Software architect for hire

Hard problems,
shipped.

I'm Lasse Numminen. For nearly twenty years I've built the software other teams get stuck on: AI systems, game engines, hardened backends. I've done it as a CTO, technical lead and consultant. Now you can hire that experience directly through my company, Mercenary Software.

Experience
~20 years
Domains
AI · Backend · Games
Base
Finland (EU), remote

What I do

Three fields that rarely overlap in one person. Hire me for any of them, or for the problems that sit in between.

AI & LLM engineering

Agent harnesses, deterministic LLM programming, and advanced RAG with careful data ingestion. I build AI systems that produce repeatable results. When your data can't leave the building, I deploy them self-hosted or fully air-gapped.

  • Agent harnesses
  • RAG
  • Self-hosted models
  • Claude & GPT APIs
  • Python
  • TypeScript

Backend, DevOps & security

Microservices that survive production. AWS infrastructure, Kubernetes, Terraform and CI/CD pipelines, with security hardening throughout. That includes regulated industries under ISO 13485, GDPR and HIPAA.

  • AWS
  • Kubernetes
  • Terraform
  • CI/CD
  • .NET
  • Node.js
  • Security hardening

Games & engines

From gameplay code down to the metal. I've shipped mobile games, restructured a live MMO client, and built rendering and physics at engine level: Vulkan, render graphs, deterministic networked physics, tooling.

  • Unity
  • Unreal Engine
  • Bevy
  • Vulkan
  • C#
  • C++
  • Rust

Track record

Client and employer names are withheld on purpose. Ask me about any of these and I'll gladly go deeper in person.

  1. 2025 —

    Co-founder & CTO, AI tooling startup

    Designed and built a context engine and multi-agent orchestrator: given a goal, it plans its own tasks and validation layers while a human can step in at any point. Deployable in the customer's cloud or fully air-gapped.

  2. 2024 —

    Founder, Mercenary Software

    Consulting engagements across GenAI application development, CI/CD, AWS infrastructure, Vulkan render graphs, gameplay architecture and deterministic networked physics.

  3. 2023 – 24

    Technical lead, medical software

    Led development of HIPAA- and GDPR-compliant health monitoring software for mobile, built its AWS infrastructure, and prepared the product for ISO 13485 certification.

  4. 2020 – 23

    CTO, multiplayer games company

    Owned full-stack architecture across multiple game products: Kubernetes microservices, CI/CD pipelines, AWS, and a high-performing development team I hired, built and mentored.

  5. 2020

    GPU silicon

    Tested and adjusted GPU silicon algorithms in software for a major hardware vendor, working in C and C++ on frame-rendering analysis.

  6. 2019 – 20

    Senior game developer, MMO

    Restructured the client architecture of a live MMO, built a procedural map generator and a full map editor, and mentored fellow programmers.

  7. 2008 – 19

    The first decade

    Lead programmer on two shipped mobile games, founder of a web software company, POS systems specialist. I started programming at age 8 and have been paid for it since 2008.

You work with me.
Not a bench, not a rotation.

  • Direct

    One senior engineer from first call to shipped product. No hand-offs, no account managers.

  • Flexible

    Contract work, outsourced development, or a fractional architect/CTO. Whatever fits your team.

  • EU-based

    Remote from Finland. GDPR-native, comfortable with regulated industries and air-gapped environments.

Tell me what you're stuck on.

A few sentences are enough: what you're building and where it hurts. I'll tell you honestly whether I'm the right person for it.

Or use the form. It lands straight in my inbox.