Software engineering for startups and product teams

I design and build mobile, web and backend systems and see them through to production. Twenty years of it, most in the UK. Based near Lisbon, working with clients across Europe.

Previously at deskbird, Worldpay, Trainline, Nokia and others.

Currently available for new engagements.

Get in touch

Services

Engineering

I join your team as a senior engineer and ship features end to end: mobile, web, backend and infrastructure. I typically work two to three days a week, remote, on a B2B contract. When the engagement ends you keep the code, the infrastructure and the documentation, and your team carries on without a gap.

Fractional CTO

Technical leadership for companies that aren’t ready for a full-time CTO. I take on the architecture, technical hiring, code review, vendor choices and the technical side of investor conversations, one to three days a week on a monthly retainer. Working sessions with your engineers are part of it.

Fixed-scope delivery

I quote a fixed price and a delivery date for a defined piece of work, and take the whole thing: design, build, deploy and hand over. It suits a first version, a rebuild, or a project your team doesn’t have the capacity to start.

Projects

Built and run by Rather Active, alongside client engagements.

evvnly

evvnly

evvnly splits group expenses and settles everyone with the fewest transfers. Friends join with a link, no install and no account. Groups can mix currencies at live rates, set up recurring bills, scan receipts and set budgets that warn before the money runs out. I built it in Flutter for iOS, Android and the web, with Node and Firebase behind it, between May and September 2026.

Rather Useful

Rather Useful

Rather Useful is a growing set of small web tools where each one is a single page that loads from the edge and does one thing. So far it has password and UUID generators, a JSON formatter, world time, a countdown and a date calculator. It’s built around a central registry, so adding a tool means one page and one line of metadata. It runs on SvelteKit and Tailwind on Cloudflare Pages.

Rave Ops

Rave Ops

Rave Ops is the build and hosting platform my own projects run on. It gives every project Kubernetes with Knative, a private code repository and container registry, CI/CD pipelines, TLS certificates that renew themselves, and backups that have been tested by restoring from them. A new project gets all of it from one form, in about a minute.

About me

Slawomir Biegluk

Slawomir Biegluk

Founder & Principal Engineer

I was a staff engineer at deskbird, where I set the architecture and engineering standards and coached the team. Before that I spent four years at Worldpay, as a senior solutions architect and a principal software engineer, working across its payment gateways and leading the design of a payments forecasting and alerting platform. Where I have worked has the longer version.

Now I ship whole products, from the mobile and web apps down to the backend and the infrastructure underneath, and I make the product calls as well, including what to build and what to leave out. I work with a few clients at a time, so each one gets someone who knows their system well enough to make decisions. For design work and bigger projects I bring in people I’ve worked with before.

I’m based in Carcavelos, Portugal.

Collaborators

People I bring in when a project needs them.

Greta Vainoraite

Greta Vainoraite

UI, UX and graphic design

Get in touch

Contact details

Send me a few lines about what you’re building and where it’s stuck, and I’ll tell you whether I’m the right person for it.

Carcavelos, Portugal