Valentine O.

Fullstack Java Developer

Avatar placeholder
Knutsford, United Kingdom

Experience

Nov 2024 - Present
1 year 2 months
Knutsford, United Kingdom

Fullstack Java Developer

Barclays

  • Delivered a low latency, high throughput Java based application trigger to TADS specifications, ensuring alignment with Oracle OWS-based Financial Crime Screening platform best practices.

  • Implemented and deployed innovative concurrency & parallel processing models using Java, Groovy, Bash Shell and PL/SQL to enhance screening workflows and sanctions alert processing.

  • Engineered automation scripts in UNIX (IBM AIX, Red Hat Linux) to eliminate repetitive operational tasks and improve efficiency across multiple FinCrime alerting states.

  • Consumed and transformed data from diverse sources, integrating outputs into downstream applications and updating upstream systems for screening accuracy.

  • Implemented complex SQL queries, stored procedures, and performance tuning strategies to optimize large-scale Oracle database operations.

  • Delivered defect-free solutions in live environments through proactive root cause analysis and knowledge base creation.

  • Collaborated with Financial Crime Technology stakeholders, 1st and 2nd Line of Defence, and solution architects to manage delivery expectations, risks, and dependencies.

  • Conducted proof-of-concept projects to evaluate and integrate emerging technologies, including API-driven microservices, in alignment with Barclays’ innovation strategy.

  • Developed RESTful web services for low latency real-time screening integrations leveraging Apache Tomcat and secure messaging protocols (JMS/MQ).

  • Produced technical documentation, low-level designs, and status reports to support compliance, audit, service management, change delivery, and internal governance requirements.

  • Successfully implemented real-time screening service integration with downstream risk systems, enabling faster detection of high-risk transactions.

  • Innovated functionality by incorporating real-time API calls into the screening engine leveraging Groovy scripts, achieving real-time sanctions block/unblock functionality.

Mar 2021 - Aug 2024
3 years 6 months
Birmingham, United Kingdom

Fullstack Java Developer

Rubies Technologies

  • Developed and implemented a high-throughput core banking application service for ledger operations, accounting, transaction management, customer management, journal management, card processing, collections, card management, and payment gateways with embedded risk controls.
  • Implemented the service tier of the digital banking platform using AWS serverless architecture with Java and Spring Boot to ensure scalability, security, high availability, and regulatory compliance.
  • Integrated 3rd party retail payment networks using microservices architecture with Spring Boot, Kafka, and AWS infrastructure.
  • Developed and implemented an ISO-8583 processing gateway using the JPOS Java library 2.1 and Spring Boot for host-to-host interface with the PostBridge interchange, including fraud detection features.
  • Implemented proactive monitoring using Elasticsearch, Logstash, and Kibana (ELK stack) for real-time logging and analysis of backend microservices.
  • Implemented a distributed caching solution with Redis, reducing average latency to 0.5 seconds for high-throughput operations.
  • Developed web-based back-office portals using React, Bootstrap, and Tailwind for customer profiling, transaction management, reporting, performance management, and dispute resolution, deployed as SPAs on AWS S3.
  • Integrated Cypress for end-to-end testing of user flows, component interactions, and API integrations.
  • Led and participated in transformation initiatives, migrating legacy systems to modern, resilient architectures with structured change management to ensure continuity and risk mitigation.
Jan 2021 - Aug 2023
2 years 8 months

Full Stack Java Developer

NUBEERO Limited

  • Architected and developed a high-performance, high-throughput, low-latency microservices-based insurance broker service using Spring Boot, Hibernate, Maven, Azure VM, Docker, and Kubernetes, achieving 99% success rate under peak load.
  • Utilized Azure Container Registry and Azure Kubernetes Service for microservices deployment and container orchestration.
  • Developed predictive models for customer behavior analysis with Python, Pandas, and NumPy to optimize underwriting processes and support data-driven decision-making.
  • Improved performance by optimizing SQL execution plans for high-volume data retrieval, enhancing data throughput by 60%.
  • Implemented logging and observability with Azure Monitor and the ELK stack for proactive monitoring and alerting.
  • Practiced test-driven development with JUnit, Mockito, and Spring Testing, resulting in a 45% decrease in production bugs.
Jul 2017 - Jan 2024
6 years 7 months
Lagos, Nigeria

Full Stack Java Developer, Solutions Architect

QUCOON Limited

  • Architected and implemented a low-latency, serverless, omni-channel digital banking financial service using Java 17 on AWS Lambda and AWS SDKs for web, mobile, and USSD channels, improving response times by 50% and reducing compute costs by 80%.
  • Developed a payment and switching management system based on the ISO 8583 framework with ISO packagers, source nodes, sink nodes, QMUX, ISO Server, and Transaction Manager, ensuring secure and reliable processing.
  • Utilized automated testing practices with JUnit & Mockito for unit and integration tests and contract testing using Pact, leading to a 45% reduction in production bugs.
  • Leveraged AI and machine learning algorithms for fraud detection and customer segmentation, enhancing transaction monitoring and risk management.
  • Led the transformation of legacy banking systems to a modern serverless architecture using AWS services with organizational change management and continuous risk controls.
May 2013 - Jun 2017
4 years 2 months

Software Developer, Data Analyst

ECOBANK Limited

  • Developed an ISO 8583 transaction processing payment gateway using the JPOS library to ensure high throughput communication between middleware services and Postilion FEP systems for MasterCard and VISA foreign currency transactions.
  • Implemented middleware automation scripts to digitalize e-commerce, card payments, and regulatory reporting business functions.
  • Automated retrieval of payments reconciliation data from 3rd party payment platforms (MasterCard, Visa, Postilion) for operational and dispute management processes.

Summary

A highly skilled Java full-stack engineer with expertise in developing and delivering high-quality, scalable, and maintainable software solutions using frameworks like Spring Boot, typescript and React for fullstack Development. Proficient in utilizing industry-aligned programming languages, frameworks, and tools to optimize performance and ensure seamless integration with business objectives. Adept at cross-functional collaboration with product managers, designers, and engineering teams to define software requirements and devise effective solution strategies. Committed to promoting code quality through adoption of test-driven development, contract testing, code reviews and adherence to secure coding practices.

Skills

  • Java Se
  • Java 8
  • Java 11
  • Java 17
  • Java 21
  • Python3
  • Javascript
  • Typescript
  • Jquery
  • Sql
  • Plsql
  • Html5
  • Css3
  • Springboot
  • Gradle
  • Maven
  • React
  • Bootstrap
  • Tailwind
  • Spring Cloud
  • Graphql
  • Jpos
  • Maven
  • Gradle
  • Git
  • Azure Devops
  • Pip
  • Anaconda
  • Graphql
  • Aws
  • Aws Serverless
  • Api Gateway
  • Aws Rds
  • Aws Ec2
  • Aws Eks
  • Aws Ecs
  • Aws Fargate
  • Azure Server Functions
  • Ubuntu Linux
  • Amazon Linux
  • Aws Amplify
  • Google Cloud Run
  • Google Cloud Functions
  • Kubernetes
  • Docker
  • Aws Eks
  • Aws Ecs
  • Fargate
  • Openshift
  • Gke
  • Chef
  • Microsoft Sql Server
  • Mysql
  • Postgresql
  • Mongo-db
  • Sqlite
  • Rabbitmq
  • Kafka
  • Aws Sqs
  • Junit
  • Mockito
  • Unittest
  • Jest
  • Cucumber
  • Microservices Architecture
  • Event Driven Architecture
  • Serverless Architecture
  • Rest Architecture
  • Solid
  • Azure Ci/cd Pipelines
  • Prometheus
  • Sentry
  • Netdata
  • Kibana
  • Grafana
  • Terraform
  • Gitlab

Languages

English
Advanced

Education

University of Lagos

Bachelor of Science, Computer Engineering · Computer Engineering · Lagos, Nigeria

Certifications & licenses

AWS Certified, Cloud Architect

AWS

NASBA CPE Certificate in Artificial Intelligence Essentials

Need a freelancer? Find your match in seconds.
Try FRATCH GPT
More actions

Similar Freelancers

Discover other experts with similar qualifications and experience

Rainer D.
Rainer D.

Enterprise Architecture Management / Software Developer Backend

View Profile
Khaja M.
Khaja M.

Technical Solutions Consultant

View Profile
Kazim R.
Kazim R.

Principal Security Architect - Contract Hands on

View Profile
Rainer L.
Rainer L.

Senior IT Consultant, Senior Software Architect, Senior Software Developer, Senior DevOps Engineer

View Profile
Hüseyin K.
Hüseyin K.

Senior Full-Stack Engineer

View Profile
Selvaraj K.
Selvaraj K.

Senior Full Stack & Cloud Architect

View Profile
Werner K.
Werner K.

Test Coordinator, Designer and Engineer

View Profile
Robert R.
Robert R.

Software Developer

View Profile
Christoph W.
Christoph W.

System Architect / System Engineer / Programmer

View Profile
Patrick W.
Patrick W.

AI Software Engineer

View Profile
Thomas J.
Thomas J.

Backend Developer, DevOps Engineer

View Profile
Achille C.
Achille C.

Backend/Frontend Developer

View Profile
Antoine L.
Antoine L.

Middleware, GCP Cloud and DevOps Engineer

View Profile
Satya V.
Satya V.

Lead Developer

View Profile
Niko S.
Niko S.

Developing Architect, Technical Lead "gridlytics"

View Profile
Rüdiger S.
Rüdiger S.

Full-Stack Software Engineer / Consultant for Digitalization

View Profile
Prasad T.
Prasad T.

Solution Architect / Senior Manager – DTC E-Commerce Platform

View Profile
Christoph B.
Christoph B.

Architect, Business Analyst, Developer

View Profile
Ulrich C.
Ulrich C.

Java Architect/Developer – Freelancer

View Profile
Alexander K.
Alexander K.

Senior Fullstack Developer

View Profile
Shamaila M.
Shamaila M.

Senior Software Architect

View Profile
Thorsten M.
Thorsten M.

Senior Test Engineer for an OpenShift Data and Analytics Platform

View Profile
Oliver B.
Oliver B.

Senior Software Architect

View Profile
Kiriakos K.
Kiriakos K.

Tech Lead: API Experience Platform

View Profile
Marcel M.
Marcel M.

Cloud-Architect, Senior Solution Architect, Senior Software-Engineer

View Profile
Stephan R.
Stephan R.

ICT Architect/Programmer, DevOps, Design, Implementation, Test, Documentation

View Profile
Daniel A.
Daniel A.

Enterprise Solutions Technical Architect

View Profile
Michal B.
Michal B.

Senior Golang Engineer

View Profile
Jens R.
Jens R.

Technical Product Owner

View Profile
Michael F.
Michael F.

Freelancer, Solution Architect

View Profile