Joachim Tworko

Building scalable backend systems for enterprise clients in banking and healthcare sectors

About Me

5+ Years Experience

Backend Development

15+ Projects

Enterprise Solutions

4 GCP Certificates

Cloud & DevOps

Core: Java & Spring

Microservices Architecture

Banking & Healthcare

Specialized Sectors

Available Now

Open to Opportunities

Senior Backend Developer with 5+ years of experience building robust, scalable enterprise solutions for the banking and healthcare sectors. Specialized in Java, Spring Boot, and microservices architecture, with proven expertise in delivering mission-critical systems for large organizations like Credit Agricole, BNP Paribas, FAB UAE and Commercial Bank of Dubai

I excel at architecting backend systems that handle high traffic, complex business logic, and strict security requirements. My approach combines clean code principles, comprehensive testing, and DevOps best practices to ensure reliable, maintainable solutions. GCP certified with hands-on experience in cloud infrastructure and CI/CD pipelines.

  • Residence Poland
  • Address Rzeszów
  • e-mail tworkojoachim@gmail.com
  • Phone +48 731 303 413

What I Do

Backend Development

Expert in Java, Spring Boot, Kotlin for building scalable, secure enterprise applications. Extensive experience with RESTful APIs, microservices patterns, domain-driven design, and event-driven architectures.

API Design & Integration

Designing robust RESTful and GraphQL APIs following OpenAPI standards. Expert in service integration (SOAP, SFTP, message queues), third-party API consumption, and building API gateways for microservices ecosystems.

DevOps & CI/CD Pipelines

Implementing automated deployment pipelines with Docker, Kubernetes, Jenkins, GitLab CI. Infrastructure as Code using Terraform. Container orchestration, automated testing integration, and blue-green deployments.

Database Design & Optimization

Architecting scalable data models for PostgreSQL, MySQL, MongoDB, Redis. Query optimization, indexing strategies, database migrations, replication, and caching layers for high-performance applications.

Cloud Infrastructure (GCP / AWS / Azure)

GCP certified with hands-on experience in cloud architecture, compute engines, serverless (Cloud Functions, App Engine), cloud storage, VPC networks, and IAM management across major cloud providers.

System Monitoring & Logging

Building comprehensive observability with Prometheus, Grafana, ELK stack. Application metrics, distributed tracing, log aggregation, alerting systems, and performance monitoring for production systems.

Clients

Collaboration B2B

How I Work
🧾 Invoicing based on B2B contract
⏱ Hourly or fixed-price billing, depending on the project
📈 Flexible scope and timeline
🤝 Available for both short-term and long-term collaborations

Clients & Partners

7+ B2B partnerships

Working Hours

~11,520 and counting

Projects Delivered

15+ completed successfully

Resume

Education

2021-2022
University of Information Technology and Management

Computer Science specialization in Software Engineering

Master’s thesis focused on performance evaluation of Spring Boot and Quarkus libraries in microservices architecture applications.

2017-2021
University of Rzeszow

Computer Science specialization in Web Applications

Participated in two student scientific clubs and completed an engineer’s thesis involving the independent development of an original web application for creating IT teams.

Experience

2022 - Current
Deviniti

Software Engineer

Technologies: Java, Spring Boot, Kotlin, PostgreSQL, MongoDB, Redis, Kubernetes, GCP

  • Architected and led development of digital onboarding platform enabling fully remote bank account and business registration with 95%+ completion rate
  • Designed microservices architecture integrating 8+ third-party services (KYC, identity verification, e-signatures) with circuit breaker patterns for resilience
  • Reduced API response times by 40% through database query optimization and implementing Redis caching layer
  • Currently developing award-winning internal employee app (2024 Employer Branding Excellence Award) serving 5000+ bank employees with features including AI chat, resource management, and gamification
  • Implemented comprehensive testing strategy (unit, integration, E2E) achieving 85% code coverage and zero critical bugs in production
2024
Appwise

Software Engineer

Technologies: Java, Spring Boot, Microservices, PostgreSQL, MongoDB

  • Developed logistics TMS system for one of Europe's largest freight companies, including mobile app for drivers and web portal for business operations
  • Built waste management platform for Alba with comprehensive CMS, route planning for collection vehicles, warehouse management, and electronic document handling
  • Implemented backend services for automated invoicing, weight tracking systems, and fleet management modules
  • Delivered new features through full development cycle including planning, implementation, testing, and bug fixing
2023
Altkom Software

Software Engineer

Technologies: Java, Spring Boot, Microservices, PostgreSQL, Kafka, Docker, GitLab CI

  • Developed medical risk evaluation module within large-scale insurance platform comprising 30+ microservices
  • Mentored 3 junior developers on best practices, code quality, and microservices patterns while conducting 50+ code reviews
  • Implemented event-driven architecture using Kafka for asynchronous processing of survey submissions, improving throughput by 60%
  • Collaborated with product team to design and deliver 5 major features within strict healthcare compliance requirements
2022
NVT

Java Developer

Technologies: Java, Spring Boot, PostgreSQL, MongoDB, REST API, WebSockets

  • Architected and built reusable Kanban board library supporting both SQL and NoSQL databases, adopted across 3 client projects
  • Developed comprehensive CRM system managing employees, inventory, warehousing, and invoicing for manufacturing client
  • Implemented real-time updates using WebSockets for collaborative board interactions with 50+ concurrent users
  • Integrated email/SMS notification system and automated billing workflows, reducing manual processing time by 70%
2021 - 2022
Whirly

Mid Full Stack Engineer

At Whirly, I worked as a Full Stack Developer on a custom IVR solution for the telecom industry. I handled both backend and frontend tasks, developed new features, fixed bugs, wrote technical documentation, and implemented automated tests. The project followed a Domain-Driven Design approach.

2020 - 2021
BNP Paribas

Junior Full Stack Engineer

Technologies: Java, Spring Boot, Angular, GCP, OpenShift, PostgreSQL, Python

  • Built cloud cost calculator for architecture team to estimate and optimize GCP infrastructure costs across 50+ projects
  • Developed document processing pipeline for AI team to prepare banking documents for ML model training
  • Deployed and maintained applications on GCP and OpenShift, gaining hands-on experience with cloud-native development
  • Collaborated with senior engineers in Agile environment, participating in daily standups, sprint planning, and retrospectives
2019
Transition Technology

Internship Full Stack Engineer

I took part in a two-month internal project focused on an office management system. I was responsible for developing features, writing technical documentation, collaborating with the team, and creating unit and integration tests.

Core Technologies

Backend & Languages

Java • 5 years - Expert
Spring Boot / Spring Framework • 5 years - Expert
Hibernate / JPA • 5 years - Expert
Microservices Architecture - Expert
REST API / GraphQL - Expert

Databases

PostgreSQL - Advanced
MongoDB - Advanced
Redis - Advanced
MySQL - Intermediate

Cloud & DevOps

Google Cloud Platform (GCP) • Certified
Docker / Kubernetes - Expert
CI/CD (Jenkins, GitLab CI, GitHub Actions) - Advanced
Terraform - Advanced
AWS / Azure - Intermediate

Additional Skills

TypeScript / Angular - Intermediate
Message Queues (RabbitMQ, Kafka) - Advanced
Testing (JUnit, Spock, TestContainers) - Expert

Knowledges

  • VAVR
  • WireMock
  • LDAP
  • TestContainers
  • Junit
  • Firebase
  • SOAP
  • SFTP
  • Figma
  • RabbitMQ
  • Apache Kafka
  • Swagger
  • H2
  • Groovy
  • Spock
  • Keycloack
  • Selenium
  • Cypress
  • AWS
  • GCP
  • Azure

Certificates

App Deployment, Debugging, and Performance

Membership ID: AGUFC95QVJEH
May 2021

Developing Applications with Google Cloud Platform

Membership ID: RJSDK64Z4EVW
May 2021

Securing and Integrating Components of your Application

Membership ID: T4R6SK32E74J
May 2021

Google Cloud Fundamentals: Core Infrastructure

Membership ID: FEHSY5XZ3P4C
May 2021

Portfolio

MobilCA

MobilCA

mobile

Award-winning internal employee app for Credit Agricole with AI chat, resource booking, and gamification

Java Spring Boot Kotlin PostgreSQL Kubernetes
MyFoodie

MyFoodie

mobile

Food delivery platform with real-time order tracking and restaurant management system

Java Spring Boot MongoDB WebSockets
Ca24

Ca24

mobile

Digital banking onboarding platform with remote account opening and business registration

Kotlin Spring Boot MongoDB Redis AI Integration
CBD

CBD

mobile

Investment portfolio management application for stocks, assets tracking, and financial portfolio optimization

Java Spring Boot PostgreSQL MongoDB
TMS

TMS (Transport Management System)

Web

Logistics platform for European freight with mobile driver app and business portal

Java Spring Boot Microservices PostgreSQL
Medical Risk Evaluation Platform

Medical Risk Evaluation Platform

Web

Healthcare insurance platform with medical surveys and risk assessment in microservices architecture

Java Spring Boot Kafka PostgreSQL
Bank assistant

Bank Assistant

devops

Cloud cost calculator and infrastructure optimization tool for banking architecture team

Java GCP OpenShift Angular
AI Agent

AI Agent

devops, web

AI document processing pipeline for banking document recognition and ML model training

Python Java GCP Machine Learning

Contact

Rzeszów

+48 731 303 413

tworkojoachim@gmail.com

Freelance Available

How Can I Help You?