About Antonijs
Senior Backend Engineer with 15+ years of experience combining High-Scale engineering with deep domain expertise in Fintech & Lending. Proven track record of architecting 3,000+ RPS reactive systems and delivering business-critical financial modules (Payments, Transactions, Risk Engines) autonomously. Expert in Java 21, Kotlin, Spring and PostgreSQL performance tuning, focused on shipping production-ready architecture in fast-paced environments.
English
Native or bilingual
Latvian
Native or bilingual
Polish
Fluent
German
Basic
Remote only
Primarily works remotely
Experience
- Ahold DelhaizeSenior Java/Kotlin DeveloperMarch 2022 - Today (4 years and 3 months)Amsterdam, Netherlands
- High-Performance Migration: Spearheaded the migration of REST services from MuleSoft to high-performance Kotlin/Spring Boot services, leveraging Coroutines for seamless MongoDB/Postgres integration. Some services currently handle 3'000+ requests per second, scaling efficiently during peak hours, integrated with Kafka and third party services.
- Data Ingestion Optimization: Architected a modernization strategy migrating the previous MongoDB pipeline to a Kafka-driven PostgreSQL architecture, utilizing table partitioning and the COPY command to ingest 100+ million records in under 60 minutes—slashing processing time by 80% (from 5 hours).
- Took full ownership of the development process, including writing comprehensive unit, integration, and end-to-end tests. Additionally, optimized scaling configurations and ensured the MongoDB cluster's resilience under heavy load by monitoring cluster performance and fine-tuning indexes for all collections. These efforts resulted in substantial cost savings compared to the previous MuleSoft implementation, which required 20-40 pods and incurred significant database expenses due to indexing/scalability inefficiencies.
- Engineered a robust Spring Integration-based service responsible for the weekly import of over 100+ million records into MongoDB within a tight 5-hour overnight window. This service has operated flawlessly for over two years, ensuring uninterrupted data import from CSV files generated by a machine learning-powered marketing tool for a grocery retail store.Managed Kubernetes deployments with ArgoCD, implemented comprehensive monitoring with Prometheus/Grafana, handled incident response and on-call duties.
- Technologies and Tools: Java 21, Kotlin, Coroutines, Spring 6, Spring Boot 3, Microservices Architecture, Spring Integration, Spring Data, REST, Kafka, Hibernate, Elastic, Prometheus, Grafana, MongoDB, PostgreSQL, JUnit, Testcontainers, WireMock, Kubernetes, GitHub Workflow, Docker, K8S, ArgoCD, Azure
- Wandoo FinanceSenior Java DeveloperOctober 2020 - March 2022 (1 year and 5 months)Riga, Latvia• ● Contributed to the ongoing development and enhancement of a leading fintech platform, focusing on core financial services such as payment processing, transaction management, and the integration of various payment methods.• ● Designed and implemented new software features and modules, ensuring secure and efficient handling of financial data.• ● Investigated and implemented technical solutions to address challenges specific to the financial domain, such as regulatory compliance, security, and scalability.• ● Played a key role in integrating with external financial systems, including payment gateways, banking APIs, and other third-party services.Technologies and Tools: Java 17, Spring 5, Spring Boot 2, Spring Data, REST, GraphQL, Hibernate, RabbitMQ, Activiti BPM, Graylog, PostgreSQL, TDD, JUnit, Spock, Testcontainers, Docker, WireMock;
- Credit SuisseSenior Java DeveloperJanuary 2020 - September 2020 (8 months)Zürich, Switzerland• ● Developed and implemented new features for core banking systems within a large financial institution, adhering to strict security and compliance standards.• ● Gained valuable experience working with complex financial data and regulatory frameworks in an Agile environment.• ● Contributed to the improvement of existing systems and the delivery of new functionalities to meet evolving business needs within the financial sector. Technologies and Tools
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Education
- BScRiga Technical University2013BSc
Certifications
- Advanced TDD and RefactoringUncle Bob Consulting LLC.2018
- Effective Coding Principles and Patterns in Modern Java 8DevChampions2017