Core product ownership
Commercial product ownership through growth and maturity
Long-running ownership across product, runtime behavior, and engineering flow.
home of
CarstenNilsson
Commercial impact
Scaled past DKK 10M ARR
Worked on the product as it became a core commercial driver for the business.
Technical depth
VSTO, Office interop, async, caching, profiling
Strongest when the work needs performance wins, careful debugging, and durable design.
Personal platform work
Serious personal platform work
I also build and operate private infrastructure with a strong bias toward automation, reliability, and clear operational ownership.
Positioning
Hands-on product engineering with a performance bias.
I have spent most of my career inside real commercial software, where the work is not only shipping features but making the product faster, calmer, and easier for a team to deliver with confidence.
What I actually do
Most of my work sits where product engineering meets high-leverage technical cleanup: faster runtime behavior, more predictable systems, and tooling that makes shipping easier.
Why this site exists
This is a small, durable public surface for the things that matter: who I am, what I have built, and the kinds of engineering problems I am good at solving.
What I have been growing into
Alongside my day job, I have been doing substantial personal platform and infrastructure work under `nosslin.dk`, with a focus on automation, access design, observability, and operational tooling. AI has materially expanded how much I can execute independently, and it has driven a period of unusually strong personal growth.
Selected workSee all
Ampler Charts
Commercial Office add-in product work with long-term ownership and performance focus.
Worked across feature delivery, plugin behavior, profiling, caching, async processing, and practical C#/.NET design to keep the product fast and dependable over time.
Office add-in platform and delivery tooling
Internal engineering work that improved throughput around commercial add-in development.
Contributed recurring improvements around CI parallelization, developer workflow, and supporting tooling so the team could move faster without making the product harder to operate.
NotesOpen notes
Performance work is product work
Why runtime improvements, profiling, and algorithm cleanup are not side quests when the product lives inside Office.
Delivery leverage beats busywork
Notes on the kind of tooling, CI, and workflow improvements that quietly compound into a much stronger team.
Hands-on architecture
A working definition of architecture that still stays close to code, operational detail, and product reality.