Kristoffer Lersveen

Kristoffer Lersveen

App developer. Native iOS and macOS, Android and the web. After hours I design and train my own neural networks.

Shipping since 2021 Developer at Arribatec aka r33hab Scroll to train

About

I build apps end to end: interface, backend, release. Swift and SwiftUI on Apple platforms, Kotlin on Android, TypeScript and React on the web. After hours I design, build and train neural networks, and the tooling that lets AI agents work with real systems. By day I build an internal developer platform at Arribatec.

Based in Norway forward pass · backprop · ship · repeat

What I do

Apps

Native macOS and iOS in Swift and SwiftUI, Android in Kotlin, web front ends in TypeScript and React. End to end: interface, backend, release.

  • Swift
  • SwiftUI
  • Kotlin
  • TypeScript
  • React

Neural networks

I design, build and train my own networks: choosing the architecture, writing the training loop, tuning until the loss curve behaves.

  • Python
  • PyTorch
  • TensorFlow
  • Reinforcement learning

Platforms

Multi-tenant platforms in C# and .NET with React front ends. Single sign-on over OIDC, versioned SQL migrations, structured logging. Containerised and shipped to Kubernetes through CI and GitOps.

  • C#
  • .NET
  • Kubernetes
  • Argo CD
  • Keycloak

AI agents

Tooling on top of LLMs: MCP servers that let agents work with real business systems, Agent SDK bots, and a 3D stage that shows agents building a project live.

  • MCP
  • Agent SDK
  • TypeScript
  • Python

Selected builds

  1. 01 Luftrom

    iOS · Swift

    A native iOS map of Norwegian drone zones, with a pre-flight check before take-off.

    Open on the App Store ↗
  2. 02 Agent Visualizer

    TypeScript · 3D

    Watch AI agents build a project live: a 3D studio where coders, reviewers and planners perform on stage.

    View on GitHub ↗
  3. 03 sts2

    C# · Python · RL

    A Slay the Spire 2 simulator in C# NativeAOT, with reinforcement learning in Python for an offline autopilot.

    View on GitHub ↗
  4. 04 nordlake

    Python · dbt · DuckDB

    A small lakehouse on Norwegian open data: Python ingest, dbt on DuckDB, Airflow.

    View on GitHub ↗
  5. 05 norapi

    Python · MCP

    A searchable registry of Norwegian public APIs for developers and AI agents, as a CLI, an MCP server and a website.

    View on GitHub ↗
  6. 06 usage-hud

    macOS · Swift · Node

    A floating macOS panel showing what Claude Code and Codex cost, read from their own local logs.

    View on GitHub ↗
  7. 07 MacUninstaller

    macOS · SwiftUI

    A native macOS app for uninstalling applications and analysing disk storage.

    View on GitHub ↗
Everything else on GitHub ↗

Commit to cluster

Every merge builds, tests and packages a container. Argo CD syncs the desired state from git, and Kubernetes rolls it out.

  1. git pushmain
  2. CIbuild and test
  3. Imagecontainer registry
  4. Argo CDsync from git
  5. Kubernetesrolling update

Stack