Founding Product Engineer — Python / Full Stack

The calculations work. Now make the product work for someone who did not build it.
I am assembling Axiocost’s founding team and looking for a hands-on product engineer to help turn a tested technical foundation into software that industrial practitioners can use independently. Axiocost is being developed through Senoni in the UK and France, led by Philippe Dagher.
The project
We are addressing two connected problems. Cost Engineering helps people examine quotations, cost assumptions and purchasing decisions. Value Delivery examines the work, ownership, capacity, timing and evidence behind a proposed improvement. The starting point is an existing private Python prototype, automated tests, public working-method packs and examples on fictional data—not a blank repository.
Your role
Own a coherent review experience rather than a collection of disconnected features. Work with industrial and commercial colleagues to select one useful task, translate it into a usable workflow and learn from people who did not build it. You would help shape the architecture and the product priorities, not merely implement a fixed specification.
What you would work on
Build clear interfaces for structured inputs, comparisons, source-linked evidence, missing information and recorded corrections.
Connect the interface to the tested calculation and workflow components without losing assumptions, units, revision history or the distinction between a recommendation and an executed action.
Develop appropriately scoped persistence, APIs and review records; make setup, tests and deployment reproducible for the team.
Use tests to challenge changes, including invalid inputs and incomplete evidence. Keep the application understandable and maintainable, not only correct on a demonstration.
Explore assisted document interpretation where it solves a real problem. Decide what should be deterministic, what could be AI-assisted and what must remain a human decision.
A useful first outcome
The first delivery target is one complete review on fictional data: load a case, understand its assumptions, make a supported correction, see what changed and identify the evidence still missing. Another practitioner should be able to complete that task without the developer narrating every screen. This is a direction to agree together, not a promise to build an enterprise platform in one month.
Who would be a good fit
Strong Python and web-application experience, sound software-engineering judgement and an interest in product design. You should be comfortable with JavaScript or TypeScript, structured data, version control and automated tests. Experience shipping something used by others matters more than a particular framework. Industrial knowledge is welcome, but curiosity and willingness to learn the domain are essential.
Additional experience and working style
Experience with document workflows, auditable business applications, data engineering, manufacturing software or carefully evaluated AI features would be useful. You do not need to be expert in all of them. Responsible use of coding assistants is welcome; explaining and checking the resulting code is part of the work.
Why join at this stage
You would influence the first usable product, work directly with the founder and domain contributors, and help turn an open methodological foundation into a distinct commercial application. The product is early-stage: there is no claim of a finished enterprise service, proven industrial accuracy or measured customer savings.
Practical framework
This is a founding-team discussion. Responsibilities, commitment, working arrangements and start date will be agreed individually before work begins. The UK/France description concerns the venture’s development through Senoni; it is not a promise of a particular office location or remote-working arrangement.
Start the conversation
Write to Philippe Dagher with a short introduction, your availability and one project you are free to discuss. A CV, LinkedIn profile, portfolio or repository link is welcome but not required for the first conversation. No new implementation task or contribution to the public library is required to express interest. Do not send private employer or customer code.
Email : philippe.dagher@senoni.com
Subject : Axiocost — Founding Product Engineer
Explore the work
Axiocost and its two offers
Interactive fictional quotation example
Public working methods

Work arrangement
Yes