• English
  • Deutsch
Analysis · Coaching · Custom Software · Zurich

From requirements
to resilient systems.

fbt Berger analyses your business requirements, empowers your team through coaching, and builds the custom software to match when you need it – on commercially usable open source, replicated via a mature, self-built and tested Raft library.

18+ yearsGoogle engineering
Analysis & coachingas core services
Own Raft corefrom scratch, Apache-2.0
Arrange a call → View services

Understand requirements.
Empower teams.

Two core services form the focus – custom delivery comes on top whenever you need it.

Core service 01

Business Requirements Analysis

Before a single line of code: your business requirements captured cleanly, questioned critically and translated into a solution that will hold. From 18 years with systems at global scale, I know which questions to ask early.

Structure, sharpen and prioritise business requirements
Assess technical feasibility, scaling and risks early
From requirement to a sound architecture decision
Core service 02

Coaching

I empower your team to ship faster and more safely on its own – with two areas of focus.

Vibe-Coding

AI-assisted development at high velocity that still produces tested, documented and maintainable systems.

Large replicated systems

Building fault-tolerant, replicated architectures – in-house, for noticeably more data security and data sovereignty.

Delivery on request

Custom software development

If you would rather hand off delivery: custom software, built on the same foundation the reference projects run on.

Commercially usable open source Own Raft library · replication User management via Keycloak Apache-2.0 / MIT · legally clean

The foundation
behind the services.

Analysis and coaching only convince with real technical depth. Four building blocks every fbt Berger project stands on.

01

Distributed Systems & Consensus

Replication, quorum, fault tolerance and linearizable consistency. The machinery that keeps systems correct across node failures – a core competency, not a bought-in add-on.

02

Own Raft Library

A from-scratch implementation of the Raft algorithm in Java 17: leader election, log replication, joint consensus, snapshotting, linearizable reads. Apache-2.0 – so it can be used freely in your projects.

03

User Management with Keycloak

No reinventing authentication: I integrate Keycloak, the established open-source standard (OIDC / OAuth2, JWT) – multi-tenant and ready to use as a preconfigured setup.

04

Commercially Usable Foundation

Exclusively permissively licensed open-source components (Apache 2.0, MIT). Legally clean to use in your product – without copyleft traps.

Three projects.
One shared core.

The references are no coincidence: fbtberger-calendar and fbtberger-kwatro both use the same self-built Raft library for their replication. That proves the capability – and shows how fast it turns into working software.

CONSENSUS CORE fbtberger-raft L F F 3-node cluster · quorum REPLICATION REPLICATION fbtberger-calendar RFC-compliant calendar system · CalDAV · iTIP fbtberger-kwatro Distributed card game · gRPC · Svelte
58
Commits · fbtberger-raft
Jun 23 – Jul 6, 2026 · 14 days
Apache-2.0 · from scratch
200
Commits · fbtberger-calendar
Jun 28 – Jul 6, 2026 · 9 days
Distributed-systems demo platform
6
Modules · fbtberger-kwatro
proto · server · client · web · raft
Demo platform, built in days
Timeframes and figures come straight from the projects' Git history.

The projects
in detail.

One reusable building block, two demo platforms that show what it makes possible.

Building block · Apache-2.0
fbtberger-raft
Period 23.06–06.07.2026
Scope 58 commits
Language Java 17
Status reusable
The consensus core – a complete Raft implementation from the ground up.

Implemented after Ongaro & Ousterhout, including the optimisations from the dissertation. This is the building block that gives client projects consistent replication across node failures.

Protocol Buffers gRPC / Netty / Hadoop RPC Berkeley DB JE Segmented WAL · CRC32 Prometheus / JMX TLS · mTLS
Leader election with PreVote & leader stickiness against partition disruptions
Cluster reconfiguration via single-step and joint consensus
Log compaction with chunked, copy-on-write snapshots
Linearizable reads via ReadIndex and lease-based
Chaos tests, JMH benchmarks and multi-transport integration tests
Demo platform
fbtberger-calendar
Period 28.06–06.07.2026
Scope 200 commits
Stack Spring Boot 3.3
Purpose Capability proof
An RFC-compliant calendar system that shows the distributed architecture under load.

A pure demo platform: built to prove skills in distributed systems and vibe-coding. It combines standards compliance with serious scaling decisions – replicated via fbtberger-raft, secured with Keycloak.

Java 17 Spring Boot 3.3 PostgreSQL Keycloak · OIDC RFC 5545 / 5546 / 4791 fbtberger-raft
iTIP fanout / fanback with RFC-5546 conflict resolution
O(1) memory usage for events with 100,000+ attendees
Federation of external principals via iMIP (RFC 6047 / 6638)
Eventual consistency with four coordinated mechanisms
Docker cluster with mTLS and quorum-aware health checks
Demo platform
fbtberger-kwatro
Period June 2026
Structure 6 modules
Stack gRPC · Svelte
Purpose End-to-end demo
A distributed multiplayer card game as a compact architecture demonstration.

A pure distributed-systems demo platform: taken end to end from protocol to web frontend. It shows how a typed gRPC interface, replicated state and a reactive UI cleanly work together.

Java 17 Spring Boot 3.3 gRPC 1.64 Protocol Buffers Svelte · Vite fbtberger-raft
Multi-module structure: proto, server, client, web and Raft integration
Typed game protocol entirely over Protocol Buffers
Replicated game state based on the own consensus core
Reactive Svelte frontend with lobby, board and scoreboard

From 18 years in Big Tech
to self-employment.

From August 2007 to February 2026 I worked at Google Switzerland GmbH on software at large scale – systems where availability, consistency and clean engineering are not optional but a given.

Since 2026 I have brought that experience together in fbt Berger – Future Build Technology Berger. As a sole proprietorship in Zurich, I build custom distributed systems for European SMEs: close to the client, without friction, on a foundation proven over years.

The phoenix in the logo is deliberate: proven engineering, set up anew.
2007–2026

Google Switzerland

Over 18 years of engineering at global scale – incl. Google Calendar, Shopping and Maps.

2026

Founding of fbt Berger

Sole proprietorship in Zurich for custom distributed software – consulting, coaching, delivery.

2026 →

Core & references

Own Raft library plus two demo platforms as documented proof of capability.

Selected roles at Google
Google Calendar

Contributed to Google Calendar

Calendar and scheduling logic at global scale – exactly the domain behind the calendar reference.

→ Calendar domain depth
Google Shopping

Designed an AI-based policy-enforcement pipeline

Automated detection of policy violations using machine learning – designed for the Shopping catalogue.

→ AI-driven pipelines
Google Maps

Helped introduce incident display

Helped shape the display of incidents in Google Maps – real-time data, visible to millions of users.

→ Real-time & distributed systems

Let's build your system.

Whether consulting, coaching or full delivery – tell me what you have in mind. The reply comes from the person who also does the building.

Write an email →
fbt Berger
Future Build Technology Berger
Riedhofstrasse 98
8049 Zürich · Switzerland
© 2026 fbt Berger · Future Build Technology Berger · Riedhofstrasse 98, 8049 Zürich