David Chaava Email & Phone Number

Serbia

Microsoft CosmosDB SDK (.NET and Java SDK for Azure CosmosDB) is the development of high-performance applications of any size or scale with a fully managed and serverless distributed database supporting open-source PostgreSQL, MongoDB, and Apache Cassandra.Main achievements and responsibilities: - Improved tool for benchmarking .NET SDK;- Wrote Technical Documentation for CosmosDB Java SDL Kafka Sink Connector;- Developed samples for CosmosDB Python and Scala Spark Connectors;- Developed Java samples using OpenAI, Cognitive Search, and CosmosDB;- Developed samples for Java SDK;- Developed Bash scripts;- Developed automation using ARM Templates for launching benchmarks on multiple Azure VM’s by collecting metrics and capturing diagnostic data;- Participated in SEV3 incidents mitigation;- DB optimization research (range and composite indexes, indexing policies);- Communicated with business customers.Used languages and technologies: Java, C#, .NET, Python, Python SDK, Azure (ARM Templates, Azure CosmosDB, Kusto, Azure Blob Storage, OpenTelemetry, Azure Application Insights, Mongo VCore, Azure Cognitive Search, Azure Databricks, AAD, Azure Containers, Azure VM), Bash, Docker, Scala, Spark, Linux

Moscow City, Russia

Technical Lead & Backend EngineerATMProcessing is a transaction processing service from ATMs on NDC protocol with high load and high availability requirements.- Team Leadership: Led a team of 9 engineers- Technical Leadership: Served as the technical lead for two backend teams.- ATM Service Integration: Contributed to the integration with ATM services using low-level TCP NDC protocol.- CI/CD Process Design: Designed the CI/CD pipeline, enhancing automation and efficiency in the development lifecycle.- Monitoring and Analytics: Managed Grafana dashboards using Prometheus, ElasticSearch, SQL, and Influx data sources.- Mentorship: Mentored new developers, fostering growth and skill development.- API Development: Designed and developed robust APIs.- Performance Optimization: Conducted performance tuning, index tuning, and query optimization.- Stakeholder Communication: Collaborated with business stakeholders to meet deadlines and ensure project alignment.- Documentation: Authored and maintained technical and business documentation.- Deadline Management: Ensured project deadlines were met consistently.- Fault Tolerance: Enhanced software fault tolerance through database sync replication, async replication over Kafka, load balancing, and data denormalization.- Platform Component Development: Developed key platform components, including inter-service communication using Kafka and REST.Used languages and technologies: SberCloud, Kubernetes/OpenShift, Java, Spring Framework, PostgreSQL, SQL, Apache Kafka, Helm Charts Infrastructure as Code, Ansible, Jacoco/Codecov, Docker, Wildfly, ELK, Prometheus, Grafana, Gradle, Zabbix, NDC, gRPC

Moscow City, Russia

Lead Architect & Senior Backend EngineerProject Overview: ATMosphere is a high-load, high-availability service for ATMs monitoring and restoration automation.Key Achievements and Responsibilities:- Team Leadership: Led a team of 8 engineers.- Architectural Oversight: Directed technical vision and design for four teams.- Platform Development: Developed components for inter-service communication (Kafka with Avro), REST APIs, monitoring, and logging.- Automation Engine: Contributed to an automation engine using Activity BPMN.- Monitoring System: Created a component for hardware diagnostic data analysis.- System Integration: Ensured seamless client-backend communication for status updates.- Performance Optimization: Implemented low latency optimizations.- OpenShift Configuration: Configured Deployments, Services, Routes, ConfigMaps, and Secrets.- CI/CD Process Design: Designed the CI/CD pipeline, enhancing automation and efficiency in the development lifecycle.- Process Optimization: Enhanced team processes, workflows, and delivery methods.- Monitoring and Analytics: Managed Grafana dashboards with Prometheus, ElasticSearch, SQL, and Influx.- Custom Engine Development: Built a custom engine for business logic analysis.- PCI/DSS Deployment: Deployed infrastructure to meet PCI/DSS standards.- Code Quality: Wrote unit tests, conducted code reviews, and optimized queries.- Mentorship: Mentored junior developers.- Site Reliability: Ensured reliability and supported applications.Technologies Used: SberCloud, Kubernetes/OpenShift, Java, Spring Framework, PostgreSQL, SQL, Activity BPMN, Apache Kafka, Apache Avro, Docker, Ansible, Jacoco/Codecov, Wildfly, Redis, Gradle, Hasura GraphQL, ELK, Prometheus, Grafana, Zabbix.

Moscow City, Russia

Responsibilities— Development ATM machine monitoring and Automation service and design architecture— Code review— Mentoring— Hire backend engineersAchievements — Released new highload and hight availability ATM machine monitoring and Automation service from scratch on stack: Openshift,Java,Spring Cloud,Kafka,PostgresSql,Gradle,Activiti BPMN

Responsibilities— Development Card Reissue service for bank and design architecture— Write unit test cases— Code review— MentoringAchievements — Released new card reissue service for bank from scratch

Vladikavkaz, Severnaya Osetiya-Alaniya, Russia

Taxi Orders Distribution ServiceResponsibilities— Development taxi service and design architecture— Write unit test cases— Code review— MentoringAchievements — Released new highload and high availability taxi service from scratch on stack: Java, Spring Framework, MongoDB, Wildfly, Amazon S3;— Integration with Bank for processing client payments;— Integration with Asterisk Telephony;— Implementing high-availability features up to 99.9PadMenu for providing restaurant and cafe menus on tabletsResponsibilities— Development PadMenu service and design architecture— Write unit test cases— Code review— MentoringAchievements — Released new highload and high availability taxi service from scratch on stack: Node.js, JavaScript, Express, MongoDB, Kinitic.js, Heroku;— Released menu designer;— Released menu designer;