Patryk Glowienko

Senior Backend Engineer · de-facto Tech Lead

10 years building distributed systems with Kotlin, Kafka, and Kubernetes across fintech, healthcare, and logistics.

EU citizen · authorized to work across the EU/EEA · based in Amsterdam

What I do

I design backend systems that teams can actually maintain. From architecture decisions to production debugging to growing engineers around me.

⚙️

System Design

Event-driven architectures, saga patterns, service-to-service communication. Turning complex business processes into maintainable distributed systems.

🔍

Production Debugging

Finding and fixing the bugs that hide in production — timezone edge cases, transaction isolation issues, silent failures in distributed systems.

🧑‍💻

Technical Leadership

Coaching developers, running knowledge shares, designing team standards, and making architecture accessible to everyone on the team.

Experience

10 years building backends — from trainee to tech lead.

2023 — now

Senior Software Engineer · Client Lead

Sytac → Ahold Delhaize · Amsterdam

Event-driven logistics systems (Kotlin, Kafka, K8s). Architecture design for route planning and order management. Coaching developers, supervising migrations, leading knowledge shares. Promoted to Client Lead in 2025.

2022 — 2023

Backend Engineer

Quin · Amsterdam

Healthcare platform — multi-country support, architecture design, API redesign with cache & resilience fallback. Led small dev team. Introduced unified integration testing with Testcontainers. Deployed via Helm, Kubernetes, Argo CD.

2020 — 2022

Software Engineer

TouK → Allegro.pl · Warsaw

Building for Allegro.pl — the largest e-commerce platform in Poland. Big dataset invoice processing, DDD, event-driven microservices. Google BigQuery, Kafka, high-traffic fault-tolerant systems. Created new microservices from scratch, shipping carrier integrations.

2019 — 2020

Java Software Engineer

Monedo Holding GmbH

Fintech — loan payments backend across 10+ microservices, multi-country. Payment providers integration (SEPA, Sofort, Mymoid), RabbitMQ, database refactoring for payment transactions.

2018 — 2019

Java Developer

PKO Finat (PKO Bank Polski) · Warsaw

Banking — REST API for financial orders from scratch, DDD approach, IPKO mobile app features. Complex business validations, login flows, pension system maintenance.

2016 — 2018

Junior DevOps Engineer · Trainee

Samsung Electronics Polska · Warsaw

SHealth challenges & insights backend, scheduled messaging for mobile app, REST API with OAuth2. Started as trainee, promoted within a year.

Highlights

Selected impact across architecture, delivery, and people.

2026

Kotlin Trainer — 3 full-day sessions for Oracle developers

Designed and delivered 3×8h Kotlin training with exercises and theory for developers transitioning from Oracle to backend.

2026

Supervised major Kafka migration

Cross-team alignment, story creation, migration documentation. Coordinated end-to-end without breaking production.

2026

Designed and implemented Vehicle Availability component from scratch

Domain entities, flows, and DB layer for a new version of the transport management system — whiteboard to production-ready.

2025

Promoted to Client Lead

Onboarded 4 engineers into Ahold, helped 3 pass interviews. Took ownership of Sytac-Ahold relationship alongside engineering work.

2024

Built unified REST clients library

Eliminated code duplication across 4 services. Unified error handling decoupled from third-party API changes — used by entire team.

2024

Saga pattern for order cluster sync

Designed cluster state entity with stages and persistence — increased visibility of complex business processes and better debugging for planning services.

2024

Conference speaker & technical writer

Sytac DevJam conference presentation. 3 technical articles published on distributed systems, MongoDB, and Kubernetes.

Writing

Technical articles on backend engineering and distributed systems.

April 2025

What to do if your REST call fails?

Handling failed HTTP requests in distributed systems — retries, circuit breakers, fallback strategies.

January 2025

MongoDB transactions with Spring Boot

How transactions work in MongoDB, when you need them, and how to configure them properly.

September 2024

Spring Boot config with Kubernetes

Configuring Spring Boot on Kubernetes using config maps and volumes — practical patterns.

Stack

Technologies I work with daily and bet on.

Kotlin Java Spring Boot Kafka Kubernetes Helm Docker AWS Azure PostgreSQL MongoDB Oracle DB Grafana Argo CD RabbitMQ REST APIs Event-Driven Architecture Domain-Driven Design Testcontainers