Hi. I'm Julian Seiss.

Software Architect, Technical Lead, and Developer from Cologne. I design systems, lead teams, and build pragmatic solutions.

Let's work together

Pragmatism is key

With over 18 years in software development, I help organisations design robust systems and lead engineering teams through complex projects. Whether it's architecting a cloud migration, writing production code, or coaching teams to deliver with confidence - I focus on outcomes that last beyond my engagement.

Software Architecture

I design and build scalable, maintainable systems — from domain modeling and service decomposition to hands-on implementation. I make the technology decisions that shape a product's future and write the code to back them up.

Java/Spring, Kafka, Kubernetes, microservices, domain-driven design

Technical Leadership

I guide engineering teams through complex projects — owning delivery, making architectural trade-offs, and building the processes that let teams ship reliably. I bridge the gap between strategy and execution.

DevOps, CI/CD, Infrastructure as Code, Terraform, GitHub Actions

Coaching & Communication

I help teams grow through pair programming, knowledge sharing, and hands-on mentoring. I translate between technical and business stakeholders, making sure everyone moves in the same direction.

AI-Augmented Delivery

I integrate AI tools into development workflows to accelerate delivery without sacrificing quality. From code generation to automated reviews, I help teams ship faster while maintaining engineering standards.

Selected projects

Tech Lead & Developer

Cloud Migration — AWS to Azure

As technical lead, I drove the strategic decision to make deployments cloud-agnostic, migrating a microservice ecosystem from AWS ECS to Kubernetes. I chose Kafka over Kinesis for cross-cloud flexibility and designed a domain-vertical decomposition that replaced tangled service dependencies with clean, asynchronous communication between bounded contexts. The result: a system that deploys to any cloud provider and scales independently per domain.

Java/Spring, Kubernetes, Kafka, AWS, Azure, Docker, Terraform, microservices

Tech Lead, Architect & Developer

Enterprise Identity Management — Keycloak Rollout

I led the architecture decision to replace a fragile custom-built IDM with Keycloak and developed the custom Salesforce-backed user provider from the ground up. I guided the rollout across 20+ countries for both B2B and B2C customers, built the monitoring and alerting pipeline, established security practices including regular threat modeling and penetration testing, and actively resolved production incidents to keep the system running smoothly.

Keycloak, Java, Salesforce, OAuth 2.0/OIDC, ELK, Docker, security assessments