09/29/2026 updated

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100 % available

Senior Java Developer and Software Architect

Poskwitów, Poland
Worldwide
M.Sc. Eng. Chemical and process engineering, B.Sc. Eng. Computer science
Poskwitów, Poland
Worldwide
M.Sc. Eng. Chemical and process engineering, B.Sc. Eng. Computer science

Profile attachments

cv_smichalski_08_2026.pdf

About me

Consultancy and development of Java-based, high-throughput data processing systems, optimized for ultra-low latency and enhanced by custom-trained deep learning neural networks.

Java (Programming Language)Software QualityDevOpsJava ArchitecturesJava Development ToolsJDeveloperMessage Queuing Telemetry Transport (MQTT)Software ArchitectureBlockchainSystems IntegrationCloud Platform SystemKubernetes
Java Development
Over 22 years of commercial Java experience covering J2SE (1.4 to 25), Kotlin, Spring, Spring Boot, Hibernate, JPA, Servlets, REST, SOAP, Kafka, MQTT, and microservices design and development with REST and event-driven APIs.

Software Architecture
Extensive background in designing and developing distributed computation platforms, software-defined services, and high-throughput data processing systems optimized for ultra-low latency, including experience in leading and mentoring development teams.

Blockchain and Ethereum Platform
Hands-on expertise in Ethereum Platform deployments on large AWS clusters using Kubernetes, smart contract development with Solidity and Truffle Framework, DApps creation, blockchain cryptography including hashing and zero-knowledge proofs, and consensus mechanisms such as PoW, PoS, and PoA.

Database Technologies
Practical experience with Oracle, MySQL, MariaDB, MongoDB, and MS SQL in various enterprise and banking projects.

Cloud and DevOps
Working knowledge of AWS (EC2 clusters, ECR, VPC Peering), Microsoft Azure, Google Cloud Platform, Docker, Docker Compose, Kubernetes, Jenkins, and GitLab.

Testing Frameworks
Proficiency with jUnit, dbUnit, httpUnit, Mockito, Hamcrest, and Jmeter for comprehensive software quality assurance.

Messaging and Integration
Experience with Kafka, MQTT, JMS, SOAP, REST, NETCONF, RESTCONF, and MEF Sonata API for enterprise system integration.

JavaScript and NodeJS
Knowledge of JavaScript OOP, NodeJS, HTML/CSS, and web3 integration for DApps and front-end development tasks.

Camunda DMN and BPMN
Familiarity with Camunda DMN and BPMN for business process modeling and decision management in enterprise applications.

Linux and Unix Systems
Solid experience working on Linux distributions including Ubuntu, RHEL, Debian, and SUSE Enterprise, as well as Unix Solaris, including Linux BASH scripting.

Experience

Professional experience10+ years
Freelancer since2013

Languages

EnglishFluentPolishNative speaker

Project history

CEO and Java/Quant Developer

JavaDev Sergiusz Michalski
Consultancy and development of Java-based, high-throughput data processing systems, optimized for ultra-low latency and enhanced by custom-trained deep learning neural networks.

Java Developer (contributor)

HSBC Service Delivery Polska Sp. z o.o. (via MindBox)
Development and support of the services integration hub application used for private and corporate credit platform across UK and ASP region. Developing AI aided software for credit lending. Technologies: Java, Spring Boot, Power Platform Dataverse, REST + Feign, Microsoft Azure, Google Cloud Platform, Gemini 3.1 Pro, OpenAI platform.

Java Developer and Software Architect (contributor)

SDC - Skandinavisk Data Center
Design and development of distributed computations platform used for ad-hoc calculation of creditworthiness for private and corporate mortgages and loans based on various factors taken from external systems and custom banks algorithms. Technologies: Java, Spring Boot, Hibernate, REST, MS SQL, Redis, LMAX Disruptor, Camunda, Microsoft Azure.

Technical Architect (contributor)

Amartus Polska Sp. z o.o.
Architecture, design and development of the SDS Platform focused on Software Defined Services (L2VPN, L3VPN, Network Virtualization) for a major global Telecom Operator and Vendor. Design and development of Ethereum Blockchain Platform based solutions for East-West product ordering, SLA management and reconciliation using smart contracts between telecom carriers equipped with MEF Sonata API. Technologies: Java, Spring Boot, Hibernate, REST, MySQL, L2VPN, L3VPN, NETCONF, RESTCONF, Network Virtualization, Docker, Kubernetes, Kafka Messaging, Ethereum Platform, OS: Linux.

Software Engineering Consultant (contributor)

Amartus Limited Ireland
Software consultancy of the EMS Platform for management of the L2VPN optical devices (corporate switches using light as a transmission medium). Technologies: Java, J2EE, Spring, Hibernate, REST, MTOSI, MySQL, L2VPN, Transition Networks switches, OS: Linux.

Senior Software Engineer

Amartus Polska Sp. z o.o.
Java development of BSS/OSS solutions for a major worldwide networking corporation. Hands-on knowledge of Cisco Prime Fulfillment, Cisco Prime Fulfillment XDE SDK, Cisco Prime Order Management, and Cisco Prime Service Inventory. Technologies: Java, J2EE, Spring, Hibernate, SOAP, REST, Tibco, Oracle, Cisco IOS, Cisco IOS-XR, MPLS, L3VPN, OS: Linux, Unix.

Lead Software Engineer

Connect2Media
Team leading and development activities for server-side tasks for UK (T-Mobile, O2) and US (Verizon) telecom carriers plus internal tools development. Full technical and architectural support for the PrizePlay entertainment platform on US Verizon operator. Technologies: Java, J2EE, Spring MVC, Hibernate, JMS, SOAP, REST, MySQL, Oracle, MSIP (SMS/MMS Gateways), sophisticated multithreading algorithms, OS: Linux.

Software Engineer

Hands-On Mobile
Java developer on robust mobile content systems and on Mserver platform responsible for multimedia content distribution along multiple telecom carriers. Responsible for SMS/MMS messaging and support for SMSC messaging hubs. Billing integration with carriers via Bango, PayPal Mobile and Pay4It. Technologies: Java, J2EE, Spring MVC, Hibernate, JMS, SOAP, REST, MySQL, sophisticated multithreading and content delivery algorithms, OS: Linux.

Young IT Systems Architect

ComArch S.A.
Creating system architectures and drafts in J2EE for PTC - T-Mobile Poland projects and solutions for banking systems in the case of integrations with billing-systems. Technologies: Java, J2EE, Struts, EJB, JMS, SOAP, SOA, Oracle, OS: Linux.

Java Developer

ComArch S.A.
Responsible for creating applications and micro-applications for Era Omnix Mobile Platform (T-Mobile Poland). Technologies: Java, J2EE, Struts, EJB, JMS, SOAP, SOA, Oracle, OS: Linux, Unix (Solaris).

Java Developer - Intern

ComArch S.A.
Paid training for talented software engineers. Project: Prototype of communication platform for wearIT@work - the first robust implementation of wearable computing EU-grant project in Middle-East Europe, written in Java, supporting engineering teams for chemical, aviation and fire-safe industry. Technologies: Java, J2EE, Struts, EJB, JMS, SOAP, SOA, Oracle, OS: Linux, Unix (Solaris).

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