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The full decision log.

18 projects since 2006, newest first. Filter by the role I played: advisor before the build, architect during it, or engineer writing the code.

ADR-0182025 →Status: Ongoing

Decide before you build

Arpeggia Studio clients · advisor

Context
Companies about to sign a vendor contract, rescue a troubled project or replace a legacy system, with no independent view of the risk.
Decision
Structured discovery and architecture reviews: options with cost, risk and timeline impact; a risk map; an action plan teams and vendors can execute.
Consequence
Decisions made while they're still cheap to change.
My role
Co-founder, senior solution architect
ADR-0172026Status: In progress

Verifiable credentials for training

Open Badges 3.0 platform · via Arpeggia Studio · advisor

Context
Course and training providers need certificates that can be verified, shared and trusted beyond a PDF.
Decision
A certificate generator built on the Open Badges 3.0 standard, issuing both certificates and verifiable badge credentials.
Consequence
Standards-based credentials portable across platforms.
My role
Product & architecture
ADR-0162026Status: In progress

A game-show engine

Corporate client · via Arpeggia Studio · advisor

Context
A company wanted TV quiz formats (Wheel of Fortune, 1 of 10 and similar) running on desktops and tablets, without building each game from scratch.
Decision
One reusable engine that serves multiple game-show formats across devices.
Consequence
New formats become configuration, not new projects.
My role
Product & architecture
ADR-0142021–2026Status: Live

Contract Lifecycle Management

INNIO · via Inspeerity · architect

Context
Contracts across the company were configured inconsistently and their real costs were hard to predict.
Decision
A CLM platform that configures contracts correctly and simulates their costs before signing.
Consequence
One controlled, unified way to contract, with predictable numbers.
My role
Engineering Team Lead & Lead Architect
ADR-0132021Status: Delivered

Self-service SIM provisioning

iBasis IoT (Simfony) · via Inspeerity · architect

Context
Customers depended on the provider to provision SIM cards, register them with operator billing and set tariffs.
Decision
A new, user-friendly SaaS version exposing full provisioning, billing registration and tariff management as self-service.
Consequence
Customers provision end-to-end on their own.
My role
Lead Architect
ADR-0122020–2021Status: Delivered

Courier performance dashboards

DHL (via TIF) · via Inspeerity · architect

Context
Operations needed to see courier KPIs and costs to make delivery more efficient.
Decision
Dashboards consolidating courier work and operational indicators.
Consequence
Costs and performance visible and controllable.
My role
Lead Architect
ADR-0112020Status: Delivered

One restaurant system, many POS vendors

LineTen · via Inspeerity · architect

Context
A restaurant ordering product had to work with whatever POS system each venue already used.
Decision
A restaurant system with an integration layer for multiple POS vendors.
Consequence
A more flexible, more sellable product.
My role
Lead Architect
ADR-0102019–2020Status: Delivered

Rail tickets across Europe

trainplanet.com · via Inspeerity · architect

Context
The company wanted a new sales channel: search and buy rail connections across Europe online.
Decision
A ticket sales web platform integrated with the existing sales system.
Consequence
A new revenue channel open to every European traveller.
My role
Lead Architect
ADR-0092015–2018Status: Delivered

B2C platform for 14 countries

DPD Group · via eo Networks · architect

Context
A B2B parcel carrier needed a direct relationship with parcel recipients across 14 countries and 13 business units with different rules.
Decision
Three portals (customer hub, parcel redirection to Parcel Shops/PUDO with tracking, returns) on Spring Boot microservices, configurable per business unit.
Consequence
One platform, local behaviour per country.
My role
Java Architect & Team Lead: architecture, infra sizing, team
ADR-0082014–2015Status: Delivered

One portal for every labour office in Poland

Ministry of Labour & Social Policy · via eo Networks · architect

Context
Hundreds of county and regional labour offices ran separate, ageing portals.
Decision
Replace them with a single nationwide Liferay platform with shared search and workflows.
Consequence
A unified public service across the country.
My role
Liferay Architect & Team Lead
ADR-0072013–2014Status: Delivered

Insurance calculators without developers

Aviva and Inter Ubezpieczenia · via eo Networks · architect

Context
Two separate insurers, Aviva and Inter Ubezpieczenia, each needed a development cycle for every new premium calculator or policy offer.
Decision
For each company, a user-friendly builder for calculators and offers on Liferay and Spring Webflow, integrated with its policy systems.
Consequence
Business teams launch offers themselves.
My role
Liferay Architect & Team Lead
ADR-0062013Status: Delivered

Liferay expertise on demand

Lufthansa · via eo Networks · architect

Context
An internal Liferay platform with no in-house experts to support it officially.
Decision
Expert consulting and delivery of critical fixes to the platform.
Consequence
A business-critical platform kept healthy without building a team.
My role
Liferay expert
ADR-0052012–2013Status: Delivered

Rebuilding a film portal around its community

Stopklatka.pl · via eo Networks · architect

Context
The business wanted to reinvent itself around its film database and an engaged user community.
Decision
A complete new portal with ratings and user interactions, plus a large data migration from the old site.
Consequence
The film database exposed and a community built around it.
My role
Liferay Architect & Team Lead
ADR-0042011–2012Status: Delivered

PUE ZUS e-services platform

ZUS (Social Insurance Institution) · via eo Networks · engineer

Context
Contribution payers needed an online platform to manage their social-security contributions.
Decision
Co-built the PUE ZUS platform.
Consequence
Contributions managed online.
My role
Member of the delivery team
ADR-0032011Status: Delivered

Portal of the Polish EU Presidency

Polish EU Council Presidency 2011 · via eo Networks · engineer

Context
Poland's 2011 Presidency of the Council of the EU needed its official web portal.
Decision
A Liferay-based portal, alongside a series of Liferay deployments for city halls, NGOs and a travel agency.
Consequence
The official online presence of the six-month Presidency.
My role
Liferay developer & architect
ADR-0022010Status: Delivered

Opening the Patent Office to the public

Polish Patent Office · via eo Networks · engineer

Context
The Patent Office of the Republic of Poland needed a public portal with attractive, easy-to-manage content.
Decision
A content management platform built on Java EE (EJB), tailored to the office's publishing workflow.
Consequence
A modern public portal maintained by the office itself.
My role
Java Developer
ADR-0012008–2009Status: Delivered

Enforcement titles, one application

Getin Bank (SOTE) · via eo Networks · engineer

Context
Banks handled enforcement titles with inconsistent tools.
Decision
A single Spring-based application to process enforcement titles.
Consequence
One consistent process across banks.
My role
Java Developer
ADR-0002006–2008Status: Delivered

A CMS framework, 100+ times over

Future4net · engineer

Context
Small businesses each needed a website, fast and cheap to maintain.
Decision
A reusable PHP/Smarty/MySQL CMS framework instead of one-off sites.
Consequence
More than 100 production deployments from one codebase.
My role
Team Leader & PHP developer

Facing a decision that's expensive to undo?

A new product, a troubled project, a legacy system or a vendor proposal on your desk. Let's talk it through for 30 minutes before you commit budget.

Book a free consultation →piotr.filipowicz@arpeggia.studio