Wilber Torres Cristobal, Developer in Lima, Callao Region, Peru
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Wilber Torres Cristobal

Verified Expert  in Engineering

Algorithms Developer

Lima, Callao Region, Peru

Toptal member since November 10, 2017

Expertise
Back-end DevelopersCode ReviewDebuggingAlgorithmsAWSJavaPHPSpringMySQLWindows DevelopmentLinuxHibernateTypeScriptGit
Bio

Wilber is a senior Java developer and problem solver with experience bringing up distributed and scalable architectures as well as refactoring and optimizing existing ones. He has the ability to learn quickly and is always committed to delivering top-notch solutions. Wilber is always looking for challenges and staying up-to date on the industry's latest tech.

Portfolio

Amazon.com
Algorithms, Agile Software Development, APIs, Java, Jakarta Server Pages (JSP)...
Amazon
Spring, Java, MySQL, System Design, JavaScript, TypeScript, Spark...
Verizon
Spring Boot, Cloud Foundry, Jenkins, Java, System Design, Oracle PL/SQL...

Experience

  • Algorithms - 6 years
  • Java - 5 years
  • Spring - 5 years
  • Linux - 4 years
  • MySQL - 4 years
  • Distributed Systems - 3 years
  • Agile Software Development - 3 years
  • JavaScript - 2 years

Availability

Full-time

Preferred Environment

Linux

The most amazing...

...thing I've built is a web scraping tool using Breadth-first search algorithm to download MP3s from a music portal.

Work Experience

Senior Software Engineer

2022 - 2023
Amazon.com
  • Designed, implemented, and delivered the add-to-cart project to production, which adds a button to retail search results; it implies developing this feature with zero latency regression and zero issues in production.
  • Drove the ranking project on the back end of search results for retail search results; it implied syncing with five external teams and agreeing on my proposed proposal.
  • Participated in the Samurai Group reviewing technical design documents external to my team and reviewed 38 technical design documents where I contributed to raising concerns, gaps, or proposing alternatives.
Technologies: Algorithms, Agile Software Development, APIs, Java, Jakarta Server Pages (JSP), ETL, Architecture, Hadoop, Amazon Web Services (AWS), Back-end, API Development, Code Review, Debugging, REST, Databases, Spring, Distributed Systems, Low-latency Software, Sequenced Architecture, Apache Lucene, Apache Solr

Software Development Engineer

2018 - 2021
Amazon
  • Designed and implemented color swatches back end; it is an ETL service that processes 50B records on daily basics using Spark and AWS Glue jobs.
  • Reduced the latency on the pinch to zoom project by five milliseconds; Amazon Search has a zero latency regression policy. I worked on the research to reduce the latency for our feature pinch to zoom.
  • Worked on color swatches migration, the front end required to migrate the new API, which needs to touch the framework part on a service that handles 1 million transactions per second.
Technologies: Spring, Java, MySQL, System Design, JavaScript, TypeScript, Spark, Amazon DynamoDB, ETL, Back-end, Python, API Development, Code Review, Debugging, React, REST, Architecture, Databases, Algorithms, Distributed Systems, Low-latency Software, Sequenced Architecture, Apache Lucene, Apache Solr

Software Engineer

2015 - 2018
Verizon
  • Developed a REST API using Spring Boot and Swagger.
  • Designed, developed, and documented my frameworks and tools based on microservices such as config servers, caching, logging, or REST client.
  • Refactored and improved the performance in the bottlenecks (push notification time was reduced by 40% using caching and reducing calls to the back end).
  • Managed a Jenkins CI server using Docker and Spring Cloud.
  • Troubleshot production issues by reviewing the logs and managing deployments/rollback.
Technologies: Spring Boot, Cloud Foundry, Jenkins, Java, System Design, Oracle PL/SQL, Back-end, Python, API Development, Code Review, Debugging, REST, React, Architecture, Databases, Algorithms, Spring, Distributed Systems

Senior Software Engineer

2014 - 2015
EFACT SAC
  • Developed SOA services with unit testing using JAX-WS.
  • Created signed XML documents using Java Crypto API.
  • Engaged in client support and facilities to integrate their system with our API.
  • Refactored the invoice XML signature component to process more documents daily.
Technologies: Digital Signatures, XML, Service-oriented Architecture (SOA), Java, Back-end, Code Review, Debugging, REST, Architecture, Databases, Spring, Distributed Systems

Java Back-end Developer

2014 - 2014
COSAPI SOFT SAC
  • Designed and developed web services to integrate other back end consuming queues, web services, and EJB.
  • Wrote documentation and diagrams in an interface control document (ICD) for APIs.
  • Collaborated with the team for passing to production and troubleshooting.
  • Developed unit tests using Mockito for external resources.
Technologies: BPM, Enterprise Java Beans (EJB), Java Message Service (JMS), Oracle Service Bus (OSB), Service-oriented Architecture (SOA), Java, REST, Spring

Experience

Algorithm Problems

https://github.com/Ziklon/algorithms
This is a personal folder that contains solutions for the most famous online contests, such as TopCoder, Codeforces, CodeChef, UVA, and SPOJ.

There are many problems (around 1,000) in the folder related to different kinds of algorithms like dynamic programming, graphs, math, string hashing, and greedy algorithms.

Coach/Problem Setter on HuahCoding

HuahCoding is a community of programmers who want to improve their programming/algorithm skills. I hosted many contests, writing the problems and being the judge. I coached two teams in 2014 on the South America ACM/ICPC.

Jira Checkout Plugin

https://www.mumosystems.com/products/checkout
Checkout streamlines your purchasing requests, procurement, and asset management with the simplicity and power of Jira Service Management. Eliminate emails and phone calls by centralizing all of your requests, orders, and fulfillment in Checkout.

Education

2008 - 2013

Bachelor's Degree in Computer Engineering

Jose Faustino Sanchez Carrion - Huacho, Peru

Certifications

JANUARY 2023 - PRESENT

Advanced Learning Algorithms

Coursera

JANUARY 2023 - PRESENT

Supervised Machine Learning: Regression and Classification

Coursera

JUNE 2016 - PRESENT

Oracle Certified Associate, Java SE 7 Programmer Certification

Oracle

Skills

Libraries/APIs

API Development, jMock, Node.js, Google API, React, Apache Lucene, Java Message Service (JMS), Jira REST API

Tools

Eclipse IDE, Apache Maven, Git, Gradle, NPM, Apache Solr, Jenkins, IntelliJ IDEA, Jira

Languages

PHP, Java, TypeScript, C++, JavaScript, Python, XML, Java 7

Frameworks

Spring, Jakarta Server Pages (JSP), Angular, Spring Security, JSON Web Tokens (JWT), Hibernate, Spark, Spring Boot, Hadoop

Paradigms

REST, Design Patterns, Object-oriented Programming (OOP), Agile Software Development, ETL, Service-oriented Architecture (SOA)

Platforms

Amazon Web Services (AWS), Windows, MacOS, Linux, Oracle Database, Oracle

Storage

MySQL, Spring Data, MongoDB, Oracle PL/SQL, PostgreSQL, Amazon DynamoDB, Databases, JSON

Other

Algorithms, System Design, Back-end, Code Review, Debugging, Low-latency Software, Sequenced Architecture, Distributed Systems, Cloud Foundry, Digital Signatures, Oracle Service Bus (OSB), BPM, Enterprise Java Beans (EJB), APIs, Machine Learning, Operating Systems, Compilers, Architecture, Coaching, Mentorship

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