Product
Requirements gathering, process analysis, use cases and business domain modelling.
AnalysisUse casesDomain modelling
Curriculum Vitae
Adam Walczak
System Architect & Senior Full-stack Developer
System Architect / Senior Full-stack Developer with 15+ years of experience. Specialised in developing highly scalable and reliable transaction processing systems with agile DevOps. 5+ years in a management role.
- adam@walczak.it
- Poznań, Poland
- Polish (native), English C1
What I do
Hands-on experience across a variety of roles — from product management to development and DevOps.
Architecture
From microservices to modular monoliths and the well-balanced designs in between; advanced design patterns; Domain-Driven Design from analysis, through architecture, to the codebase.
CQRSEvent SourcingTransactional OutboxReliable MessagingDDD
Data and messaging
Modelling optimised for relational databases or a given NoSQL store; deep knowledge of transactions, concurrent processing and stream processing.
TransactionsConcurrencyStream processingNoSQL
Building software
Automated tests with JUnit, Jest, Vitest, Playwright, Gatling and JMeter.
Java 25SpringGradleTypeScriptAngularnxPython (basic)PostgreSQLCassandraMongoDBRESTRPCGraphQLKafka
Security
Authentication, authorisation and identity propagation.
OAuthOpenIDRBACAsymmetric CryptographySpring SecurityKeycloak
DevOps and HA
Orchestration on Kubernetes with Helm charts and operators (e.g. Strimzi, CloudNativePG); scaling databases; advanced CI/CD; monitoring and cloud operations.
KubernetesHelmCI/CDDatadogELKNew RelicGoogle Cloud PlatformCloudflare
SDLC with AI
Optimising documentation and context for AI (specifications, ontologies); isolated agent environments based on devcontainers.
Claude CodeCodexOpenSpecdevcontainers
Domain knowledge
ERP, CRM, MES, WMS and CMS class systems. Blockchain and cryptocurrencies. Manufacturing processes. ISO 9001 quality systems.
ERPCRMMESWMSCMSBlockchainISO 9001
Experience
Fifteen years across e-commerce, ticketing, marketplaces, manufacturing and logistics.
Sep 2025 – present
Head of Platform Engineering
Piletilevi Group · through contract in biletomat.pl
Coordinating several development teams that build systems for the whole group. Standardising how the teams work and which technologies they use, and shaping a shared vision for one ticketing platform across all group markets.
Dec 2019 – Sep 2025
CTO and System Architect
biletomat.pl · formerly ewejsciowki.pl / kicket.com
Led three development teams and drove the move from a legacy platform to modular services orchestrated on Kubernetes, with an event-driven core built for reliable, high-throughput sales. Helped the CEO prepare the company for acquisition and pass technical due diligence.
- Stack
- Java, Spring Boot, Python, Angular, PostgreSQL, Kafka, Kubernetes, Datadog
- Patterns
- CQRS, Transactional Outbox, Event Sourcing, micro-batch processing
Reference
Full text →
“Adam is incredibly motivated to create world-class IT systems. His diligence and consistency in maintaining high technical standards have earned him the respect and loyalty of our development team.”
“He played a key role in acquiring a strategic investor to merge 3 companies. Technological achievements of his department underwent due diligence audits with very high ratings.”
Maciej Wartacz
Former CEO and founder of kicket.com | ewejsciowki.pl
On my watch as CTO
millionsSold tickets
>150Feature releases
9Modular services created
3Teams built
Mar 2017 – Nov 2019
Java Developer and System Architect
Freelance · IT Kontrakt, NBC, Nextbuy
Contract architecture and development work for clients across e-commerce and enterprise integration projects. Also ran my own cryptocurrency side project.
Mar 2014 – Feb 2017
Senior Software Engineer
Allegro Group
Worked with the teams rewriting the transaction platform from a PHP monolith into Java microservices, and shared the patterns and frameworks used across the Java platform with other teams. Hands-on experience with Cassandra, MongoDB and New Relic at scale.
Reference
Full text →
“Working with Adam was very effective. He helped us develop several key services for the Allegro platform. His strong technical vision and willingness to defend his ideas during design sessions ensured we always delivered top-tier solutions.”
Piotr Szatybełko
Vice President of Technology, Allegro
In teams I worked with
~ 1 mlnTransactions daily
4Services extracted from monolith
2NoSQL DBs introduced
Mar 2011 – Jul 2013
Systems Analyst and Community Manager
Qcadoo Limited
Product management of the qcadoo MES manufacturing management system, including analysis and UI design; built the community and partner network around the project.
Jun 2009 – Jun 2011
Java Developer
Freelance
Freelanced for various companies and wrote a book on open source project funding and organisational models.
Mar 2008 – Jun 2009
Java, C++ and Perl Developer
PSI Polska
Extended and deployed the PSIwms warehouse management system for logistics centres in Poland and abroad.
2004 – present
Co-owner
WALCZAK — wooden floors · family manufacturing company
Supporting the business with IT and quality management systems.
Education
Postgraduate studies in Modern Manufacturing and Logistics Management
Poznań University of Technology — Faculty of Engineering Management
Thesis: A model of a flexible IT system for manufacturing management in small and medium enterprises.
MSc in Computer Science, Software Engineering and Databases
Polish-Japanese Academy of Information Technology, Warsaw
Diploma grade: very good. Thesis: Organisational structures and business models of open source projects.
BEng in Computer Science
Poznań University of Technology — Faculty of Electrical Engineering
Diploma grade: good plus. Thesis: A data acquisition system for industrial devices.
Availability
My capacity for new projects
Soon
Full-time Architect / Lead / CTO
Will be available for full-time employment starting from December / January.
Limited / Soon
Fractional CTO / Architect
Currently available for a dozen hours per week. Will have more time starting from December / January.
Let’s talk about your software products
Tell me about the challenges facing your business, and I’ll help your development team solve them.
Contact me →