Christopher is available for hire

Christopher Brown

Verified Expert in Engineering

Back-end Developer

Location

London, United Kingdom

Toptal Member Since

December 27, 2021

Christopher is a back-end software engineer with a bachelor's degree in computer science from Queen's University Belfast. He has worked on high throughput, latency-sensitive systems—implementing features used by millions of people at companies like Vonage, Blockchain.com, and CME. Christopher has 7+ years of extensive engineering experience using Java, Kotlin, Python, Kafka, Docker, PostgreSQL, and more.

Back-end Java Software Engineering Cryptocurrency Java 8 Git Linux SQL Spring Apache Kafka MySQL REST APIs Kotlin Spring Boot Selenium Filebeat

Portfolio

10x Banking

Kotlin, Amazon S3 (AWS S3), Amazon Athena, Apache Kafka, Kafka Connect

Vonage

Java, Apache Kafka, Filebeat, Python, Docker, Nomad, MySQL, Architecture...

Blockchain.com

Kotlin, Java, Nomad, PostgreSQL, Docker, Protobuf, Apache Kafka, Cryptocurrency...

Experience

Software Engineering - 5 years Java - 5 years Linux - 4 years Cryptocurrency - 3 years Apache Kafka - 3 years Python - 2 years Kotlin - 2 years Amazon Web Services (AWS) - 1 year

Availability

Part-time

Preferred Environment

IntelliJ IDEA, MacOS, Linux, Java, Kotlin

The most amazing...

...feature I've implemented was a cryptocurrency airdrop gifting over 15 million dollars worth of tokens to 300,000 people worldwide, subject to KYC criteria.

Work Experience

Software Engineer

2022 - 2023

10x Banking

Developed an SQL query API data lake access gateway, facilitating interface compatibility with Amazon Athena, Apache Pinot, and Aurora using Kotlin, which streamlined data queries and improved accessibility for analytics and reporting.
Created a bulk operations application employing reactive Java with Spring Boot, enhancing the efficiency and scalability of data processing tasks within the organization.
Made significant contributions to the data lake infrastructure, including integrations with Kafka Connect, Amazon S3, Amazon Athena, Apache Airflow, and Aurora, strengthening the organization's data processing and management capabilities.
Focused heavily on PostgreSQL performance optimization, implementing strategies that significantly improved database efficiency and query speeds, enhancing overall system performance.

Technologies: Kotlin, Amazon S3 (AWS S3), Amazon Athena, Apache Kafka, Kafka Connect

Java Engineer

2020 - 2021

Vonage

Played a key role in meeting tight deadlines, including a two-week delivery timeline for new integrations into production environments.
Designed and implemented networking APIs in accordance with the Camara specifications under the Linux Foundation, enhancing the company's offerings in telecommunications networking solutions.
Integrated the Camara API for SIM swap and number verification across multiple communications service providers (CSPs), streamlining operations and improving customer service efficiency.
Integrated a Gradle catalog with automatic version bumping for centralized dependency management, improving project build times and reducing issues related to outdated libraries and critical vulnerabilities across the company.
Led the redesign and delivery of a project to migrate the SMS data pipeline, handling 2+ billion messages daily, to Kafka using Filebeat. This initiative modernized the infrastructure and ensured zero data inconsistencies post-migration.
Fixed an overflow bug in Apache Filebeat that was discovered during the SMS data pipeline migration project. The contribution was accepted and merged into the open-source project, enhancing its reliability for users worldwide.

Technologies: Java, Apache Kafka, Filebeat, Python, Docker, Nomad, MySQL, Architecture, Microservices, Spring Boot, REST APIs, Jenkins, Software Development, Spring, Git, SQL, Back-end, Dashboards, API Integration, Automated Testing, REST Assured, Selenium, Kotlin, Kubernetes

Platform Engineer

2019 - 2020

Blockchain.com

Contributed to a leading consumer crypto platform, specializing in crypto exchange services, by inheriting and enhancing the Mercury events service, achieving one hundred times improvement in read and write performance.
Utilized a robust tech stack including PostgreSQL, Kafka, Kotlin, and Java to deliver high-performance features end-to-end, crossing over into other services such as real-time candles, airdrop center, and order history CSV.
Delivered the Block Stack airdrop, distributing $70 million worth of crypto tokens to verified customers, showcasing an exceptional ability to execute large-scale financial transactions securely and efficiently.
Increased the write and read performance of the crypto exchange event service by over one hundred times, significantly improving the system's efficiency and user satisfaction by enabling faster transaction processing.
Implemented an order history feature in CSV format for the crypto exchange, providing users with a comprehensive and downloadable transaction history, enhancing transparency and trust in the platform.
Executed a massive crypto airdrop, successfully registering 300,000 individuals to receive verified cryptocurrency directly into their wallets, demonstrating effective project management and execution capabilities.
Added real-time candlestick charts to the crypto exchange's price charts, improving the trading experience by providing users with dynamic and detailed market analysis tools.

Technologies: Kotlin, Java, Nomad, PostgreSQL, Docker, Protobuf, Apache Kafka, Cryptocurrency, Amazon Web Services (AWS), IntelliJ IDEA, Linux, Microservices Architecture, REST APIs, Software Development, Git, Back-end, Dashboards, API Integration

Software Engineer

2018 - 2019

Bosonic (formerly OTCXN)

Contributed significantly to the development of OTC and exchange trading platforms, utilizing TIBCO, FIXML, and Java to enhance trading efficiency and reliability.
Developed and maintained an automated test suite, enabling concurrent test runs across multiple FIX gateway sessions to ensure platform integrity and performance.
Innovated a "Robo-trader" solution to automate order placement in test environments, providing realistic trading conditions for testing and client demonstrations.
Designed a multithreaded integration test framework that supports WebSocket, FIX connections, and REST interfaces, streamlining the testing process for various trading platform functionalities.
Implemented a liquidity provision strategy through the Robo-trader, improving the representation of market conditions in our test environments and enhancing the demonstration experience for potential clients.
Played a pivotal role in team expansion and talent acquisition, interviewing and onboarding new engineers as the second hire in the Belfast office, contributing to the team's growth and development.

Technologies: Java, Apache Kafka, TIBCO, Software Development, Spring, Git, MySQL, Back-end, Dashboards, Selenium, API Integration, Web Scraping

Junior Software Engineer

2017 - 2019

CME Group

Designed and maintained comprehensive automated test suites, utilizing tools such as SOAP UI, REST Assured with behavior-driven development (BDD), and Selenium with BDD to test web services and graphical user interfaces thoroughly.
Developed a sophisticated Selenium WebDriver automation suite in Java, specifically for GUI integration tests, facilitating effective user interaction testing, including clicking and dragging components.
Created a REST Assured integration test suite for REST endpoints in Java, ensuring the robustness and reliability of web service interactions within the STP application.
Built a FIXML integration test suite using Cucumber and Java, enhancing the application's compatibility and integration capabilities with financial information exchange protocols.
Innovated in GUI testing by employing Selenium and BDD methodologies to automate complex user interaction scenarios, significantly reducing manual testing efforts and improving test accuracy.

Technologies: Java, Software Development, Spring, Git, MySQL, Back-end, Selenium

Skills

Languages

Java, Kotlin, Java 8, SQL, Python, C#, C++

Other

Back-end, Software Engineering, Cryptocurrency, API Integration, Dashboards, Filebeat, TIBCO, Nomad, Architecture, Software Development, Trading, Web Scraping, Kafka Connect

Frameworks

Spring Boot, Spring, Selenium, Unity

Libraries/APIs

REST APIs, ReactiveX, Protobuf

Tools

IntelliJ IDEA, Git, Jenkins, REST Assured, Amazon Athena

Platforms

Linux, Apache Kafka, MacOS, Amazon Web Services (AWS), Docker, Android, Kubernetes

Storage

MySQL, PostgreSQL, Amazon S3 (AWS S3)

Paradigms

Microservices Architecture, Microservices, Unit Testing, Automated Testing

Education

2014 - 2018

Bachelor's Degree in Computer Science

Queen's University Belfast - Belfast, Northern Ireland, UK

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