Вадим

Vadim Drokov

Date of birth:
11 Jun 1991

Location:
Lviv Region

Relocation:
No

Viber(s):
[открыть контакты](см. выше в блоке «контактная информация»)

E-mail:
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Github repo with newest stuff and python scripts
https://github.com/Vadim7777777/Shop, https://github.com/Vadim7777777/form

Lead/Senior Java Developer

(last updated 29 May 2024)
Summary


With around 10 years of experience in IT field I gained an ability to solve various kind of problems in Java and became confident in my programming skills particularly in areas of J2EE and Spring and in Finance sector.

Experience


Senior Java Developer
Sep 2023 – Nov (1 year 2 month)
Luxoft USA
Project description:
A large project whose purpose was to facilitate trading in financial markets.
Achievements:
•Designed and implemented custom module to handle securities trading of following types: receive free, delivery free, receive versus payment, deliver versus payment using Spring Integration and EMS and IBMMQ. Optimized the module using caching connection factory.
•Made sure processing is concurrent using @Async and thread pool for task execution inside the integration flow.
•Utilized RxJava and WebFlux for reactive programming to manage asynchronous and event-based processes
•Implemented integration testing pipeline for new module.
•Implemented performance testing pipeline that tested the module with different types of garbage collections and memory heap sizes to ensure low latency and best performance.
•Profiled application during runtime to ensure no memory leaks present.
•Designed a robust message queue data structure to ensure efficient and ordered transaction processing in high-frequency trading scenarios.
Responsibilities:
•Developed and maintained Java applications, bugfixing, participating in daily scrum meetings
Development tools:
•IntelliJ-Idea. Gradle, IoC/DI, Java 8, JDBC/Hibernate/JPA, Spring Integration, IBMMQ, TIBEMS, REST, Git, Gitlab, Autosys.

Senior Java Developer
Oct 2019 – Sep 2023 (3 years 11 month)
GlobalLogic
Project description:
A large project whose purpose was to implement ETL data pipelines for data integration needs.
Achievements:
•Implemented rest endpoints for data pipelines: java core transformations, writing to db’s, file systems.
•Leveraging java 8 parallel stream api to implement data transformations; ensured camel’s parallel processing of a route; implemented multiple listener generation for SQS.
•Designed and implemented code generation strategy based on templates.
•Fixed difficult issues in data transformation with the help of Java Core. Found 1 bug in maven meanwhile!
•Fixed issues in CXF, Camel code. SQS. SQS module didn’t have any means to define durable subscription.
•Testing deployments on AWS, Azure and GCP.
•Received recognition for exceptional customer support, resulting in a long-term partnership with the client and new project opportunities.
•Designed and implemented complex data transformation structures that maintained data integrity across multiple systems.
•Designed an optimized data structure for batch processing to handle large datasets, allowing for parallelized processing and minimal memory footprint.
•Profiling customer routes which misbehaved.
Responsibilities:
•Developed and maintained Java applications, bugfixing, participating in daily scrum meetings.
Development Tools:
•Eclipse, IntelliJ-Idea, ESB, WSO2, Java 8 – 11, Eclipse RCP, Mulesoft, Talend, JDBC/Hibernate/JPA, Kafka/ActiveMQ, Spring Boot, Angular, React, JaxB/Jackson, CXF, Jersey, Apache Camel, Angular, JET, REST/SOAP, gRPC, Tomcat, Netty, AWS (SQS, S3, EC2), Azure, GCP, Git., Jenkins., Jira, Postman, Scrum.

Lead/Senior Java Developer
Aug 2018 - Sep 2019 (1 year 1 month)
SoftServe
Project description:
I was in charge of a large microservice project that was intended to provide a web internet security solution for various firms. The project provided customers with web antivirus tools, website trust score tools, log analyzer tools, and firewall tools that allowed the customer to monitor the usage of the internet traffic in their account. Extensive knowledge of security principles was required. Around 11000 distributed microservice instances were operating to support the traffic that came from customers.
Responsibilities:
•Optimized connection establishment which relaxes security requirement if user has old software and uses most secure cipher suite for eligible software clients.
•Designed a custom scanner which scans URLS on a page (safe search)
•Optimized threat scanning and security checks using concurrency api to speed up scanning pipeline.
•Utilizing JVisualVM to find memory leak related to open but never closed connection; application profiling.
•Implementation of rest services, business logic in spring, scala.
•Designed data structure to implement exe file scanning.
•Fixing issues: security, core, etcs.
•Administration of servers and deployments on Mesos/Marathon.
•Used data structures to represent and scan executable files efficiently, ensuring that large files were processed in parallel and without excessive memory usage.
•Designed data structures for network traffic logs to efficiently process large volumes of web traffic data while minimizing latency.
•Monitoring Vertica -> Kafka -> ELK pipeline, adding Spark like this: Vertica -> Kafka -> Spark -> ELK. Wring Spark streaming processor to show and analyze real time traffic events across whole microservices.
•Developed efficient graph structures to represent and analyze security threats in web traffic, allowing for optimized querying and analysis.
Achivements:
Eclipse, Intellij Idea, Java 8 - 11 / Scala, JavaScript, HTML, CSS, React, Spring/Spring Boot, IoC/DI, Spring Cloud, Hibernate/JPA/JDBC, gRPC, Kafka/Zookeeper, ElasticSearch/Kibana, SAML/SSO, Spark, Swagger/Open API, AWS (Route53, S3, EC2), Bare-Metal Servers, CentOS, Vertica, CouchBase, PostgreSQL, Apache Mesos, Kubernetes/Terraform, Docker, Etcd, Consul, Puppet, KeyCloak, Gatling, JMeter, Grafana, Gerrit, Postman, AWS Serverless.

Lead/Java Developer
Sep 2017 – June 2018 (9 months)
EPAM
Project description:
Large enterprise stream of projects intended to implement the functioning of an insurance company. The project idea was to migrate it to microservice architecture (to 100+ microservices) and it consists of 4 parts. First is a highly responsive workflow dispatch application that allows managing administrative approvals (using concurrency api) between different company departments; a Smart Forecasting engine that provides estimation-based decisions for each type of client, Cloud Management Application that provides professional monitoring and scalability services with alarms that integrate with Jira and pager duty; Management view application which implements 100+ views for different types of tasks. The project builds on many modern Java approaches; it supports many users and uses concurrent approval processing to approve batch of tasks.
Achivements:
•Designed and implemented concurrent approval engine that could concurrently approve 40000 documents in just 5 minutes using all 16 server CPU threads which run on a thread pool.
•Profiled application and as a result developed a custom caching ang pagination mechanism that reduced database queries and improved application response time by 500%.
•Received commendation from the client for outstanding troubleshooting skills, swiftly resolving critical production issues, and minimizing downtime.
•Implemented data structures for task approval workflows that efficiently managed and queued documents for processing, optimizing throughput under high concurrency.
•Designed and implemented efficient data structures for document tracking that minimized locking and ensured low-latency access to documents in concurrent approval processing.
•Created efficient tree-based structures to represent hierarchical task dependencies, improving workflow dispatch times and reducing approval bottlenecks.
•Managed users using Spring Security and SSO
Responsibilities:
•Participating in daily scrum meetings, implementation of new features and rest endpoints.
Tools & technology stack: Java, Concurrency API, SQL, Javascript, HTML, CSS, Zk, Mybatis/JDBC, Log4J, JUnit/Mockito/Easymock, Activity BPM, JSON/XML, EhCache, REST/SOAP, Maven, PL-SQL, Oracle, H2, RedHat, JBoss, Jetty, autosys, J2EE, gRPC.

C++/C Developer
April 2015 - Sep 2017 (2 year 5 month)
Waves Audio
Project description:
Project intended to optimize quality of audio on mobile devices: MaxxBass, MaxxTreble, MaxxVolume, Stereo imaging modules, stable volume module. I optimized modules for Arm and Ceva arthitectures with a focus on a performance.
Responsibilities:
•Participare in scrum meetings
Achivements:
•Tuned compiler flags for maximum performance.
•Profiled modules using gperf, VTune and perf. Calculates MIPS using perf counters.
•Wrote a module that calculates MPS of the audio modules.
•Vectorizing algorithms using parallel processing instructions (SIMD).
•Optimizing memory usage on a register level
•Using ASM for better utilization of CPU registers, rewriting instructions order based on it’s throughput and latency, accounting on data size and size of L1, L2, L3 cache lines, writing code accounting for out of order execution.
•Writing memory compressor engine to save memory footprint of presets in a preset management software using LZ77 and LZ78 algorithms.
•Writing a java wrapper that would call optimized functions which set presets from Java phone app.
Tools: C++, gcc, g++, CMAKE, make, visual studio, vim, gprof, perf, VTune, SIMD, Linux.

С++/Qt Developer
Nov 2013 - March 2015 (17 months)
GlobalLogic Ukraine
Project description:
The goal of the project was to develop software to show human vitals on a defibrillator on a UI using QT.
Achievements:
•Developed a module according to a speficication.
•Collaborated with the UI/UX team to revamp the user interface, resulting in a modern and visually appealing design that increased user engagement.
Responsibilities:
•Participating in SCRUM meetings;
•Implementing new UI features;
•Learning new things and consulting with the team lead;
•Creating a roadmap for self-development;
•Bug fixing;
Programming Language: C++, QT
Development IDE: Qt Creator
Source control: git
Team collaboration tool: Jira

Education


National university "Lviv Polytechnic" (Lviv)
End date 2014
Software Engineering

Language skills


English - upper intermediate
I can be interviewed in this language
Ukrainian - native

Additional Information


Personal Qualities
I write music, you can listen to it on my soundcloud https://soundcloud.com/ivan-marihuana .