Horaci is available for hire

Horaci Cuevas

Verified Expert in Engineering

Large-scale Projects Developer

Barcelona, Spain

Toptal member since May 5, 2017

Expertise

Git Android Kotlin Firebase Chromecast Development Linux REST API Agile Development Node.js Ruby on Rails JavaScript Java

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

Availability

Part-time

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.android

The SoundCloud music and audio app.

Duolingo Android App

http://www.duolingo.com

The 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.

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

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring