I design and buildwebsites, apps andcustom software.

Bring me a new idea, a difficult existing system or a project that has stalled. I take it from the first decision through design, development and launch for businesses in Europe and the Americas.

Tell me about your project

Selected work

March 2026 · ongoingAppointment booking platform August 2026 · ongoingCommerce integration platform April 2026 · ongoingMobile health and activity app July 2026 · ongoingMarketing website and lead delivery May 2026 · ongoingData analysis and decision support

March 2026 · ongoing

Appointment booking platform

A multi-tenant platform where customers book appointments and each service business manages its own locations, staff and schedule.

What I did

I built the customer booking journey and the tools used to run it, including availability, location rules, customer records, staff workflows, confirmations and live updates.

What was delivered

Customers get a simple path from choosing a location to a confirmed appointment. Each tenant gets one place to manage the day-to-day work behind it.

Selected technology

React
TypeScript
Cloudflare Workers
D1
Realtime events

August 2026 · ongoing

Commerce integration platform

A complete API for moving the required catalog, pricing and inventory data from an ERP into a commerce platform.

What I did

I designed and built the API, access controls, tenant administration and multi-step queue processing. Every step can run again safely and transforms the ERP data into the format the commerce platform needs.

What was delivered

Teams can follow every event through the system, see where it failed and replay it without duplicating work that already succeeded.

Selected technology

TanStack Start
TypeScript
Cloudflare Workers
D1
OpenAPI

April 2026 · ongoing

Mobile health and activity app

An iOS app that imports activity data from HealthKit, with backend services and admin tools for understanding what happened during each sync.

What I did

I work on both the app and the backend, from the HealthKit screens and sync logic on the phone to the APIs, processing jobs and activity explorer on the server.

What was delivered

The sync runs across several processes, but it can be followed as one journey. The team can tell whether a problem happened on the phone, during upload or while the server was processing the data.

Selected technology

iOS
HealthKit
React
TypeScript
Cloudflare Workers

July 2026 · ongoing

Marketing website and lead delivery

Fast websites and landing pages built to turn campaign traffic into leads without making the form or the message harder than it needs to be.

What I did

I build the pages, simplify the forms and connect each lead to the right destination. I also set up the tracking needed to understand which campaigns and pages lead to real enquiries.

What was delivered

The tracking is delivered through the site's own subfolder instead of depending on browser-side tags. Combined with server-side Google Tag Manager and first-party cookies, it is less likely to be discarded by ad blockers or browser privacy controls, so campaign attribution stays connected across repeat visits.

Selected technology

React
TypeScript
Cloudflare
Google Tag Manager
First-party tracking

May 2026 · ongoing

Data analysis and decision support

Data analysis for businesses that need a sound basis for deciding what to change and what to leave alone.

What I did

I first check whether the data can be trusted, then study the question from several angles. I combine those findings with years of business and conversion work, including how people read, hesitate and make decisions.

What was delivered

The recommendation is never based on one chart or a gut feeling. I show the data, the human behavior behind it and the reasoning that connects both to the business decision.

Selected technology

SQL
Spreadsheets
Dashboards
Business analysis

May 2026 · ongoing

Integration monitoring and recovery

Integrations that keep leads and operational records moving between queues, CRM systems and spreadsheets.

What I did

I find out why records stopped moving, keep a useful history of each incident and add alerts that say when an outside service fails and when it starts working again.

What was delivered

The people running the business can see what was delayed, what recovered and which records still need attention.

Selected technology

Cloudflare Workers
Queues
CRM integrations
Google Sheets
Slack

What I can take on

Some projects begin with a blank page. Others begin with a system that already exists and needs to become easier to use, safer to operate or ready for its next stage.

Websites and landing pages01
Mobile applications02
Middleware and integrations03
Custom platforms and internal systems04
Data analysis and consulting05
Conversion rate optimization06
Email deliverability07
Performance and scalability08
Production investigation and recovery09

Conversion work starts before the button.

I look at the page as a visitor would. Is the offer clear? What creates doubt? What makes the next step feel like too much work? A different button color rarely answers those questions.

I compare behavior data with what the business knows about its customers, then use my experience to decide what the evidence means. If a test can settle a real question, I run it. If the problem is already clear, I fix it and measure the result.

Email deliverability is a company-wide system.

I check every part of the company's email setup that can affect whether a message reaches the inbox. That includes domains, sending platforms, authentication, DNS, reputation, sending patterns, bounces, complaints and spam reports.

I explain what needs to change and make the updates where I have access. For the parts owned by the client's team or another vendor, I work with them until the setup is corrected.

I record the starting point and monitor what changes afterward. The before-and-after data shows what improved delivery, where problems remain and what to fix next.

25+ years of building digital products that have to work.

I am Lars Houmark, an independent developer and consultant. I have spent more than 25 years working with digital products and the businesses behind them, so I can discuss the commercial decision as well as the code or interface.

I take responsibility for the work and plan to deliver on time. I will also say so when I think an idea, requirement or technical choice can be better.

Performance and scale are considered from the start. For websites and landing pages, that means making sensible choices about speed, technical quality, business needs and budget.

I work fluently in English, Danish and Spanish.

Have a project in mind?

Send a short note about what you are building, what already exists and where you need help. I will reply directly.

lars@houmark.com