# Extra.dev

> Software built for the present, engineered for the future. A software engineering team you can drop into a serious problem. Engineers who have shipped production at scale build your web, mobile, AI/ML, embedded and desktop software, fast and built to hold up. Hyperice backend taken over one month from launch and shipped on time.

Extra.dev is a software engineering team of 16 engineers based in Ljubljana, Slovenia, working across the EU, UK and US. Every engineer has shipped production at scale and owned outcomes from architecture through launch. We build web platforms, mobile and desktop applications, AI systems, embedded and IoT software, and the DevOps and QA around them. Engagements run as paid workshops, embedded individual specialists (engineering, QA, design, product, DevOps), dedicated teams, or fixed-scope projects. The work is often mission-critical: defence audit trails for Rheinmetall, radiation-therapy control software at Cosylab, government healthcare with no public cloud for Ropca, MiFID II-regulated fintech. We are GDPR-native and build to a client’s regulatory framework; we hold no SOC 2 or ISO 27001 certification of our own and say so up front.

Clients include: Hyperice, Blissbook, Mikrocop, IMT Analytics, PrizePicks, Cosylab, Apillon, Megabon, Naval Architect, JonatanMars, SRC, Avenir Global, EnergijaSOL, PunkPadel, Magistrat International, Rheinmetall, FreedomChat, Seavizor, ORS, MountainGreen, BOmind, Green Line Arb.

Contact: hello@extra.dev · Replies within one working day · CET / CEST · Based in Ljubljana, Slovenia
Full text of this site in one file: https://extra.dev/llms-full.txt
Every page below is also served as markdown at the same URL with `.md` appended,
e.g. https://extra.dev/work/hyperice.md, if you want one page rather than all of them.

## Services

- [Project Management](https://extra.dev/services/project-management): Planning, coordination, and delivery management.
- [Design](https://extra.dev/services/design): Product design, UX, UI, and design systems.
- [Web](https://extra.dev/services/web): Front-end, back-end, and full-stack web development.
- [Mobile](https://extra.dev/services/mobile): Native iOS and Android, and cross-platform apps.
- [Desktop](https://extra.dev/services/desktop): Native and cross-platform apps for macOS, Windows, and Linux.
- [AI / ML](https://extra.dev/services/ai-ml): Generative AI and agents, computer vision, and predictive models.
- [Embedded & IoT](https://extra.dev/services/embedded-iot): Firmware, on-device control, and fleet management.
- [DevOps](https://extra.dev/services/devops): CI/CD, cloud infrastructure, observability, and security.
- [QA](https://extra.dev/services/qa): Automated and manual testing, load, and security.

## How to engage us

- [Workshops](https://extra.dev/engagement/workshops): Focused discovery, technical reviews and planning for the next decision.
- [Specialists](https://extra.dev/engagement/specialists): Specialists embedded in your team, working under your direction.
- [Teams](https://extra.dev/engagement/teams): A dedicated team led by us to build and improve your software.
- [Projects](https://extra.dev/engagement/projects): Defined work delivered for an agreed fixed price.

## Selected work

- [Hyperice](https://extra.dev/work/hyperice): Backend rewrite for the HyperSmart app, four weeks before launch. Four weeks before HyperSmart launched, we took over a backend that was slow, crash-prone and not built to scale. We rewrote it, moved the earlier app’s users across without downtime or sign-outs, and launched on the original date at 25,000+ concurrent users. We then built five health integrations and AI longevity scoring.
- [Blissbook](https://extra.dev/work/blissbook): AI features and core product development for HR policies. Blissbook is an HR policy platform serving 500,000+ people. From a 2025 notification workshop, we joined its product team, building core features and its AI: an assistant that respects access rules down to each policy section, and AI Check, which reviews policies against each customer’s own guidelines.
- [Mikrocop](https://extra.dev/work/mikrocop): Building secure automation for document workflows. Four of our engineers worked on Mikrocop’s InDoc EDGE from June 2024 to September 2026. We built its Scripting Sandbox end to end, delivered three modules and then joined the core team. Signing became 65% faster, script throughput doubled, and the releases we worked on shipped 30% more feature tickets, a record.
- [IMT Analytics](https://extra.dev/work): Mobile software connecting medical test instruments. Swiss precision instruments for testing ventilators and anaesthesia machines. We took ownership of the FlowMeter App and scaled it across the product line: seven device models, Bluetooth byte streams decoded into live readings, and a full history on the phone with no signal needed.
- [PrizePicks](https://extra.dev/work): Architecture and development for The Esports Lab. The esports product inside a daily-fantasy-sports platform, where traffic arrives in a spike the moment a match starts and every number on screen has to be current. We led architecture, development, testing and scaling end to end.
- [Cosylab](https://extra.dev/work): Application development for particle therapy treatment planning. We built both halves of PlanOne from inside Cosylab’s own product team: the .NET services underneath, and the application a medical physicist plans in. V1.0 is FDA 510(k) cleared. Separately, one engineer integrated systems for one of the largest private radiation-therapy clinics in the US.
- [Apillon](https://extra.dev/work): Storage, hosting and developer tools for Web3. Built out the Storage, Hosting and Infrastructure modules alongside their team, then took over the dashboard front end when internal resources were cut. Continuous deployment to IPFS, one-click NFT campaigns and metered RPC endpoints: 1M+ files uploaded, 1,000+ production websites deployed.
- [Megabon](https://extra.dev/work): Backend modernisation and booking tools for travel offers. Took over the live marketplace from a struggling previous team, rewrote the entire back end off Rails and built the admin dashboard the business runs on.
- [Naval Architect](https://extra.dev/work): Engineering software for ship design and visualisation. One engineer, embedded for three years, across three modules: Angular for the visualisation, NestJS for authentication and the GraphQL data layer, and C++ for the geometric computations. The hard part was the synchronisation between design tools that each hold a different version of the same ship.
- [JonatanMars](https://extra.dev/work): Investment app and backend for portfolio management. An ATVP-licensed firm managing client portfolios under MiFID II had proved the demand on an off-the-shelf web platform and wanted its own app. A workshop reviewed what existed, then the app and the backend were built from the ground up, with the test depth the regulation demands. AI-augmented delivery came in around 25% faster.
- [SRC](https://extra.dev/work): Clinical web application for Slovenia’s emergency medical services. Embedded with Slovenia’s leading systems integrator on the Ministry of Health build. We built the doctor-facing web application and the SOAP integration layer into the government eHealth services behind prescriptions, referrals and patient records.
- [Avenir Global](https://extra.dev/work): Desktop applications and AI for a communications group. An Electron application over Maconomy, rolled out across the group, that turned into ten-plus projects since: client-facing web work, an AI notetaker, AI web search and a document-extraction pipeline.
- [EnergijaSOL](https://extra.dev/work): Battery control and solar energy management software. Another team’s proof of concept was not production-ready. We reviewed it, proposed a rewrite and priced it, then built the platform: the C++ that gets readings off the battery hardware, and the app an operator runs the site from.
- [PunkPadel](https://extra.dev/work): Court booking, payments and access control for padel venues. Took over another team’s PHP platform, moved it off a host that capped it at 500 database connections an hour, and rebuilt the payment path underneath it. Since then: 4× the bookings, and a third venue the client opened without a developer.
- [Magistrat International](https://extra.dev/work): Wholesale ecommerce and the Emporium shopping app. A scoping workshop, with wireframes, designs and estimates, won the wholesale build against alternatives. It runs on Shopify: a B2B storefront for the arm that resells in bulk to retailers across the region. The second project is the group’s department store app, in Flutter.
- [Rheinmetall](https://extra.dev/work): Product catalogue and configuration platform for defence. Built it end to end for one of Europe’s largest defence companies, from the Angular front end to Terraform on AWS. Product managers define their own properties and validation rules without waiting for a release.
- [FreedomChat](https://extra.dev/work): Private messaging with end-to-end encryption. The entire backend for a zero-knowledge messaging platform, built after a previous team could not deliver. Shipped on schedule, audited by Seald, past 20,000 downloads in the US alone.
- [Seavizor](https://extra.dev/work): Web and mobile tools for shipbuilding project management. Worked across the Django backend, the Angular front end and the Flutter app, and fixed the offline support the crews on the jobsite depend on.
- [ORS](https://extra.dev/work): Travel booking websites managed through a shared platform. Travel agencies and resellers, each with its own domain, languages, branding and payment account, all served from one Remix codebase against ORS’s booking API. Search, offer verification and checkout included, and delivery about 30% faster through AI-augmented development.
- [MountainGreen](https://extra.dev/work): Affiliate commerce platform with automated commissions. Research, personas, flows, designs and then the build: a multi-level affiliate platform for hundreds of thousands of participants. MVP in 11 weeks, and a commission engine that has to be exactly right.
- [BOmind](https://extra.dev/work/bomind): Mental health tracking and online therapy in one app. Built end to end from the initial idea: defining the scope, shaping the product, designing the experience, then building and continuing to develop it. Live since July 2024, with 4,500+ users in the first six months and 116,000+ entries logged.
- [Green Line Arb](https://extra.dev/work): Mobile tools for UK arborists and tree surgeons. Took the app over mid-life from another team and stabilised it. 20,000+ registered arborists, 9,400+ drop points mapped, 164,000+ map searches a quarter.

## Company

- [Work](https://extra.dev/work): Every case study in one index.
- [Contact](https://extra.dev/lets-talk): Book a 30 minutes intro call with an engineer, or send the project in writing.

## Frequently asked

- **Who will we actually be working with?** You’ll work with engineers who’ve built and scaled production systems in the real world, and who act like owners, accountable for the result, not just the task in front of them. They combine deep technical range with genuine commercial sense, building toward what your business actually needs. They keep communication clear, raise risks early, and operate with minimal oversight.
- **Will the same team stay on our project from start to finish?** Yes. The team assigned to your project remains dedicated to it throughout, we don’t reassign people to other clients. In the rare event a team member must transition off, their successor is brought on in advance and works alongside them until fully up to speed, ensuring a clean knowledge transfer and uninterrupted delivery. The ramp-up is absorbed by us, at no cost to you.
- **What if we’re not sure exactly what we need yet?** That’s common, it’s exactly what our workshops are for. We figure it out together: the real problem, the constraints, and what’s actually worth building. From there we turn it into a plan, timeline, cost, and approach, that you sign off on before any work starts. If you already know what you need, we skip ahead to that plan.
- **How does pricing work, and how do we stay on top of the budget?** Scope, cost, and terms are agreed in writing before any work begins, nothing hidden. Throughout, you have full oversight: regular reporting on progress and spend, so the budget is never in question.
- **How do you handle security and data protection?** We’ve delivered for regulated finance, medical software, and enterprises with their own strict security standards, so building under real requirements is familiar ground. As an EU-based team, GDPR is a given. When a project answers to a specific framework, we work to it, whether that’s SOC 2, ISO 27001, HIPAA, or an internal standard of your own.
- **How do we work together across time zones?** We have run distributed engagements across the EU and US for years. We adapt to how your team operates, hold real overlap on your hours, and keep you close to progress so you are never guessing. When a project benefits from meeting in person, we come to you. Distance has never been what decides a project. The people and the execution are.