Available for senior technical leadership roles and select engagements
I turn tangled systems into things a team can actually build.
Hands-on technical and solution architect with 15+ years across product engineering, system integration and technical leadership. I am strongest where a problem is still ambiguous: understanding it, cutting it down to something buildable, and staying close enough to the implementation that the plan survives contact with production.
01 — Selected work
Case studies
Nine engagements with enough detail to be useful. Figures are the ones I can stand behind; where a number is not verifiable I say so rather than round it up.
-
2023 — 2024
ComplexCon Hong Kong
Technical architect
Designed the whole-system architecture behind a live event platform spanning identity, ticketing, commerce and customer data — then held it together on site under real load.
-
2025 — 2026
Libraro
Architect / Senior engineer
Diagnosed why a publishing platform fell over above ~20 visitors, directed the PostgreSQL and backend fixes, and built Python tooling to recover interrupted document workflows.
-
2025
Trajan Wealth
Technical architect / Technical lead
Owned architecture and led a ~10-person multidisciplinary team delivering a production AI assistant that answers questions against a client's own investment portfolio.
-
2024 — 2025
London Blockchain Conference
Technical architect
Architecture and integrations for two annual iterations of an event companion app — scheduling, meeting booking, messaging and a points-for-rewards loyalty loop.
-
2022 — 2023
RockWallet
Core iOS developer
Inherited a half-working clone of the open-source Breadwallet / BRD wallet with Android, C and Swift sources tangled together. Decoupled it, shipped it as Fabriik, then rebranded and extended it into RockWallet.
-
2025 — now
Blackjack Trainer
Sole technical lead & iOS engineer
Took over an operational iOS product and delivered a full production redesign, analytics, subscriptions and onboarding experiments. 24k MAU, 10k+ paid subscriptions.
-
2023
TradeWindow
Technical architect
Analysed a logistics monolith and defined a phased, parallel-run modernisation approach — including the honest finding that the job was far larger than estimated.
-
2020 — 2024
NKBM Mobile Bank
iOS architecture & technical enablement
Introduced Clean Architecture to a bank's mobile app, built the reference implementation, and taught the in-house developer to carry it forward. Returned for later delivery peaks.
-
Current
AI-assisted engineering workflows
Workflow designer & primary user
Human-reviewed workflows that connect Figma, Jira, Confluence and source code — daily change digests, task preparation and design-coverage gap analysis.
02 — Also
Other engagements
Product and engineering work that shaped the way I build, in reverse order.
-
AffilyStars
Technical / solution architect. The bridge between product design, client requests and the development team — turning intent into concrete technical direction. In development.
-
Iskalnik nepremičnin
A multi-stage research workflow over Slovenian public property data and the land registry, ending in a sortable HTML or Excel report. Cuts hours — sometimes days — off manual ownership research.
-
Ajeres
Designed and built a small Next.js and TypeScript application with a language-model capability wired in directly through Anthropic's SDK, on Firebase authentication and Firestore. A rapid hands-on prototype, not a production AI platform.
ajeres.si -
Commerce systems analysis
Mapped a fragmented landscape of Amazon, Microsoft Dynamics and several web shops, traced where inventory visibility was being lost, and delivered integration recommendations.
ekwb.com -
ComplexCon (v2)
Technical architect on an extension of the Hong Kong platform — authorisation boundaries, and Stripe holding everything payment-sensitive so no card data entered the platform. Its own ticket-selling platform had to reach production ahead of the rest, since tickets sell long before an event; early-bird sales ran through it. The project was cancelled before the remaining scope shipped.
-
Blarecast / BLARE
Lead developer on the iOS app for an artist-first music streaming and distribution platform, where artists self-release and rights holders receive instant split payments.
blaremusic.com -
E-Livestock Global
iOS developer on a cattle treatment and tracking solution — a livestock "digital passport" supporting farmers in Africa.
E-Livestock Global -
Molehill Mountain
iOS developer on Autistica's anxiety-support app, built by the UK autism research charity to help autistic people understand and manage anxiety.
autistica.org.uk -
MyMetraKey
iOS developer on the companion app for Metra's smart-locking technology, giving touch-less remote access to smart lockers.
App Store -
Fumis
iOS developer on the companion app for smart biomass and pellet-stove combustion controllers — remote monitoring and control of a physical heating system.
fumis.solutions -
BioEnergyUnit
iOS developer on a smart furnace monitoring and control application.
-
Pattern
iOS developer on a wellbeing application.
-
Capucinne
Shopify performance and technical SEO for a jewellery store, plus a custom purchase flow that broke past the platform's variant limit. The change materially increased revenue.
capucinne.com -
GlobaliD
Senior iOS developer. Split the application into modules to bring development build times down, and contributed to the product redesign.
global.id -
Chipolo
iOS developer on the first prototypes of Chipolo's Bluetooth item tracker — the keys, wallet and bag finder — in the run-up to the Kickstarter campaign that launched the product out of Trbovlje.
Kickstarter -
Beenius
Senior iOS developer. Introduced CI and code-review practice and restructured the app so each customer variant could be customised faster. GraphQL in the stack.
beenius.tv -
1Tap Receipts & Tax
iOS developer across two products: Swift 4 migration, feature work, analytics, and a serious dent in the accumulated backlog.
1tap.io -
ULU
Lead iOS developer and early employee on a connected-car product: journeys, driving events, diagnostics and fleet use cases, from an OBD device over eSIM. Objective-C, later rewritten in Swift.
ulu.io -
FlyKly Smart Wheel
Lead iOS developer on the companion app for a pedal-assist bicycle wheel — Bluetooth Low Energy protocol work with the hardware team, and support through the Kickstarter campaign.
Kickstarter -
OdoCost
Co-founder and lead iOS developer. Business-travel logging with two-way server sync and GPS tracking tuned hard against battery life.
-
Povio
iOS developer on Povio's original consumer product — a pull-based photo-sharing app where you ping a friend to take a photo, rather than pushing your own at them. It took the company into Y Combinator's Winter 2014 batch, before it pivoted into the software agency it is today.
Y Combinator -
Run&Roll
Co-founder and lead iOS developer on an endless-runner game: 40+ levels, an animation system, image caching and a custom level editor. Later the subject of my bachelor thesis.
Thesis -
Early mobile products
A run of consumer apps, games and prototypes alongside the founding work — H2O-Pal, Shakin Steve, avantBon, Rankberry, Megabon, LunchBox and Quick ordeR. Several were built with collaborators under the informal team name Mice3, which was never a company.
03 — History
Career
Fifteen years, told straight — including the two years I spent working on ski fields and in hospitality on the other side of the world.
-
2020 — present
Technical leadership & architecture-
RokIT d.o.o.
My own company, and the continuation of Rok Črešnik s.p. before it. I take on architecture, integrations, hands-on development, code review, releases and production troubleshooting, and provide technical and project leadership to multidisciplinary delivery teams. Engagements reach me by one of three routes: directly through RokIT, through EqualEyes d.o.o. supplying my work to its own clients, or onward to Teranode Ltd (formerly nChain Ltd) as end client. One career and one contracting structure — not several parallel jobs.
-
-
2017 — 2020
Senior iOS & product engineering-
Minimalvs d.o.o. / Capucinne
E-commerce performance, technical SEO and custom purchase-flow engineering for a DTC jewellery store on Shopify.
-
Kamino d.o.o.
Redesign, feature development and analytics. The GlobaliD application work ran during this engagement.
-
Beenius d.o.o.
Continuous integration, code review and a modular application structure so customer-specific variants could ship faster.
-
1Tap Ltd
Swift migration, dependency management, analytics and backlog reduction across 1Tap Receipts and 1Tap Tax.
-
-
2016 — 2020
Outdoor operations & guiding-
Expedition guiding — LifeTrek
After Kamino I had had enough of IT and set out to become an adventure tour guide. I spent a fortnight in the Georgian Caucasus leading back-to-back ski-touring groups as they rotated through, and guided a trekking tour in Kyrgyzstan that summer, both for the LifeTrek agency — taking responsibility for a group in remote terrain, where deciding to turn back is the call that matters and nobody else is going to make it. I flew home from Georgia and the lockdown began days later. The pandemic closed that door, and brought me back into software.
-
New Zealand & Canada
Guest reception, reservations and campsite allocation at Hack'n'Stay; lift operator at Porters Ski Field; night porter, maintenance and housekeeping at Rainforest Retreat; snowboard instructor at Kimberley Alpine Resort. Front-line operations work, in a second language, where the system that fails at 7am is a person waiting at a desk.
-
-
2014 — 2017
Connected mobility-
ULU b.v.
Sole iOS developer and technical owner of the driver-facing app for a connected-car and fleet product. Contributed to API design and reusable visual components, and took part in StartupBootcamp HighTechXL in Eindhoven.
-
-
2012 — 2014
Games, mobile products & early startups-
Co-founder & lead iOS developer
End-to-end ownership across a game with its own level editor, a business-travel tracker with two-way sync, and a Bluetooth-connected bicycle wheel. Alongside them a run of early consumer apps and prototypes — H2O-Pal, Shakin Steve, avantBon, Rankberry, Megabon and Quick Order — several built with collaborators under the informal team name Mice3, which was never a company.
-
-
2010 — 2012
Enterprise & web beginnings-
Adacta d.o.o.
Support department for international clients, producing reports and additional views in a Microsoft Dynamics AX / X++ environment. My first exposure to business systems that people depend on to get paid.
-
spletnaPOSTAJA d.o.o.
PHP/MySQL and custom client projects.
-
04 — How I work
Capabilities
- Solution architecture through implementation. I do not hand over a diagram and leave. The plan is only good if it survives the first sprint.
- System integration. REST, webhooks, authentication and third-party platforms — usually several of them, usually disagreeing with their own documentation.
- Technical-debt analysis and phased modernisation. Extract one responsibility, run it in parallel, compare outputs, then move production traffic.
- Performance and data access. PostgreSQL and SQL profiling, query and access-pattern redesign, load and performance testing against a modelled scenario.
- Technical leadership for teams of up to ~10 and cross-functional delivery groups of ~20 — delivery direction and accountability rather than formal line management. Technical interviews, task assessment and one-to-one coaching.
- Build-vs-buy and vendor selection. Feature, risk and cost comparisons that a non-technical stakeholder can actually decide from.
- AI-assisted engineering. Practical everyday workflows with independent review stages, never autonomous approval.
Languages & data
Python · SQL / PostgreSQL · TypeScript & Node.js · Swift · Go · X++ (historical)
Integration & cloud
AWS · AWS Cognito · Auth0 · MuleSoft · Salesforce · Shopify · Stripe · RevenueCat · REST & webhooks
Delivery
Git & code review · CI/CD · GitHub Actions · Docker · Jira · Confluence · Figma · Firebase Analytics · A/B testing
Business platforms
Microsoft Dynamics AX · Appian · Wagtail
Education & certification
University of Ljubljana, Faculty of Computer and Information Science — University Diploma
in Computer Science and Informatics, pre-Bologna programme, 2013.
Appian Certified Associate Developer, June 2025.
Ran an introductory Python workshop at Gimnazija Slovenj Gradec.
Languages
Slovenian (native) · English (fluent) · German and Croatian (conversational)
05 — Contact
Send me the messy version of the problem.
The engagements I enjoy most start with a system nobody fully understands any more, or a requirement nobody has yet written down properly. Whether that is a role or a contract, I am happy to talk it through.
- rok@cresnik.com
- linkedin.com/in/rcresnik
- CV
- Read online · Download PDF
- Based in
- Slovenia — working remotely with teams across Europe, the UK and the US
- Company
- RokIT d.o.o.