Vithorio

Owner of the company, working as a consultant, has been providing  services to businesses and private entrepreneurs, from hourly services for bug-fixing, workshops, analysis, and pure development.  He guides modularization efforts, with architecture proposals, to solve and alleviate pain points.

• Handling many freelance contracts to companies he worked with previously, but also gathering new clients from recommendations
• Presented mini-workshops about Android Lifecycle and Jetpack Compose

Initially hired as Android-only, later became a solo developer for Android and iOS, most of his activities were small iterations of the product, with the most at payments or promotional features.  Discovered an anti-fraud system’s early corruption, that would eventually destroy 6 years’ worth of databases, the presented report had validation of the issue, in which platforms and systems, and corrosion estimate.

• Migration in payments system to support PSD2/3DS2 (initially supporting Adyen+WorldPay) without downtime, and keeping legacy system intact
• Refactor the login/session as a new module, removing known app-only vulnerabilities and supporting the new, safer, auth system API
• Implemented 6 new payment methods, worldwide or local reach, with dynamic components switching triggers, cashback, and similar features
• Legacy Java/Obj-C migration to Kotlin/Swift to remove legacy vulnerable/deprecated libraries and match the rest of the codebase

Created a new mobile experience from the ground up, replacing the old hybrid app with a more friendly, performant, and extensible native app. The team created a complete Design System and a Design System Component Library along with the Architecture to move it forward.

• Highly dynamic UI (Layout and components hierarchy where defined per request)
• Multiple visualization strategies (list/board), requiring any data flow to be centralized and reactive
• Defined the Design System with the design/UX team, and implemented the Components per definition in the Design System modules, with snapshot testing for each component variation
• Experience-first, feature-by-feature product reevaluation, release, and experimentation achieving increased satisfaction of our early access clients with each iteration
• Created the PR templates and CI workflows, in GitLab, with Danger Kotlin automated code review reports. Its success got replicated in other stacks

Worked as a consultancy resource to many financial businesses, ranging from well-established banks to vivid startups. Implemented a retro-compatible Biometric Storage Layer for Support Library 28

• Many stability and bug fixes in a few banking apps
• Retro-compatible Biometric Storage Layer for Support Library 28, based on modern AndroidX’s Biometric solution, almost 1:1, so forward-proof to ease a future migration, used by a giant LATAM Bank

This project was an MVP for smart Personal Finances Management. In partnership with the third largest traditional Brazilian bank, their goal was to bring innovation and know-how to their field.

•  Initially hired to teach 2 Android interns, while rewriting the last 3 months of a failing ongoing project, and squeezing our next deliveries to meet its PoC deadlines, we reached, the full feature set, months earlier than the bank’s expectations
• Officially led 5 developers in native Android & iOS (Java & Swift, MVVM), providing tech training and mentorship;
• Led the whole B2B Integration, from Backend APIs to Mobile, with emphasis on security
• As per our security analysis routines, I hacked the bank’s new Connectivity SDK and exposed detailed reports to the bank, fixing major vulnerabilities not caught by their security team and leading to a 2.0 protocol version we created in partnership
• Wrote a Graphs and Charts library, using pure Android Canvas to achieve the custom shapes and animations expected in our design system. 8 reusable components were made

Hired to develop a chat app for Android, heavily inspired by WhatsApp/Telegram, but also had enterprise-level features, even more features than WhatsApp Business would eventually launch later. They had a PoC already developed but wasn’t up to their own standards, so the team finally delivered it from scratch.

• Custom video layouts for different kinds of video calls, using SurfaceTexture and OpenGL low-level primitives to stack and shape live video
• WebRTC, Rest, and WebSockets combined to deliver real-time communication, audio, and video features
•  Automated WebRTC’s nightly builds, directly from Chromium’s source, rebuilding Android and iOS, and running basic tests or alerting in case something broke
• Wrote a “Session Recorder” and got really close to QA to achieve 99,9% crash-free sessions
• Created a CI pipeline with multi-stage deployment (dev, QA, alpha, beta, stable), based on Git Tag versioning, using Slack Bot for Approval/Reject, meaning we had a single source of truth to our versioning and deployments

Mostly Android and iOS, but had done tasks in Python, JS, and PHP, and had a big impact in DevOps. The main projects were related to achieving modernization of Education, but they had a wide range of industries in parallel, in short amounts. He had some minor unofficial leading roles.

• Optimized Regexes for data manipulation, effectively reducing each processing request from 3-15s to 10-50ms
• Troubleshot and fixed memory leaks in most legacy projects
• Improved/reworked safety measures, especially authentication in most projects, explaining each flaw and tackling the solutions
• He did a few workshops to help the team migrate from PHP to Node, adopt Docker to improve the workflow and onboard new devs, and quick-start experimenting with Python for Machine Learning
• He wrote many features, in many projects, in many stacks, backend, web frontend, native mobile, hybrid mobile, many times learning new stacks each week
• Implanted a few CI pipelines in Jenkins and AWS CodePipelines

Technologies:  Android, iOS, Python, JS, PHP, DevOps, Node, Docker, Machine Learning, Jenkins, AWS CodePipelines, Django, Express, Flask, Ruby on Rails, Laravel, AWS, GCP, MongoDB, MySQL, SQL Server, Angular, jQuery, React, React Native, WordPress, HTML, CSS

Built a Delivery app, both Consumer and Driver’s apps in Kotlin, heavy geolocation, and real-time updates, somewhat similar to Rappi and Uber Flash. Maintenance for offline-first Warehouse management app, thousands of clients with geolocation/routing, consignment, stock, and auditing. Maintenance is a simple chat app. Implemented the mobile CI/CD pipeline automation, from Git versioning, Slack notifications, and finally multi-stage deployments. Those concepts were later applied to the whole stack; creating a modular commons framework) that was used internally, even after his departure, including new projects, with a private fork, until Jetpack’s Lifecycle V2 release came.

• Co-created (github.com/lucasmpaim/EasyRest) iOS lib initial version, which was used by many projects and is still used today in other companies in the local area
• Presented many new technologies to our team, most notably getting adoption to Kotlin, Fastlane, Docker, Bitrise, Zeplin, and Sentry, with huge success
• Took ownership to re-architect the whole offline-first solution, with the app already going Beta, while training all members in advanced concurrency and the issues with their solutions
•  Achieved reduction of ~90% of ANRs and OOMs, caused by memory leaks, concurrency, or lifecycle issues, that plagued our legacy apps, also increasing crash-free sessions as a side-effect

Technologies:  Kotlin, CI/CD, Git, Slack, Jetpack, GitHub, Fastlane, Docker, Bitrise, Zepplin, Sentry, AWS, SQL Server, Android, iOS, DevOps, Open Source

• Android Developer for Clubhouse (2015)
• Android Internship at AGIVIS (2015)
• Freelance Android Developerat Charneira Supernova (2014)
• Android Internship at DevMaker (2013-2014)