Writing
Field notes from twenty years of building regulated systems: streaming, fraud prevention, energy infrastructure, and what leading engineers through all of it actually costs.
- AI Writes the Code. Review Is Now the Bottleneck.
Upgrid merged 526 PRs in October, half opened by coding agents. Careful human review stopped scaling. Here is the gate we built instead, and what it still misses.
- AI Agents Keep Deleting Production. A Bank Would Have Stopped Them.
An AI agent deleted PocketOS's production database and its backups in nine seconds. Why these incidents are access-control failures, and the bank controls that stop them.
- REA Can Reverse Engineer Anything. It Still Can't Hack Your Bank.
REA hit GitHub trending and Photoshop clones went viral. Why AI reverse engineering can decompile your banking app but still can't touch the ledger.
- Building the Company Brain at Upgrid
How I built Clara, Upgrid's read-only Slack agent over our data, docs and code — and why the hard part was deciding what it could never do.
- Senior vs Staff vs Principal Engineer: It's About Ambiguity
What separates junior, senior, staff and principal engineers isn't raw skill. It's how much problem and solution ambiguity you can take on, and who finds the problem.
- Shipping at Upgrid
Merge to main, live in about five minutes. How I ship at Upgrid: 2,300+ merged PRs, a small team, and a cadence that tripled this year.
- Engineering at Upgrid
Next.js, Supabase, Linear, Steep, PostHog, Better Stack. A tour of the Upgrid stack — how a small team ships Swiss energy billing without a microservice estate.
- Building Upgrid
Co-founding Upgrid as CTO: a Swiss energy-community platform where billing law, metering data, and go-to-market share the same correctness bar as fintech.
- Rebuilding Fraud Prevention from Scratch in Six Months
How N26 replaced a static rule engine spread across dozens of microservices with a stateful Apache Flink pipeline in six months: new-rule lead time from 4 weeks–6 months to ~2 weeks, payment to decision in ~52ms.
- Say Yes First
A product engineer brings a small tooling idea to platform. The default response — no, not now, here's why it won't work — builds a wall. There's a better one.
- I Hardly Debug Anymore
I used to relaunch the app five times to check one change. TDD felt like homework until the feedback loop clicked — now tests are how I think, not what I do after.
- Stop Complaining About Code Freezes
Code freezes feel like arbitrary bureaucracy — until you're the one on call during the holidays. The real reason companies do them isn't what most engineers think.
- Engineering at N26
Nine thousand containers, two hundred microservices, one licensed EU bank. An insider tour of how N26's stack actually worked — and the parts we hadn't finished yet.
- Straight Out of the Bootcamp
You finished the program. Now what? Stop collecting certificates. Build something recruiters can click. Prepare like interviews are the job — because for a while, they are.