Luciano Greiner dos Santos, Developer in Porto Alegre - State of Rio Grande do Sul, Brazil
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Luciano Greiner dos Santos

Verified Expert  in Engineering

Full-stack Developer

Porto Alegre - State of Rio Grande do Sul, Brazil
Toptal Member Since
June 9, 2016

Luciano is a seasoned professional with a decade and a half of experience developing Java enterprise applications. Currently, he's focused on big-data technologies such as Spark, Cassandra, Kafka, and Elasticsearch. He's capable of working as a full-stack engineer, having also worked with JavaScript and AngularJS in the past. Luciano is also fluent in English, has a native level in Portuguese, and has basic Spanish speaking abilities.


Web3.js, Ethers.js, Ethereum, Solidity, Rust, TypeScript...
Creator Networks Inc.
Non-fungible Tokens (NFT), Solidity, Full-stack
OffStage Holdings
Web3.js, Solidity, Blockchain, GraphQL, Figma, React, Kubernetes




Preferred Environment

Visual Studio Code (VS Code), Git, IDEA IDE

The most amazing...

...thing I've done was extract 100,000 of the most popular people and what their professions are from one year of raw Twitter data.

Work Experience

Lead Blockchain Engineer

2022 - PRESENT
  • Served as a lead engineer and manager of NFT projects for remarkable clients in the entertainment, hospitality, and restaurant industries.
  • Architected and developed an automated platform to customize and deploy standardized smart contracts.
  • Developed several Web3.js components to interact with smart contracts and back-end services.
  • Built advanced blockchain monitoring and analytics tools to keep on-chain data in sync with high-performance cache stores.
Technologies: Web3.js, Ethers.js, Ethereum, Solidity, Rust, TypeScript, Amazon Web Services (AWS), IPFS, GraphQL, Full-stack, React, Kubernetes

Blockchain Consultant

2022 - 2022
Creator Networks Inc.
  • Provided training and lectures about NFT development standards and good practices.
  • Trained and lectured about blockchain subgraph development.
  • Advised a project to empower YouTube content creators to sell and share revenue from their channels though NFTs.
Technologies: Non-fungible Tokens (NFT), Solidity, Full-stack

Lead Web3.js and Blockchain Engineer

2022 - 2022
OffStage Holdings
  • Developed an Ethereum smart contract in Solidity using the ERC721 standard for an NFT collection.
  • Built a Web3.js front end to mint and collect payments for NFTs, show user assets, and process utility orders.
  • Deployed a scalable and secure Web3 infrastructure using OpenZeppelin Defender and AWS.
Technologies: Web3.js, Solidity, Blockchain, GraphQL, Figma, React, Kubernetes

Director of Engineering (Blockchain)

2020 - 2022
  • Planned and put together an engineering team for a disrupting blockchain-based social media platform that will reward regular users with crypto and mint NFTs for every post created to give back true content ownership.
  • Defined and implemented software architecture and blockchain technologies.
  • Managed the development of a new smart contract for a social media token.
  • Participated in developing Web3.js components to let users sign in to our DApp. This enabled them to check their token allocations, use other functions like username reservation, and participate in special promotions.
  • Collaborated on developing an NFT collection and a smart raffle contract using chainlink technology, which we made accessible through Web3.js.
  • Managed a globally distributed team of over 25 engineers and was in charge of requirements specification; constantly communicated with the executive board to translate high-level business requirements into software deliverables.
Technologies: Java, Blockchain, Management, Web3.js, Cassandra, Apache Kafka, Spring, Non-fungible Tokens (NFT), Solidity, GraphQL, Full-stack, Figma, React, Kubernetes

Python Engineer

2021 - 2021
  • Developed new data visualizations for field irrigation information.
  • Pioneered new reports for nitrogen application recommendations.
  • Helped fix a dozen bug fixes and worked on improvements on partner integrations, such as John Deere.
Technologies: Python, JavaScript, Full-stack

Lead Java Engineer

2020 - 2021
  • Developed an engine for applying processing rules to telemetry data collected from tractors and other appliances.
  • Implemented over 30 different rules to detect failures on tractors.
  • Implemented an analytics engine that retrieves historical telemetry data to detect abnormal tractor behaviors, like undesired location changes or awkward odometer movements.
Technologies: Java, Spring, Amazon Web Services (AWS), Amazon DynamoDB, Full-stack

Senior ES Consultant

2019 - 2020
MediaMinds, LLC
  • Worked on the performance tuning of the Elasticsearch cluster set up.
  • Refactored the existing Elasticsearch queries and improved the overall response time from over 30s to a mere sub-second.
  • Developed a new SMS campaign statistics dashboard using advanced Elasticsearch and Kibana query capabilities.
Technologies: Elasticsearch, Angular, PHP, Full-stack, Data Analytics

Lead Full-stack Engineer

2017 - 2019
  • Played a leadership role in a global development team.
  • Implemented several new features to a charitable raffle system.
  • Completely refactored the front end and made the app more attractive to clients.
  • Implemented an autoplay function which enhanced sales by 10%.
  • Provided support to sporting clubs for the raffle system.
Technologies: Sass, Angular, Java, Groovy, AWS Lambda, AWS CloudFormation, Full-stack

Full-stack Engineer

2017 - 2019
  • Developed new features and maintained a SaaS enterprise map application.
  • Created a new admin dashboard to manage billing and customer support.
  • Implemented a new custom route functionality on the map system.
  • Integrated a unit testing framework to improve general delivery quality.
Technologies: GIS, PostgreSQL, jQuery, JavaScript, Jakarta Server Pages (JSP), Java, Full-stack

Full-stack Engineer

2016 - 2019
  • Developed a crawler module to load social video media content from Vimeo.
  • Created enhancements to media crawlers to increase coverage of Twitter, YouTube, and Instagram data feeds.
  • Developed a new customer subscription and payment platform integrated with Stripe.
  • Migrated a legacy servlet-based infrastructure to Jax-RS using Jersey.
  • Created an Elasticsearch REST plugin to add a result counting HTTP header into server responses.
  • Integrated Spark SQL and Elasticsearch to enable custom data research.
Technologies: Scala, Kibana, ActiveMQ, Cassandra, Elasticsearch, Java, Full-stack, Data Analytics

Chief Java Architect

2016 - 2018
Aurea Software
  • Designed a common alert streaming infrastructure to use Kafka and Spark to be used across multiple company products.
  • Developed plugins to enable monitoring and troubleshooting of several applications used by important clients.
  • Created a custom report dashboard based on data collected by sensors streams.
Technologies: Scala, Big Data, REST, JAX-RS, Cassandra, Spark, Apache Kafka, Java, Full-stack

Senior JEE Architect

2015 - 2016
Powerlogic | RS Department of Justice
  • Designed and developed a standard RESTful service architecture using Java 8, Jax-RS, and CDI being used in several projects.
  • Developed a security system to deliver consolidated application access and user information from Active Directory and HR systems through a REST interface.
  • Mentored and trained development teams on AngularJS.
  • Developed and designed a standard component-based AngularJS reference architecture.
  • Maintained and updated Jenkins and Sonar installations for dozens of department projects.
  • Supported and provided assessments for development teams.
Technologies: JSON, RESTful Development, REST APIs, TypeScript, Gulp, Hazelcast, Spring, JSF, Oracle, WebLogic, Java EE, AngularJS, JavaScript, Java 8, Full-stack

Senior Consulting Architect

2014 - 2015
TOTVS | Brazil Ministry of Health
  • Developed a real-time module to enable the exchange of harm notifications data between cities, states, and central federal government spheres.
  • Created an installable version of the web application using an embedded JavaFX browser and IzPack so it could be used on standalone offline mode.
  • Supported an application deployment into a huge cluster infrastructure data center of the Ministry of Health.
  • Developed a new disease-harm notification instruments using Java, REST, and AngularJS.
Technologies: Spring, JSON, RESTful Development, REST APIs, JBoss, PostgreSQL, Oracle, AngularJS, Java EE, JavaScript, Java, Full-stack

IT Specialist

2008 - 2015
  • Developed a RESTful integration API using Spring REST, JDBC, and DB2 for ILC and ICLA legacy systems, enabling the creation of their mobile version with IBM Worklight Platform.
  • Implemented a batch data exchanger between our labor-claiming software with SAP, using Java NIO API and DB2.
  • Worked as a Java instructor representing IBM for the BTP internship program in a local college institution attended by around 100 students.
  • Developed a spreadsheet import and export function for the Intranet Labor Claiming software using Apache POI and Java.
  • Created an event-based SQL parser to enable batch editing of thousand of existing DB2 statements.
Technologies: JSON, RESTful Development, REST APIs, IBM Worklight, Spring, IBM Db2, WebSphere, Java EE, Java

Senior Consulting Architect

2014 - 2014
SRM Asset Management
  • Developed and designed a micro-services architecture using standalone Java agents and RabbitMQ for their financial system.
  • Created an integration layer between a SQL Server Message Broker and RabbitMQ to enable real-time processing of operations executed on the legacy system.
  • Developed a payments dispatcher web interface using AngularJS and WebSockets.
Technologies: JSON, RESTful Development, REST APIs, AngularJS, Microsoft SQL Server, GlassFish, Hazelcast, RabbitMQ, Microservices, Spring, Java EE, Java 8

Senior Consulting Architect

2012 - 2014
TOTVS | Brazil Ministry of Health
  • Designed and developed an AngularJS front-end architecture to enable rule-intensive harm notification forms.
  • Developed a dozen disease notification forms and business rules using Java, Spring, Oracle, and AngularJS.
  • Created alerts and reports for epidemic patterns based on real-time data from collected from harm notifications.
  • Designed a data exchanger to enable online and offline notifications.
  • Developed a harm notification mobile application using jQuery Mobile.
Technologies: Oracle RDBMS, PostgreSQL, Spring, JSON, REST APIs, RESTful Development, JBoss, AngularJS, Java EE, JavaScript, Java

Training Instructor

2006 - 2011
  • Taught as an instructor on JSP/ Servlets, Struts, Spring Framework, Enterprise JavaBeans, Hibernate, JavaServer Faces, and JBoss Seam.
  • Worked in more than 25 courses over five years.
  • Responsible for creating course handouts and presentation slides.
Technologies: Java

Senior Java Developer

2007 - 2008
  • Developed a port change and discharge schedules module using EJB, Hibernate, and Struts.
  • Created a data integration loader for Vessels Lloyds Feed service using Oracle PL/SQL and JDBC.
Technologies: Hibernate, WebSphere, Oracle, Apache Struts, Enterprise Java Beans (EJB), Java

Java Developer

2005 - 2007
Telefonica España
  • Developed a document workflow module using Java and PL/SQL.
  • Created an integration layer between the web application and the back-office telecom system.
Technologies: PL/SQL, Oracle, WebLogic, Spring, Apache Struts, Java


Artemis is a crawler that indexes social media content from multiple web sources into a more than 10 billion records Cassandra database and Elasticsearch index that serves enterprise customers and data analysis feeds.


CEJUSC is an AngularJS application used by the RS State Justice Department into pre-trial conflict mediation procedures helping to underload the justice system.

Security Services

Security Services is a restful application that serves consolidated user and application authorization data from Active Directory and other HR systems for dozen applications on RS State Justice Department.


SINAN is a web application used by hospitals and health units across the country to enable disease case notifications to the govern spheres. The collected information is used to detect public health risks, such as epidemics. The application was successfully proven to track a Dengue epidemic occurred in Brazil in early 2015.

ILC - Intranet Labor Claiming

ILC is the official application used by more than 400,000 IBM employees weekly to claim worked hours through using a standalone and mobile version.


New SRM is a financial management system used for credit analysis, CRM, and payment management developed using Microservices, AngularJS, and WebSockets.

ICLA - Intranet Contract Labor Approval

ICLA is a global application used by IBM to enable contract labor approval and payment; developed with Java and DB2.

LMS - Logistics Management System

LMS is a software developed for Bunge Global Agribusiness to manage port and vessel operations such as schedules, loading, and discharge.


Credenciadas is a web-based system to enable Telefonica Dealers online telecom core business service operations, such as line/phone sales and plan migrations.

SCJP - Sun Certified Java Programmer

I am a Sun Certified Java Programmer.

SCWCD - Sun Certified Web Components Developer

Sun Certified Web Components Developer

SCBCD - Sun Certified Business Components Developer

I am a Sun Certified Business Components Developer.

SCEA - Sun Certified Enterprise Architect

I am a Sun Certified Enterprise Architect (Step 2).

Functional Programming Utilities for Java 8
A personal open source library to add extra functional programming utilities into Java 8 code inspired by Scala.

Omni - Blockchain Social Media

Omni is a social media platform that aims to give back the ownership of the content to the hands of the users. They accomplished this by minting NFTs for every user-owned post created on the platform.

The platform would them distribute rewards for engagement in the form of tokens directly to the content NFTs. That means posts could also be traded along with their rights to receive royalties.

OverHyped Pandas
OverHyped Pandas is an NFT collection deployed on the Ethereum network with great artwork and utility.

The project was developed from the ground, including the smart contract and portal of a Web3.js front end to let users mint, pay, and manage their assets.
2000 - 2006

Bachelor's Degree in System Analysis

Unisinos - Universidade do Vale do Rio dos Sinos - São Leopoldo - Brazil


JDBC, JAX-WS, JAX-RS, Node.js, Moment.js, Spring REST, React, Web3.js, Stripe, Stripe API, REST APIs, jQuery


Eclipse IDE, Bitbucket, Subversion (SVN), Jetty, Git, Apache Tomcat, RabbitMQ, Apache Maven, IntelliJ IDEA, Bower, Apache Ant, AWS SDK, AWS CloudFormation, Gulp, ActiveMQ, SoapUI, Grunt, Amazon Simple Notification Service (Amazon SNS), Figma, IDEA IDE, Kibana, IBM Worklight, GIS, Apache Storm


JSF, Apache Spark, AngularJS, Spring, JPA, Bootstrap, Spring Boot, Hibernate, Spring JDBC, Spring MVC, Next.js, Hadoop, Angular, Angular Material, OAuth 2, Activiti BPM, Apache Struts, Spark, Jakarta Server Pages (JSP), JavaServer Faces


Java 8, Python, HTML5, HTML, SQL, JavaScript, Java, Solidity, GraphQL, Groovy, Perl, Scala, TypeScript, Sass, Python 3, PHP, CSS, Rust


Service-oriented Architecture (SOA), REST, Lambda Architecture, Microservices, RESTful Development, Management


Kubernetes, AWS Elastic Beanstalk, Docker, Amazon EC2, Amazon Web Services (AWS), Oracle, Linux, Blockchain, Ethereum, Apache Kafka, JBoss, WebSphere, AWS Lambda, Eclipse, Java EE, Visual Studio Code (VS Code), Jakarta EE


JSON, Elasticsearch, Cassandra, PostgreSQL, H2, Spring Data, Amazon S3 (AWS S3), Hazelcast, IBM Db2, Neo4j, MySQL, MongoDB, Microsoft SQL Server, Oracle RDBMS, PL/SQL, Amazon DynamoDB


Enterprise, JAAS, WebLogic, SOAP, EclipseLink, EJB 3, CDI, Enterprise Java Beans (EJB), Message Queues, Non-fungible Tokens (NFT), Full-stack, Data Analytics, Big Data, WebSockets, Unix Shell Scripting, OAuth, AWS Cloud Architecture, Lambda Functions, GlassFish, Ethers.js, IPFS

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