Open to opportunities

Dominik User

@dominikuser3

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Senior FinTech software engineer specializing in secure, real-time Java and AWS systems.

Poland

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What I'm looking for

I seek backend/cloud roles building secure, high-throughput financial systems with strong engineering practices, CI/CD, and opportunities to own architecture and scalability.

I am a Senior FinTech software engineer with 10+ years of experience building secure, scalable, real-time financial systems using Java and AWS. I focus on designing production-grade microservices, API security, and high-throughput transaction processing.

I've migrated monoliths to Hexagonal microservices, implemented monitoring with AWS CloudWatch, and delivered systems processing over 1,000,000 transactions daily and averaging 400,000 requests per day. I prioritize reliability and SLA compliance in regulated environments.

My background includes full-stack and big-data work—building Airflow pipelines, Apache Spark processing, Kafka streaming, and anti-fraud modules with AML checks. I have hands-on DevOps experience with CI/CD, Docker, Jenkins, and infrastructure automation.

I hold AWS certification and engineering degrees, and I continually expand my skills by building personal projects (Golang REST APIs, Postgres, GitHub Actions) and completing focused courses to stay current with modern backend and cloud practices.

Experience

Work history, roles, and key accomplishments

Current

Java Developer – Financial Systems

Current

B2B Network

Jan 2023 - Present (2 years 11 months)

Designed and implemented high-performance, secure microservices for financial systems, migrating monolith modules to hexagonal microservices and supporting avg. 400,000 requests/day and over 1,000,000 transactions daily while ensuring SLA compliance via AWS CloudWatch monitoring.

Spring Boot AWS Cloudwatch Microservices Transaction Processing API Security

Golang Engineer

Personal Project

Jan 2024 - Jan 2025 (1 year)

Designed and implemented a lightweight REST API and Postgres-backed task management app, implemented CI/CD with Docker and GitHub Actions, and focused on clean, modular architecture for maintainability.

Go Postgres Docker GitHub Actions REST APIs CI CD

Full-Stack Developer

Jan 2021 - Jan 2023 (2 years)

Developed scalable big-data applications and migrated sensitive medical datasets to AWS Airflow pipelines, improving continuous processing throughput by 40–55% and building secure data workflows processing up to 1TB per DAG.

Spring Boot Apache Spark Elasticsearch AWS Apache Airflow Jenkins Maven

Full-Stack FinTech Developer

NetGuardians

Jan 2020 - Jan 2021 (1 year)

Built anti-fraud banking modules and AML checks, managed real-time back-end processing with Apache Kafka and Spark, and delivered front-end features in Angular to improve fraud detection capabilities.

Fraud Detection Apache Kafka Apache Spark Spring MariaDB Angular AML

Full-Stack Developer

KartGIS

Jan 2017 - Jan 2020 (3 years)

Delivered software solutions for water suppliers, engineered REST APIs and integrations serving over 1,000,000 active users/month and implemented CI/CD practices for regulated B2B environments.

Spring Boot REST APIs OAUTH2 JWT PostgreSQL Hibernate AngularJS CI CD

CI/CD Engineer

Deltavista

Jan 2016 - Jan 2017 (1 year)

Optimized deployment and environment management by creating custom Jenkins scripts and automation to streamline build and release processes for internal server management applications.

Jenkins Groovy Docker Ansible AWS Apache Kafka CI CD

Enterprise Software Engineer

Streamsoft

Jan 2015 - Jan 2016 (1 year)

Developed ERP modules in Java to enhance business processes and collaborated on database solutions using PostgreSQL, delivering enterprise-grade features for finance customers.

Java 8 Spring Hibernate Pl SQL PostgreSQL ERP Backend Engineering

Education

Degrees, certifications, and relevant coursework

Warsaw University of Technology

Master of Science, Computer Science

2017 - 2020

Completed Master of Science in Computer Science with coursework in cryptography, distributed systems, databases, and security; received a scholarship for academic excellence.

Pedagogical University of Cracow

Bachelor of Science, Computer Science

2014 - 2017

Completed Bachelor of Science in Computer Science with coursework in cryptography, distributed systems, databases, and security; awarded a scholarship for outstanding performance.