05/28/2025 updated

AM
100 % available

Senior Java Developer - Freelancer - Contractor

Ploiesti, Romania
Only remote
BSc Information Technology, MSc Business Engineering and Management
Ploiesti, Romania
Only remote
BSc Information Technology, MSc Business Engineering and Management

Profile attachments

CV - Andrei Mandris

Java (Programming Language)Spring SecurityAmazon Web ServicesArchitectureAtlassian JiraCloud ComputingDatabasesQuartz (Graphics Layer)Electronic Data Interchange (EDI)GradleJava Message Service (JMS)PostgreSQLApache MavenMongoDBOpenShiftOracle ApplicationsPrometheusSoftware SystemsGoogle CloudSnowflakeGrafanaSpring BootGitSpring DataKotlinKubernetesApache KafkaTeamcityRestful ApiTerraformDockerJenkinsMicroservices
I am a Senior Java / Kotlin Developer / Freelancer / Consultant with over 10 years of experience. I use my expertise to identify and implement clients' needs with regard to their software solutions.

About my skills:
• Java: Spring Boot 3, Spring Data, Spring Quartz, Spring Security
• Data exchange: Apache Kafka, Kafka Connect, JMS, RESTful web services
• Architecture: Microservices architecture, Hexagonal & Onion architectures
• Monitoring: Prometheus, Grafana, Alertmanager
• Cloud: AWS, Google Cloud Platform
• Databases: Postgresql, Mongo, Oracle, Snowflake
• Tools & others: Git, Maven, Gradle, Jira, TeamCity, Jenkins, Openshift, Docker, Kubernetes, Terraform

Only interested in remote work

Do you need software solutions for your business? Let's connect!

Skype: Andrei Mandris
Email: andrei.mandris.dev@gmail.com

Languages

EnglishNative speakerRomanianNative speaker

Project history

Senior Java Developer

Roche

Pharmaceuticals & Medical Technology

>10.000 team member

The client, a global pharmaceutical company, needed a robust reporting system to track clinical trial progress, but faced major challenges aggregating real-time patient and sample data from heterogeneous, siloed systems. 
  • Increased the visibility over 80% of the data by creating a dashboard service deployed in AWS which was aggregating the data from multiple sources and exposing statistics and reports about the uploaded medical files, collected samples, enrolled patients and study context information.
     
  • Reduced the lag of report building by 90% by designing a series of granular events for each change in the source systems and handled them asynchronously allowing the reports to refresh in real-time. 
 Skills: Java, Kotlin, AWS, Spring Boot, MongoDB, Snowflake, RabbitMQ, Kubernetes, Docker, Maven, GitLab

Senior Java Developer

Roche

Pharmaceuticals & Medical Technology

1000-5000 team member

The client, a global pharmaceutical company, was losing users because they were unable to offer them AWS based file ingestion services to integrate with. 
  • Increased the number of users by 50% by developing an AWS cloud based dropzone solution which was ingesting files through an S3 bucket and was processing the resulting S3 events coming in through an SQS messaging queue. 
 Skills: Java, Kotlin, AWS, Spring Boot, MongoDB, AWS SQS, AWS S3, Terraform, Kubernetes, Docker, Maven, GitLab, GCP 

Senior Java Developer

Delivery Hero

Transport & Logistics

>10.000 team member

The client, a global top player in the Q-commerce industry, was struggling with low user satisfaction and huge costs of maintaining their data, due to a lot of duplicate products.
  • Eliminated over 100k duplicate products around the world by creating an event based asynchronous deduplication service which cleaned up the redundant barcodes, reassigned the scattered vendor products to the newly merged product and archived the duplicates. 
 Skills: Java, Kotlin, Spring Boot, Hibernate, Google PubSub, Kafka, Terraform, Kubernetes, Docker, GCP, PostgreSQL, Gradle, Git, Drone CI, Spinnaker

Senior Java Developer

Delivery Hero

Transport & Logistics

>10.000 team member

The client, a global top player in the Q-commerce industry, was losing money, due to being unable to update the status of their products once the stock availability changed. 
 
  • Eliminated the risk of having outdated SKU statuses by 100% by creating a Kubernetes cronjob which used an SKU updating runner to set the statuses according to the stock events and activation dates. 
Skills: Java, Kotlin, Spring Boot, Hibernate, Google PubSub, Kafka, Terraform, Kubernetes, Docker, GCP, PostgreSQL, Gradle, Git, Drone CI, Spinnaker

Senior Java Developer

Deutsche Bank

Banking & Financial Services

>10.000 team member

The client, activating in the banking sector, was experiencing poor performance on their already existing auditing system that oversaw the changes made on the domain objects. They were also seeing long waiting times in generating audit reports. 
 
  • Saved 50% of the time spent on storing the data changes by creating an SDK to incorporate an auditing framework into the applications in order to automatically save each and every change into new designated tables 
  • Considerably decreased by 90% the time spent on extracting reports on the audited fields, by storing the data in a distributed in-memory caching database 

Skills: Java, Spring (Boot 2, Data, Batch, Quartz), Hazelcast, Hibernate Envers, REST web services, Oracle 19c, OpenShift, Docker, Artifactory, TeamCity, Maven, Grafana, Git

Team Lead - Senior Java Developer

Orange

Banking & Financial Services

>10.000 team member

The client, activating in the fintech industry, was struggling with a continuously growing portfolio and a debt collection process that was getting increasingly difficult to manage due to lacking a backend system to handle all the necessary loan products such as credit card debts, loan debts, garnishments, commissions, and more. 
 
  • Eliminated the risk of debts not being collected, by 100%, by architecting a collecting mechanism that was paying the debts and was getting triggered every time new funds were added to any of the client’s accounts 
  • Drastically increased the productivity of the sales reps, selling over 10x more loan products by designing a stable and scalable disbursement service contained in a new microservice, to validate all the eligibility conditions and then later to credit the client’s account 

Skills: Java, Kotlin Spring(Boot 2, Data, Security, Batch, Quartz, WebFlux), Microservices, Apache Kafka, REST web services, Hibernate, Oracle 19c, Redis, Artifactory, TeamCity, Gradle, Prometheus, Micrometer, Alertmanager, Grafana, Linkerd, Git, Avro, ELK Stack, Process Manager EIP

Senior Java Developer

Orange

Banking & Financial Services

>10.000 team member

The client, a fintech company, was experiencing a lower-than-expected growth in the number of clients because they were short on features such as credit cards and installment plans. 
 
  • Increased the number of transactions by over 20% and the number of users by 250k by designing an installment plan REST API to validate the eligibility status of each transaction and to generate the plan for it based on the account offers retrieved from the database 
Skills: Java, Spring(Boot 2, Data, Security, WebFlux), Microservices, Apache Kafka, REST web services, Hibernate, Oracle 19c, Redis, Artifactory, TeamCity, Gradle, Git 

Senior Java Developer

Murex

Banking & Financial Services

>10.000 team member

The client, a French capital market services provider, wasn't reaching its target in terms of number of closed trades due to a faulty contract management system that was causing contracts to stay in pending for a long time not generating any substantial income to the client. 
 
  • Increased the client’s portfolio of trades by 30% and generated over $300k extra a month by creating an integration application that was using Apache Camel routes between the client’s systems and another very popular platform. At each end of the route a messaging broker was used to achieve the trade action import in both platforms. 
  • Drastically reduced the time to close a deal by up to 50% by designing a highly accurate matching service that was allowing the two parties from the different platforms to negotiate on the trades’ attributes like the amount, the interest rate and so on. 

Skills: Java, Weld CDI, JAXB, Apache Camel, JMS, Spring Boot, Oracle 12c, Linux, Maven, Nexus, Jenkins

Senior Technical Consultant

Oracle

Internet & IT

>10.000 team member

The client, an American cloud vendor, was struggling with low sales, decreasing revenue and difficulties raising awareness about their products due to an inefficient advertising system among enterprises. 
 
  • Ensured 100% clarity into the client’s products, by building from the ground up a PoC application to give a 360-degree perspective of the key points of the client’s tools by showcasing fault tolerant databases and easy to use enterprise development frameworks, building REST APIs out of plain tables while integrating with cloud solutions for content management. 
Skills: Java, Oracle Application Development Framework (ADF), Oracle Database 12c, Oracle WebCenter Portal 12c, Oracle Content & Experience Cloud, JavaScript, jQuery, HTML, CSS 

Java Developer

AJG via Endava

Insurance

>10.000 team member

The client, one of the top 3 insurance brokerage companies worldwide, was unable to satisfy the continuously growing demand for insurance products and was wasting huge amounts of resources while trying to keep up due to using a slow and inefficient system for issuing policies. 
  • Greatly improved underwriters' productivity by more than 6x and generated over 10k insurance policies by developing and integrating over 10 new products, configuring the entities and the application server. Kept consistency by using atomic transactions over the mutating operations upon the database. 
Skills: Java, JavaScript, CSS, HTML, XML, Tomcat, Hibernate, MySQL

Java Developer

Government and Public Services

50-250 team member

The client, a university institution, was struggling to organize the schedule for their increasing numbers of students and new classrooms while at the same time trying to integrate unplanned spontaneous classes or exams due to still using paper documents to do the scheduling, a slow system prone to errors. 
 
  • Eliminated the booking conflicts by 100% by streamlining the reservation process and creating an Android application to book the classrooms, which was using Google Sign in 
  • Reduced the time gaps saving over 30 hours a week by creating a quick booking feature that was scanning a QR code placed on the classroom's door, opening a view with the schedule for it. 
Skills: Java, Android Studio, Gradle, Git, Firebase Cloud Database, Google Sign-In 

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