I build pricing and risk engines at BNP Paribas, and products of my own.
I’m the team’s only C# engineer, and the engines run on CPU and GPU. I’ve won the bank’s digitisation competition and a Take Ownership award.
The engines run large simulation-based calculations across several asset classes. Illustrative simulated paths fanning out from one level, with one highlighted in green.
The same tests had to run on both CPU and GPU.
Winner. Digitisation · 2025. Led a team of four to win the bank’s digitisation competition, co-building a dashboard that cut a 30–40 minute data load to under 5.
Take Ownership · _nology · Q1 2026 · awarded May 2026
Work
History, then marketing, then code. Each move was towards the work I liked most.
Winner. Digitisation · 2025 Take Ownership. Q1 2026 AI Champion. 2026 I was nominated as an AI Champion, and the workflow I built is now used by several teams across the department. With that workflow I integrated a pricer in a couple of days, a job that takes an experienced engineer about two weeks.
Page load, cut by 40%. Cut page load by 40% by refactoring React components and lazy-loading assets. Key API p95, 520 ms → 230 ms. Added indexes and rewrote slow queries, starting with the API that mattered most. Mobile retention, up 30%. Fixed mobile layout and browser bugs found by a cross-browser testing pipeline.
Core Web Vitals pass rate, 62% → 88%. Scoped performance fixes with the engineers and ticketed them. p95 page load, cut by 30%. The same scoped, ticketed fixes. Where the switch started. The best part of the job was working with the engineers who built our website.
Where I’m headed
I’m working towards being a product engineer, turning new ideas into software people use every day. Three things that takes, and how far I’ve got on each.
- Close enough to users to know what’s worth building.Judgement
So far, Optegra. At Optegra, split tests and dashboards guided what the engineers built next.
- Knowing it well enough that people can rely on it.Depth
So far, BNP Paribas. Six months from zero C# to production code, in a pricing engine of around 70 projects.
- All the way, from first idea to how it gets used.Range
So far, Threshold. Threshold, from 57 user stories to a live site.
Things I make
Products of my own, from a rental calculator to a risk simulator.
Product · Data visualisation · 2026
Event-driven systems · 2026
Offline-first interaction · 2026
Prototype · 2026
Systems · API · 2025
AI product · 2025
How I work
Four habits, and where I picked them up.
- Start from a real problem.Threshold started because my friends had no clear idea what renting would cost by area. Flowtime started because Pomodoro kept cutting me off mid-flow.
- Write it down first.Before I build, I write down the problem, who it’s for, and what’s out of scope. Threshold had 57 user stories before any code.
- Ship it so it’s safe to undo.At BNP Paribas, taking a stale data dependency out of live pricing, I put the new path behind a feature flag that defaults to off, with caching and an end-to-end test nobody had asked for.
- Measure whether it works.I learned this in marketing. At Optegra, split tests and analytics dashboards showed which changes brought in consultations and guided what the engineers built next; consultation conversion rose by 15%.
- Threshold’s PRD16 April 2026
People in their 20s and 30s make the decision to move out … without a clear, honest view of what it will actually cost. Threshold’s PRD, 16 April 2026
Off the clock
What my own time looks like this week.
GitHub, the past year
1,855 contributions in the past year · Live from GitHub
Use the arrow keys to move between days.
- My training week
Monday: Full-body gym. Tuesday: Zone 2 run. Wednesday: Full-body gym. Thursday: Interval run. Friday: Full-body gym. Saturday: Zone 2, rower or bike. Sunday: Assault bike intervals. Out on a run, central London.
Cover of Dark Age by Pierce Brown
Admit one. Poster for Kiss Kiss Bang Bang (2005)
- Odd but true, from this week in history3 things that happened this week, some stranger than others. · Live from Wikipedia
1 of 3. 2 November 1947. In California, designer Howard Hughes performs the maiden (and only) flight of the Hughes H-4 Hercules (also known as the "Spruce Goose"), the largest fixed-wing aircraft ever built until Scaled Composites rolled out their Stratolaunch in May 2017. 2 of 3. 2 November 1707. Four British naval vessels run aground on the Isles of Scilly because of faulty navigation. In response, the first Longitude Act is enacted in 1714. 3 of 3. 2 November 2016. The Chicago Cubs defeat the Cleveland Indians in the World Series, ending the longest Major League Baseball championship drought at 108 years.
Personal site for Elias Bennett: the work, how I build it, and what I do off the clock. Next.js, Playwright-tested.
