Резюме Java developer

Bogdan *** |

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1.5 years of developing experience, inc. microservices and feature implementation.
EXPERIENCE

Pastebin | Java Developer
A system for storing blocks of text and convenient sharing of these blocks by links

● Features

○ Blocks of text and links are deactivated after some time and removed from the system. The user

can specify exactly when this happens

○ A user can send a link to this block to another user, who will see the same block of text when they

click on it

○ The user can create a block of text and upload it to the system

● The development process

○ Developed the main functions of the application
○ Optimized performance of the resource receiving algorithm by ˜98 ( from ˜5 to ˜0.1 s )
○ Resolved 13+ production issues of critical priority in a system where every component is critical
○ Improved uniqueness of reverted links, resulting in a positive user experience
○ Added an offline hashing generation mode, increasing performance by approximately 80% (from

~1.5 to ~0.3)

○ Optimized hash generation algorithm performance by approximately ˜99 (from ˜1.3 to ˜0.01 ( the

minimum value )).

● Stack: Java 17, Spring Boot, Nginx , Redis, PostgreSQL, Wasabi Cloud Storage ( ≈ AWS Amazon S3 (

AWS SDK ) ), Hibernate

Emergency Notification System | Java Developer
A system for quickly sending important messages to a group of users at once

● Features

○ Sending notifications to any device of the recipient automatically when sending notifications to the

whole group of recipients

○ Creating notification templates and configuring the required receivers
○ Loading users with contacts via .csv file

● The development process

○ Migrated infrastructure ( code ***e ) from monolith to microservice architecture
○ Optimized time to send notifications to many contacts by ˜50 ( from ˜23 to ˜11 s )
○ Added a guarantee of receiving messages to specified users
○ Adapted the application for high loads ( ability to handle 1M people ), which gave a performance

boost of ˜90 ( from ˜100k to 1M )

○ Added message resend function (in case of server crash), which has a significant impact on user

experience

○ Reducing the delay time of the request acceptance function
○ Adding load balancing to optimize the application for ˜70 in overall application performance
○ Improved loading times and overall performance of the main panel
○ Reduction of file upload delay time by ~60% (from ˜3 to ˜1 s)

● Stack: Java 17, Spring Boot, Kafka, Google SMTP, Nginx, Redis, PostgreSQL, Hibernate

Web Crawler | Java Developer
A system for indexing all web pages on the Internet

● Features

○ Makes a quick search of pages by keywords
○ Parses all pages, pulls links to other pages and repeats the process
○ Pulls keywords from all web pages and associates pages with them in the data***e

● The development process

○ Optimized the overall keyword search by ˜88 ( from ˜2.7 to ˜0.3 s )
○ Highly reliable services and search algorithm developed
○ Developed an add data***e with keyword and url mapping for potential sites
○ Added a link-by-link web site workaround guarantee, actually using an architecturally cyclic graph
○ Added page deduplication service, which gave a significant increase in optimisation in the overall

performance of the application

● Stack: Java 17, Spring Boot, MongoDB, PostgreSQL, Hibernate