Alex Ivanov Email & Phone Number

Helsinki, Uusimaa, Finland

Designing, implementing and maintaining critical services, libraries and infrastructure used by the whole Wolt engineering, including authentication & autorization service, in-house Kafka outbox solution and database Kafka connectors.Additionally, as part of Wolt global on-call team, I am responsible for reacting to and investigating the global technical incidents impacting the overall scale of the Wolt business.Working with Java 17, Kotlin, Scala + Cats Framework, Kafka, Kafka Connect, Python

Helsinki, Uusimaa, Finland

As a founding member of Wolt market fulfillment tools division, I designed and implemented from ground zero the brand new solution for catalog, assortment, warehouse, vendor invoicing and pricing management for the whole Wolt market business. Scaled the system for more than 200 Wolt markets in 20 different countries.- Authored and implemented numerous architecture decisions for assortment and promotion management, including designing the assortment publish queue system, scalable promotion scheduling framework and integrating Wolt retail order processing.- Directly responsible for improving service reliability by designing the initial system SLO and implementing related metrics, dashboards and alerts.Working with Kotlin, Spring Boot framework, JOOQ, PostgreSQL, MongoDB, Kafka, Kubernetes, AWS, DataDog, Sentry, Python and OpenAPI.

Helsinki, Southern Finland, Finland

Developing core search / document access microservices and scaling company's infrastructure for developers in the cloud.Achievements:– Designed architecture changes, rollout plans and implemented refactoring and unification of several internal legacy components; – Migrated several document search services from AWS Beanstalk to a production Kubernetes environment. Tasks included designing Helm templates, conducting load testing for the proper HPA tuning and supporting the migration in production;– Designed ides and architecture, implemented code and infrastructure changes for scaling a single shared development environment to multiple feature environments for each team. Afterwards worked with each team to help them in the transition process.

St Petersburg, St Petersburg City, Russia

Developing from scratch a storage system for business-critical application of a German automotive corporation. Application provides interfaces both as REST API and as Java Connector Architecture for legacy systems;Technology stack: Java 8, IBM Websphere, Spring Boot, EJB 3, REST, Hibernate, IBM DB2, React.JS;Achievements:- Having very tight time constraints, became familiar with IBM Websphere, EJB, JCA, DB2 and z/OS Mainframe stack, successfully designed and configured a Spring Boot application to run under that environment;- Designed and implemented a binary serializer of an arbitrary Java object for a custom protocol of several legacy client subsystems;- Optimized application, algorithms and queries to meet the SLA for online requests and for maximum processing time of batch jobs.

St Petersburg, St Petersburg City, Russia

Developing a back-end solution and a web portal for an Electronic Logging Device – telemetric hardware system for monitoring driven hours, miles and vehicle statistics of commercial buses and trucks in United States.Technology stack: Java 8, Sprint Boot, Spring Cloud, REST API, Hazelcast, Event Sourcing, JPA, Liquibase, PostgreSQL, Java Portlets, JSP.Achievements:- Participated in a migration of a monolithic backend application to a microservice architecture;- Scaling and tuning several microservices for a projected 10x increase in load – adding parallel event handlers, database query optimization, metrics, code profiling, performing load tests;- Adapting the system to run on a RedHat Openshift cloud platform – creating Docker images, integrating Elasticsearch and Kibana.

St Petersburg, St Petersburg City, Russia

Developing server-side components of a field management application for Deutsche Telekom field engineers.Technology stack: Java SE 8, SOAP, Axis2, JDBC, Oracle 12c, JUnit, Android 6.Achievements:- Refactored a legacy layer of Oracle PL/SQL stored procedures to Java – additionally improved test coverage and significantly boosted the performance;- Improved CI process based on Gradle and Jenkins.

Novosibirsk, Russia

Designing and developing several modules of a retail banking system based on 3-tier architecture.Technology stack: Java 7, Oracle 11g, PL/SQL, JDBC, Hibernate.Achievements:- Developed and released a load testing framework (data generation, different test scenarios, gathering and analysis of the results) to measure the banking system’s performance on a major Russian bank’s database;- Tuning and optimizing existing algorithms and SQL queries for a high-loaded customer bank's database;- Developed and released a new optimized background job service for a bank’s End-of-Day operation to decrease the load on the database.

Novosibirsk, Russia