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Horaci Cuevas
Verified Expert in Engineering
Large-scale Projects Developer
Barcelona, Spain
Toptal member since May 5, 2017
Bio
Horaci is a passionate engineer who enjoys building products that users will love. With a history in entrepreneurship, management, back-end engineering, and now mobile engineering, he's able to understand and architect products from top to bottom and provide the best solutions for his clients.
Portfolio
Jobandtalent
Android, Kotlin, Jetpack Compose, Spring Boot, Kubernetes, Android Studio...
Fleksy
C++, SDKs, Amazon DynamoDB, Android NDK, Android, AWS Lambda...
Duolingo
Android, Kotlin, Slack, GitHub, DoubleClick for Publishers, Google Ads API...
Experience
- Scalability - 15 years
- Large-scale Projects - 15 years
- Android - 10 years
- Google Play Store - 10 years
- Kotlin - 8 years
- Firebase - 6 years
- Java - 5 years
- Jetpack Compose - 2 years
Preferred Environment
Git, Linux, MacOS, Large-scale Projects, Scalability, Social Networks, Android, Kotlin
The most amazing...
...project I've worked on could predict stock market variations by applying machine learning to tweet sentiments while ingesting all tweets in real-time.
Work Experience
Senior II Android Developer
2022 - PRESENT
Jobandtalent
- Built from scratch and published the Android business app of J&T in four countries with a team of six Android engineers.
- Developed the company's app BFF (back end for front end) with Spring Boot and introduced the company's first production-ready Kotlin service.
- Built an app using Jetpack compose and a multi-module application with navigation. Introduced SSE (server-sent events) prototype for real-time data visualization using Kotlin flow and coroutines.
Technologies: Android, Kotlin, Jetpack Compose, Spring Boot, Kubernetes, Android Studio, Firebase, Google Play Store, Jira, Microservices, OkHttp, REST, Robolectric, Espresso, MacOS, GitHub Actions, Model View ViewModel (MVVM)
Principal Engineer
2019 - 2022
Fleksy
- Converted a legacy mobile application into a fully customizable SDK that could be integrated into any third-party app.
- Led and mentored the Android team in migrating from Java to Kotlin while introducing the best software engineering practices.
- Built a large-scale licensing and installation tracking of third-party customers using Amazon DynamoDB and AWS Lambda, with automatic reporting and limit enforcement.
Technologies: C++, SDKs, Amazon DynamoDB, Android NDK, Android, AWS Lambda, Large-scale Projects, Scalability, Agile, Node.js, Dagger, Android SDK, B2C, Android Studio, Firebase, Google Play Store, Jira, Microservices, REST, Fresco, Espresso, MacOS, Model View Intent (MVI)
Android Developer
2019 - 2019
Duolingo
- Rebuilt the activity grading of Duolingo to implement a new API and started to introduce Kotlin to migrate the legacy Java application.
- Built a new component to create voice-to-text and grade users using Google libraries.
- Built new Duolingo activities from scratch in Kotlin, including the "connect and match pieces" and the "read text" activity.
Technologies: Android, Kotlin, Slack, GitHub, DoubleClick for Publishers, Google Ads API, Large-scale Projects, Scalability, Business to Consumer (B2C), Social Networks, Agile, Android SDK, B2C, Android Studio, REST, MacOS
Senior Android Developer
2017 - 2018
Johnson & Johnson
- Led a team to build Android applications. Performed workshops to improve the quality of unit and functional testing.
- Built a mobile application using a modular architecture that was later migrated to Kotlin. Introduced unit testing and UI testing using Espresso.
- Refactored legacy components into modern and reusable Kotlin components.
Technologies: Dagger, RxJava, MVVC, Model View Presenter (MVP), Android SDK, Kotlin, Java, Jetpack Compose, REST APIs, Google Play Store, RxJava 2, Dagger 2, Agile, JUnit, Retrofit, Large-scale Projects, Scalability, Business to Consumer (B2C), B2C, Android Studio, Jira, OkHttp, REST, Robolectric, Espresso, MacOS
Lead Android Developer
2017 - 2017
The Secret Company
- Built a prototype ride sharing application with real-time passenger and driver updates using Firebase.
- Led the mobile team and coordinated the back-end workflows for a real-time ride sharing application.
- Added voice command support with Google AI speech recognition services.
- Implemented dynamic route generation and visualization with Google Maps and Mapbox.
Technologies: CircleCI, Firebase, Mapbox, Google Maps, Dagger, RxJava, Mockito, Model View Presenter (MVP), Android SDK, Java, REST APIs, Google Play Store, RxJava 2, Dagger 2, Agile, JUnit, Retrofit, Kotlin, Large-scale Projects, Scalability, Business to Consumer (B2C), Social Networks, Node.js, B2C, Android Studio, Microservices, OkHttp, REST, Fresco, Espresso, Google Cloud Engine, MacOS
Senior Android Engineer
2012 - 2017
SoundCloud, Ltd.
- Created the play queue feature with live blurring on Android.
- Created the visual waveform characteristics of SoundCloud on Android.
- Created the introduction of the play history and recently played feature and coordinated it with the back-end on Android.
- Integrated AppBoy into the application for segmented notifications on Android.
- Rebuilt the SoundCloud audio recorder on Android.
- Integrated Chromecast on Android.
- Implemented Facebook and Google+ authentication systems.
- Developed internal mail notifications and a newsletter delivery system.
- Engineered social fanout of user activity to Facebook and Google.
- Integrated Twitter API partners with SoundCloud.
Technologies: Media Players, Chromecast, JUnit, GCM, Firebase, OkHttp, Dagger, RxJava, Java, Android, REST APIs, Linux, Google Play Store, RxJava 2, RESTful Services, Dagger 2, Agile, Retrofit, Kotlin, Large-scale Projects, Scalability, Business to Consumer (B2C), Social Networks, Node.js, Android SDK, B2C, Android Studio, Microservices, Jenkins, Scala, REST, Functional Reactive Programming, Music Streaming, Robotium, Robolectric, Espresso, MacOS
Senior Developer
2011 - 2012
Forward Internet Group
- Created MapReduce jobs in Hadoop to parse and analyze data.
- Created a chat application with live metadata anlayzer using DBpedia and web sockets in Node.js.
- Worked on a live Twitter stream sentiment analyzer to predict stock market using R, Node.js, and Hive.
- Created a keyword generator and subject analyzer using DBpedia, Node.js, and MongoDB.
Technologies: WebSockets, ZeroMQ, Apache Hive, Hadoop, Ruby on Rails (RoR), Ruby, REST APIs, Linux, RESTful Services, Agile, JavaScript, Large-scale Projects, Scalability, Business to Consumer (B2C), Node.js, Microservices, NoSQL, REST, MacOS
Senior Ruby Developer
2008 - 2010
Xing AG
- Shipped the company profiles project using Gearman for company profile automatic generation and management.
- Led the team on the events project responsible for creating and managing events and sending emails to event participants.
Technologies: Gearman, MySQL, Ruby on Rails (RoR), Ruby, REST APIs, Linux, RESTful Services, Agile, JavaScript, Large-scale Projects, Scalability, Business to Consumer (B2C), Social Networks, B2C, NoSQL, REST, MacOS
CTO
2007 - 2008
Project Amuso
- Defined the technical strategy and plan for our core products.
- Built an engineering team and established best development practices.
- Built and deployed our server infrastructure and database clusters.
- Built an MVC framework with decoupled front-end and back-end through an internal API layer.
Technologies: DevOps, Amazon S3 (AWS S3), MySQL, PHP, Linux, RESTful Services, JavaScript, Large-scale Projects, Scalability, Business to Consumer (B2C), B2C, Networks, MacOS
Tech Lead
2005 - 2008
DotMobile, Ltd.
- Created the Vodafone gateway interconector using VSS2.
- Developed the user management and bill PDF reporting in PHP.
- Built the Datacash gateway to emit payments from our SAP billing system.
- Created SMS usage alerts in real-time using mBlox.
- Built a customer CRM with lead management.
- Led a team of four engineers and designers.
Technologies: Software as a Service (SaaS), DataCash, Java, PHP, REST APIs, Linux, RESTful Services, JavaScript, Business to Consumer (B2C), B2C, Networks
Founder and CTO
2002 - 2007
Funtropy, S.L.
- Built six Java games for Nokia S40 and Samsung series.
- Built the first version of the Festuc.com social network project in PHP.
Technologies: Java ME, PostgreSQL, PHP, Linux, JavaScript, Business to Consumer (B2C), Social Networks, B2C, Networks
Founder and CTO
2000 - 2007
Galenicom, S.L.
- Created www.galenicom.com, a medical site with live search on Medline/PubMed with a website scraper/indexer.
- Created www.pricenoia.com, an Amazon price comparison site in real time with price scraping and indexing. In 2010, the site was rewritten in Node.ks with full text indexing in a five-node Elasticsearch cluster and distributed price indexing up to 1.5 million price checks per hour across six Amazon stores.
- Created www.econozco.com, a professional social network for Spanish users. The company was sold to Xing AG in 2007.
Technologies: Elasticsearch, RSS Feeds, Scraping, PostgreSQL, Amazon EC2, C++, PHP, Linux, JavaScript, Business to Consumer (B2C), Social Networks, B2C, C, Networks
Security Consultant
2001 - 2005
S21Sec S.A.
- Handled specialist tasks in the intrusion team responsible for finding vulnerabilities in banks, government institutions, and large companies.
- Analyzed and reviewed critical application source code of banks for security vulnerabilities and risks.
- Analyzed network topologies and DMZ vulnerabilities.
Technologies: Firewalls, C, Bash, Java, Cisco, Solaris, Linux, Networks
Experience
SoundCloud Android App
https://play.google.com/store/apps/details?id=com.soundcloud.androidThe SoundCloud music and audio app.
Duolingo Android App
http://www.duolingo.comThe well-known app to learn languages.
• Migrated some of the code from Java to Kotlin.
• Added new activities to the app, including the piece match and speak text activities.
• Implemented voice recognition using Google services.
• Migrated some of the code from Java to Kotlin.
• Added new activities to the app, including the piece match and speak text activities.
• Implemented voice recognition using Google services.
Skills
Libraries/APIs
RxJava 2, REST APIs, Fresco, Retrofit, Node.js, GCM, RxJava, ZeroMQ, Google Maps, Google Ads API
Tools
Git, Android Studio, Jira, CircleCI, Jenkins, Android NDK, Slack, GitHub
Languages
Kotlin, JavaScript, Java, Ruby, Bash, C++, C, Scala, PHP
Frameworks
Dagger, Android SDK, JUnit, Mockito, Ruby on Rails (RoR), Dagger 2, Unity3D, Unity, Unity2D, Media Players, Hadoop, Gearman, Espresso, Robotium, Robolectric, Spring Boot
Paradigms
B2C, REST, Agile, Functional Reactive Programming, Model View ViewModel (MVVM), Model View Intent (MVI), DevOps, Model View Presenter (MVP), Microservices
Platforms
Android, Firebase, Music Streaming, Linux, MacOS, Java ME, Solaris, Mapbox, Amazon EC2, Google Cloud Engine, AWS Lambda, Kubernetes
Storage
SQLite, Apache Hive, PostgreSQL, Amazon S3 (AWS S3), Elasticsearch, MySQL, NoSQL, Amazon DynamoDB
Other
Jetpack Compose, Large-scale Projects, Scalability, Business to Consumer (B2C), Social Networks, RESTful Services, Networks, OkHttp, Chromecast, Google Play Store, GitHub Actions, Cisco, Firewalls, Scraping, RSS Feeds, DataCash, Software as a Service (SaaS), MVVC, WebSockets, Game Design, SDKs, DoubleClick for Publishers
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