-existing and complex system. The difficulty lay in the need to integrate modern, agile front-end solutions into the legacy code, while keeping the system's stability and performance intact. This challenge required not only a technical mastery of front-end technologies, but also a capacity for innovation and creativity in interface design, as well as a deep understanding of the limitations and characteristics of the legacy system.
Customer Gain:
Successfully overcoming this challenge resulted in a substantial improvement in the user experience within the reverse logistics platform, making the process more intuitive, efficient and less prone to errors. This not only increased end-user satisfaction, but also optimized AfterSale's internal operations, leading to more effective management of reverse logistics processes. The implementation of these dynamic, user-friendly interfaces has translated into tangible operational gains for the company, reinforcing its position in the market and highlighting the importance of innovative front-end solutions for the continuous improvement of reverse logistics services.
Digital Republic
Position: Mid Front-End.
Team: Collaboration with multidisciplinary and self-managed teams
Technologies: Next.js, Angular
Summary:
At Digital Republic, I worked as a Technology Consultant and Senior Front-End Developer, getting involved in innovative projects focusing on emerging technologies such as Next.js and Angular. My experience included collaborations with renowned entities such as Fundação Bradesco and RG/A, where I played a crucial role in developing customized, efficient and high-impact technological solutions. Working alongside multidisciplinary teams, I employed a combination of technical and analytical skills to ensure the delivery of quality projects in line with client expectations and needs.
Biggest Challenge:
The most significant challenge was the development of a highly dynamic and complex website for RG/A, characterized by an innovative layout, unique animations and an extensive structure that included a blog. The project required both the website and the blog to be modifiable via a no-code platform, which provided the necessary page structure in JSON format, with each blog post requiring a personalized page defined by a distinct JSON. To overcome these challenges, I adopted a strategic approach, segmenting the project into modular components that I called "Bricks", and developed each one following the Atomic Design methodology. This strategy allowed for clear documentation and efficient implementation, resulting in the successful delivery of the project in half the planned time.
Verzel
Position: Mid Front-End
Team: Collaboration with multidisciplinary and self-managed teams
Technologies: Angular, React, Node
Summary:
While at Verzel, I held the roles of Technology Consultant and Senior Front-End Developer, getting involved in challenging projects that utilized Angular and React. One of my notable contributions was the development of an advanced chatbot for Mutant, aimed at significantly improving communication and the user experience. I worked closely with multidisciplinary teams, applying a mix of technical and analytical skills to ensure that the solutions delivered were perfectly in line with the clients' needs and objectives, excelling at creating innovative solutions that boosted the functionality and efficiency of projects.
Biggest Challenge:
Developing the advanced chatbot represented a significant challenge, mainly due to the need to integrate it seamlessly with the client's existing systems, while ensuring a fluid and intuitive user experience. The project required an in-depth understanding of the capabilities of Angular and React, as well as a creative approach to implementing AI functionalities that would enable the chatbot to understand and respond to users' needs effectively.
Independent
Working on +50 small projects that are summarized here, I played a key role in the development and leadership of multidisciplinary teams in various projects of varying sizes and scopes. With extensive experience in technologies such as React, Angular, Vue, React Native, Express, Node, Django, WordPress and even Wix, I was responsible for creating interfaces and UI/UX, applying my knowledge of product design, user experience and application architecture.
Throughout my career, I have interviewed, assessed and hired exceptional talent for our teams, always adopting agile methodologies such as SCRUM/KANBAN, together with tools such as Jira and Slack, to ensure successful and efficient projects.
I developed important skills during this period, including negotiation, teamwork, leadership, communication, assertiveness and providing constructive feedback. In addition to my work at Pster, I've freelanced and provided services to various marketing agencies, such as Really, and worked on confidential projects, such as Detran de SC.
Although I'm presenting just a few samples of my work, my experience covers a wide range of projects of different scales and challenges, always seeking to deliver innovative, high-quality solutions for our clients.
Self-employed
I've developed mods in .NET with C# for various games based on Harmony X technology, I had a store to sell plugins and mods called CastCodes, I've worked in international teams and managed virtualized servers in AWS, GPC and Azure.
I already have over 11,000 hours developing in this stack.
Interfaces built with care.
Built to scale, run on AWS.
AI, used the right way.
Good software rarely comes from clever abstractions. It comes from the dull work of clear boundaries, typed contracts, and tests that run. I build for whoever touches the code two years from now, not for today's excitement.
See what I've built →Writing is how I find out what I actually understand. I publish long pieces on tooling, architecture decisions, and the tradeoffs that don't fit in a tweet. If one post saves you an afternoon of debugging, that's enough.
Read the blog →Hours measured, not guessed. WakaTime logs all of it on its own: languages, projects, editors. The history starts in January 2026, when I began tracking.
Before that I'd been coding since 2020, just not measuring. At 8h a weekday, that's roughly 12,480 hours + 893h = ~13,373h.
View WakaTime →Open source
Personal projects and open-source contributions. Tools with people on the other end actually using them.
An anti-vibe-coding, agentic AI workflow that brings engineering rigor to any project, language or framework. Model-agnostic, with a native Cursor plugin.
Teams-first multi-agent orchestration layer for Claude Code. I contributed skill improvements, hooks, and workflow integrations.
A Rust CLI proxy that cuts LLM token usage by 60-90% on common dev commands. Single binary, zero dependencies.
My toolkit
Broken down by category: languages, frameworks, and the AI tools that changed how I work.
"The best tech stack is the one your team can ship with confidently and maintain without dread."
Building software since 2020.
From marketing tech to media and PropTech.
Portuguese, English, and Spanish.
I'm always happy to talk architecture, AI engineering, or what you're building, whether it's a project, a role, or just a good technical problem.