Engineering

Over two years running engineering hiring at the firm, we made about twenty senior engineering hires. Some were transformative — engineers who raised the quality of everything they touched. Some were neutral — competent contributors who did what was asked and not much more. A few were net negatives. Looking back, the correlation between interview performance and outcome was weaker than I’d expected. The things that predicted good hires were visible in the interview, but we weren’t consistently measuring them. ...

The startup had been good. We’d grown from twelve people to forty, shipped something real, and the technical foundations were solid. But the Series B had brought in a new leadership layer, the founding team’s velocity calculus had changed, and I found myself doing more coordination than building. I’d been at this inflection point before — at the institution, actually — and I recognised what came next. The new role was at a well-established European financial technology firm. Structured, profitable, engineering-first culture, around 400 people. Not a startup. Deliberately not a startup. ...

The fintech startup started using RFCs (Request for Comments documents) when we hit seven engineers and decisions stopped being made naturally in conversation. Before RFCs, we’d build something, present it, discover disagreement, and partially rewrite. The disagreement was always there — we just discovered it late. RFCs in theory: write down what you’re proposing before building it, get feedback, align, then build. RFCs in practice, initially: long documents that people didn’t read, discussions that went in circles, and decisions that weren’t really made. The format that fixed it took six months to evolve. ...

The standard startup narrative is that small teams move fast because they cut process. No PRD approval chains, no design committee sign-off, no six-week delivery timelines. Just engineers and a product idea, shipping. That narrative is true as far as it goes, and incomplete in important ways. The startup I joined from 2019 to 2021 was fast for reasons that went beyond “we skipped the bureaucracy.” Understanding those reasons changed how I think about engineering productivity in any context. ...

The fintech startup hit the platform question about eighteen months in. We had product-market fit, we were growing, and the engineering team was doubling every six months. The systems that had worked at ten engineers were showing strain at twenty-five. The question became: dedicate engineering time to platform work, or keep all capacity on product features? This is a hard question. The people who get it right aren’t smarter — they’re clearer about what they’re actually trading off. ...

I joined the large financial institution expecting to find bureaucracy that slowed down engineering. I did find that. I also found something I didn’t expect: certain constraints imposed by regulation, scale, and risk aversion produced genuinely better engineering decisions than I’d been making at the smaller trading firm. This is about the non-obvious lessons. ...