Peter den Haan

Software architect and technical lead

I lead a small engineering team on a low-code GenAI product at Accenture, and review the core of what the wider project ships. Before this I helped build a quantum computing practice from nothing. Before that I spent over a decade as a church minister. Before that I co-wrote Java books and led a development team. Further back, a doctorate in theoretical physics, which is still how I think.

What connects them is a habit of going deep into unfamiliar territory and coming back able to explain it.

I care about designs that survive contact with reality, and about helping developers become the kind of engineer people trust with hard problems.

The work that matters most starts before anyone is sure what to build.

Peter den Haan
Dutch · UK-based · English, Dutch, Spanish, German

Career

Three careers, or one, depending how you count.

Filled bars are full-time work. Where two overlap, a single role sat in both threads. Outlined bars ran alongside it: the doctorate finished in spare time, and the writing, teaching, speaking and mentoring that never really stopped.

Three stretches still do a lot of the work. Two years of Clojure at QFI is where I learned the difference between simple and easy. Quantum computing, twenty years after the doctorate, was the last time I took a field apart and rebuilt it from scratch. The ministry decade did something different: a weekly obligation to take something profound and make it clear and practical to people with no background in it, which is most of what design review turns out to be.

Now

Since October 2024 I have led the technical side of a low-code generative AI product. TypeScript and React at the front, Python, FastAPI and Postgres behind it. I shape the architecture and design with the team, lead the engineering day to day, and am the reviewer for most of the core product. The wider project team spans the US, the UK, France, Luxembourg, Germany, Poland, Romania and India. Alongside that I contribute to Accenture's Centre for Advanced AI and to the UK Health & Public Service Data & AI practice.

The tools matter less than people think, including the ones that write the code. A lot of what I build now is written with AI assistance, and it raises the bar for everything around it: sharper review, tests that are genuinely capable of failing, debt written down and paid rather than absorbed. Speed is only worth having if the discipline scales with it.

What I actually do is decide what to build, work out why the hard parts are hard, and make sure the people around me get better at both. Some of that is formal, some of it because people asked. I interview for the practice, and present at our weekly knowledge-sharing session more often than anyone else.

Background

  1. 2024–present

    AI/ML Computational Science Manager Accenture, Centre for Advanced AI

    Team lead and researcher. Generative AI, agentic systems, and the governance of both: evaluating agents against the NIST AI RMF and the EU AI Act, and the authority-to-operate process that follows. Led an applied research project on tensor networks for object detection in satellite imagery. Technical lead on the current product since October 2024.

  2. 2022–24

    Quantum Computing Specialist Objectivity, acquired by Accenture

    First member of a small team headhunted to build a quantum computing practice from nothing: research, client work and industry partnerships. Spoke on the state of quantum annealing at Conf42 in 2023.

  3. 2016–22

    Minister Rugby, then Leamington Spa Baptist Church

    Associate minister at Rugby. From 2018, when the senior minister left, its only one: the title did not change, the responsibilities did. Then minister at Leamington Spa. Strategy, governance and budgets with the leadership team. Weekly public speaking to an audience of non-specialists.

  4. 2013–15

    Senior Software Engineer QFI Consulting

    Two years of full-stack Clojure. Statistical, simulation and analysis tools for the NHS, built on the Theory of Constraints. Domain-driven design, functional programming.

  5. 2008–13

    Assistant Curate Church of England

    Took on the team as its only full-time pastor when all the senior staff left, with the leadership responsibilities that came with it.

  6. 1999–2005

    Principal Systems Engineer Objectivity

    Technical lead and mentor for the Java team, most of them out of conversion courses when I arrived. By the end I would have put any of them on anything — not because they knew everything, but because they knew where their competence ran out, and pushed past it only as a deliberate choice. Bespoke development for clients including Shell Finance, IPC Media, the FA Premier League (case study, PDF) and Primark. The company's public face in the wider Java world.

  7. 1997–99

    Junior Systems Engineer Radboud University

    Design and development of an ISP's back-office system.

  8. 1993–96

    Doctoral Researcher Radboud University Nijmegen

    QED renormalization in anti-de Sitter space, with undergraduate teaching alongside.

Writing and speaking

Technical reviewer and editor for Addison-Wesley, Wiley and Osborne McGraw-Hill, 2002–05. Moderator on JavaRanch.

Qualifications