I'm Guillaume Rufenacht. Through iBuildYourApp, my consulting practice, I help small and mid-sized businesses win more clients: websites that convert, SEO and paid search, revenue attribution, and lead handling on autopilot.
Years in product & growth
Products built 0→1
Users onboarded
Clicks for a client (SEO/SEA)
01 / Services
Four ways I turn your website and marketing into a system that brings in leads, and proves which channels actually pay off.
I rebuild your website around one job: turning visitors into leads. Clear positioning, fast pages, and an obvious path to the action you want them to take.
Get found by people already looking for what you sell. SEO that compounds over time, and paid search that brings qualified traffic now.
Stop guessing where your clients come from. I connect traffic, leads, and closed revenue so you know which channels actually pay off.
Stop losing leads to slow, manual follow-up. I automate lead handling and the repetitive day-to-day so nothing slips through the cracks.
Two ways to work together
A defined scope with a clear outcome: a website redesign, an attribution setup, or an automation build. Fixed timeline, fixed price.
An ongoing partnership for compounding results: SEO, ads, experiments, and continuous improvements to your funnel. Month to month.
02 / About
I've spent seven years taking products from zero to one across fintech and crypto, owning the whole loop: discovery, design, build, pricing, and growth. iBuildYourApp brings that same end-to-end approach to small and mid-sized businesses that want more clients.
I'm technical enough to build what I propose (websites, automations, data pipelines, AI agents), so you work with one person who is accountable for the outcome, not a chain of handoffs. And I'm data-first: decisions come from conversion, cost, and channel performance rather than opinion.
When I'm not on client work, I'm building Geonimo, a B2B SaaS for brand visibility in AI search, which keeps me on the front line of how customers actually find businesses today.
Based in
Lisbon, Portugal
Work rights
French / Swiss (EU)
Currently
Founder at Geonimo
Education
ESCE · MSc International Finance
Languages
03 / Proof
Client engagements and products I've built from zero, each taken to real users and measurable outcomes.
A B2B SaaS that measures and improves how brands show up in AI search (ChatGPT, Perplexity, and Google AI Overviews). Bootstrapped from zero, owning the full loop: customer discovery, MVP scoping, pricing, and weekly iteration driven by activation and churn data.
+150%
Growth · last 6 mo
0→1
Built solo
Growth · last 6 months
A fintech workflow that turns mortgage documentation into bank-ready files 3× faster. Borrowers upload through a private, auto-localized link (no signup), brokers validate in one click, and banks receive complete, organized packages, all EU-hosted and GDPR-compliant for cross-border deals across France and Portugal.
3×
Faster files
+30%
Loans closed
A B2B intelligence platform that identifies the companies visiting your website, scores buyer intent, and ties every lead back to its marketing channel, so teams can finally quantify revenue per source. Identifies 25-35% of B2B traffic from a single script, with native HubSpot, Salesforce, and Pipedrive sync.
25-35%
B2B traffic ID'd
3×
Higher response
Payment rails for AI agents
Payment infrastructure that lets AI agents transact over HTTP in stablecoins. Programmable, machine-native payments for the emerging agent economy.
Synthetic exchange on Telegram
A retail leveraged DEX built as a synthetic exchange in Rust, delivering leveraged exposure through Telegram plus an on-chain investment system on Uniswap. Defined product scope and led 4 engineers from MVP to production.
$60M
Trading volume
400+
Users
Institutional crypto exchange
Product Owner for XBTO's institutional crypto exchange. Ran discovery, prioritization, and feature delivery with engineering in a regulated, multi-stakeholder environment.
04 / Background
Lisbon
Paris
Lisbon
Lisbon
Paris
05 / Writing