Alexandre Augustus
Verified Expert in Engineering
JavaScript Developer
São Paulo - State of São Paulo, Brazil
Toptal member since November 11, 2019
Alex is a CTO and lead developer with product and leadership skills and several years of hands-on experience and technical expertise. This hard-to-come-by skillset allows him to translate business and user needs while overcoming technical challenges to build excellent products. Alex helped PagSeguro transition into a unicorn company by transforming their digital wallet app into a fully digital bank. He has also served as the CTO of multiple startups through Toptal.
Portfolio
Experience
- JavaScript - 12 years
- Android - 11 years
- iOS - 7 years
- React Native - 7 years
- React - 7 years
- CTO - 7 years
- Node.js - 7 years
- Next.js - 5 years
Work Experience
CTO | Lead Engineer
Freelance Clients
- Led end-to-end architecture and development of AI-powered platforms, integrating LLM agents, real-time streaming pipelines, and multi-service back ends.
- Managed and mentored engineering teams of 5-30 developers across global time zones.
- Designed and deployed high-performance applications at scale, including mobile apps with millions of users.
CTO | Lead Engineer
Orsy Inc.
- Led the team to develop a live-streaming social network using React Native.
- Oversaw all the development, mentored, and helped with the most challenging parts of the application.
- Determined critical business decisions alongside the CEO.
CTO | Lead Engineer
Foodvine
- Led the technical team to develop a food delivery and social network app.
- Motivated and managed the development team to deliver top quality and performance.
- Translated business needs into technical requirements while being a focal point to product and technical decisions.
Lead React Native Developer
Belk
- Led the development of an eCommerce app using React Native.
- Created everything from scratch while connecting to a complex API that was not mobile-friendly.
- Built middleware APIs to make it more mobile-friendly through Firebase cloud.
React Native Developer
Blue Light Holdings, Inc
- Improved app performance, created social sharing features, and more.
- Integrated with Instagram and Facebook. Improved video performance.
- Created a draggable clock timer component to help users time their exercises.
React Native Architect
Home City Ice (via Toptal)
- Reviewed and improved the code.
- Coded the architecture.
- Recommended improvements to the React Native app.
- Guided and instructed developers.
Lead Developer
Crefisa | Credit, Finances, and Investments
- Led a team of 12 developers to build a digital bank from scratch.
- Created a lead product team within the company and assigned employees to each of the lacking product areas.
- Mediated among business, product, and technical needs, acting as a focal point for the entire mobile app.
- Built integration systems to work with existing apps and services.
- Helped estimate and prioritize product and technical tasks.
Mobile Tech Lead
Original Bank
- Led a team of ten mobile developers in the creation of a digital bank app.
- Oversaw the React Native training session for the mobile team.
- Created development guidelines for the mobile team.
- Spearheaded the development of multiple apps that supported the core digital bank services.
- Improved the App Store review rating from 3.5 to 4.7 in two years.
- Integrated React Native with Twilio using the backend as a gateway.
Senior Mobile Developer
PagSeguro UOL
- Developed a digital wallet app.
- Transformed the digital wallet into a fully digital bank app.
- Created credit card app features.
- Developed the main bank account's app features.
- Constructed multiple MVPs to validate business ideas.
Full-stack Intern
VISIUM
- Developed a field service app for a big internet company.
- Created a modem scanning app.
- Maintained the app's API C# services.
- Created GPS- and map-focused apps.
Independent Developer
Freelance Work (Apps for the Google Play Store)
- Developed the SnapSave Pro app.
- Constructed the app called WhatsApp Offline.
- Developed and maintained proprietary apps.
- Researched users and developed products to suit their needs.
- Constructed an image-editing app.
Project History
PagBank (4.8 Star Rating in the App Store)
Sales — PagSeguro (4.7 Star Rating in the App Store)
Original Bank
Belk eCommerce
https://apps.apple.com/us/app/belk/id673347869Foodvine (Social Network)
Foodvine allows users to browse authentic recipes that suit their dietary needs, such as keto, gluten-free, vegan, weight-loss, or hop in a cooking class and interact with step-by-step instructions on cooking global flavors from the community.
Orsy (Live Streaming Social Network)
With Orsy, anyone can become a citizen journalist simply by capturing content that gives the community a front-row seat and insight into current events or the news of the day, and the community can see any event from multiple citizen journalist perspectives, rewarding those who upload the compelling content.
Raven Health (Mobile and Web App)
http://ravenhealth.comOpenEnglish (Learning Web and Mobile App)
Education
Bachelor's Degree in Computer Science
UNICAMP | The University of Campinas - Campinas, Sao Paulo, Brazil
Exchange Studies in Computer Science
Roger Williams University - Bristol, RI, USA
Skills
Libraries/APIs
React, React Redux, Redux-Saga, Apiary API, Django ORM, Node.js, REST APIs, Salesforce API, MobX, Stripe, Google Maps API, Vue, Instagram API, Interactive Brokers API, OpenAI API, PySpark, TikTok API, Binance API, Google Maps, ArcGIS, Core Audio, API Development, RxJava, Web3.js, WebRTC, RxJS, FusionCharts
Tools
Redux Thunk, GitHub, Expo, Bubble, Google Analytics, ChatGPT, React Apollo, Prisma, Trello, Sentry, Docker Compose, MultiCharts, GetStream, Open Broadcaster Studio (OBS), Apache Airflow, BigQuery, Google Cloud Composer, Google Kubernetes Engine (GKE), CircleCI, Claude, Claude Code, High-performance Cluster Manager (HPCM), Amazon EKS, Amazon Transcribe, Asana, Zeplin, Figma, Terraform, WebStorm, Git, Xcode, Android Studio, Visual Studio, Mailchimp, Agora
Languages
JavaScript, Java, Kotlin, C++, Python, SQL, PHP, HTML, TypeScript, GraphQL, CSS, Sass, HTML5, Pine Script, Snowflake, Rust, C, Objective-C, Swift, C#, Go, ABAP
Frameworks
React Native, Redux, Django, Next.js, Express.js, Spring Boot, Bootstrap, Tailwind CSS, NestJS, Laravel, Ruby on Rails (RoR), Electron, Flask, CodeIgniter, Serverless Framework, Rx
Paradigms
REST, Agile, Functional Programming, Asynchronous Programming, Mobile Development, Scalable Application, DevOps, Requirements Analysis, Desktop App Development, Gamification, Cross-platform, Microservices, Model Context Protocol (MCP), Parallel Computing, HIPAA Compliance, Microservices Architecture, Back-end Architecture, Automation, Azure DevOps, High-performance Computing (HPC), UX Design, Model View Controller (MVC)
Platforms
MacOS, iOS, Android, Linux, Windows, Firebase, Amazon Web Services (AWS), WordPress, Google Cloud Platform (GCP), Mobile, Kubernetes, Docker, Azure, Vercel, tvOS, Mapbox, WooCommerce, Replit, Salesforce, Desktop, AWS Lambda, BigCommerce, SharePoint, Twilio, Shopify, Heroku, Blockchain, Embedded Linux, Bitrise, Oracle Integration Cloud (OIC), SAP ABAP
Storage
MySQL, PostgreSQL, MongoDB, Cloud Deployment, Elasticsearch, Amazon DynamoDB, Redis, Google Cloud Storage, SQLite, ClickHouse, PostGIS, Alibaba Cloud, Realm
Industry Expertise
Project Management, Social Media, High-frequency Trading (HFT), Trading Systems, Marketing
Other
Leadership, Technical Leadership, Team Leadership, CTO, APIs, CI/CD Pipelines, App Store, Google Play Store, WiFi, Smart Cameras, Full-stack Development, Architecture, Back-end, Front-end, Project Planning, Product Strategy, Metrics, Fintech, AWS Cloud Architecture, Software Architecture, Video Streaming, Full-stack, eCommerce, Webhooks, Google Tag Manager, Payment APIs, Machine Learning, Product Owner, Technical Product Management, Bluetooth, OpenAI GPT-4 API, Artificial Intelligence (AI), Natural Language Processing (NLP), SaaS, System Architecture, Chatbots, Community Growth, Web Development, Digital Payments, Online Payments, B2B Wallets, Serverless, IT Management, Software Engineering, Engineering Management, Delivery Management, Push Notifications, Location Tracking, Apollo, TV Broadcasting, Broadcasting, TV, TV UI, Over-the-top Content (OTT), OpenAI GPT-3 API, Supabase, Subscriptions, Hiring, Investments, Charts, Data Scraping, Web Scraping, OpenAI, Proxies, Instagram, Automated Trading Software, Trading, Trading Bots, Fractional CTO, Algorithmic Trading, Cloud Architecture, Content Delivery Networks (CDN), Web Applications, Scalability, Large Language Models (LLMs), API Integration, Text-to-Speech (TTS), ElevenLabs Solutions, Open Broadcaster Software (OBS), Geospatial Data, GPU Computing, Electronic Health Records (EHR), Electronic Medical Records (EMR), System Integration, Enterprise Architecture, OpenStreetMap, Data Visualization, Backtesting, Data Analysis, Performance Optimization, Prediction Markets, Backtesting Trading Strategies, Quantitative Finance, Quantitative Modeling, Agentic AI, Agentic RAG Systems, Workflow Automation, Mobile Apps, Fraud Prevention, Payments, Reliability, Engineering, Identity Verification, Audio Capture, Code Signing, Crash Reporting, IPC, Data Science, Real-time Audio Processing, Software Design, Workflows, Healthcare Software, IT Security, Security Compliance, SOC 2, PHIPA, HIPAA, Protected Health Information, WebSockets, Real-time Data, AI Development, Simulation Orchestration, OpenTelemetry, Simulations, Containers, Simulation Engines, Agriculture, TimescaleDB, Desktop App, FastAPI, Project Consultancy, Infor ION, Prompt Engineering, Retrieval-augmented Generation (RAG), Amazon Bedrock, ServiceNow, Workday, App UX, App UI, Product Design, Product Management, Tech Sales, Crypto, Smart Contracts, VoIP, Transportation & Logistics, Embedded Software, LangChain, Web3, Maps, Social Networks, Polygon, GetStream.io, Chief Product Officer (CPO), RAG Architecture, Amazon Bedrock AgentCore, SAP
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