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iOS Engineer · Mobile Architect · Łódź, PL

Guillermo
Rodríguez Delgado

Get in touch LinkedIn GitHub
0+Years
0+Apps shipped
0Companies
0Open-source repos
01 Profile

The short version

I've spent 14+ years building mobile software, and these days I lead iOS at IDEMIA, designing the architecture behind government-grade digital identity — wallets, verifiable credentials and ISO 18013 mDoc flows, where security, performance and long-term maintainability aren't features but the product itself.

After hours I keep the craft playful: a pixel-art virtual pet that teaches kids math in SwiftUI, two Godot games — an isometric defense game and a remake of a 2015 title whose source was lost — an open-source leaderboard backend on Cloudflare Workers meant to hold every one of their scoreboards, and tooling for testing identity-wallet interoperability. Whatever the project, the through-line is the same — a strong focus on UI and custom-built components, choosing the right approach for each specific need rather than the fashionable one.

Away from the screen I run — long, early and quiet. The same patience for pace, and for getting the small things right, goes into everything I build.

02 Path

Where I've built

Fifteen years of building, from large-format printers to nation-scale digital identity.

01

Mobile Architect, iOS

IDEMIA · Łódź, Poland 05/2023 — Present

Designing technical architecture and owning the hard engineering problems for large-scale digital-identity platforms.

  • Own architecture decisions on non-functional aspects: performance, high availability, resiliency and security.
  • Translate functional and business requirements into the right architecture and technologies.
  • Enforce architectural and technological consistency across every platform component.
  • Drive code-review processes to guarantee the best software quality.
02

Senior Software Developer, iOS

IDEMIA · Łódź, Poland 05/2018 — 05/2023

Delivered quality software within the timeframe committed by the team.

  • Shipped features with Product Owners and Functional Analysts, backed by tests and thorough review.
  • Implemented and improved non-functional items: high availability, performance and platform monitoring.
  • Contributed to common libraries used across products while keeping technical debt low.
02 — Path, continued
03

iOS Developer & Consultant

Freelance · Remote 2011 — 2018

Worked with international organizations and individuals as a freelance iOS developer and consultant, with a track record of on-time, on-budget delivery.

04

Senior iOS Software Engineer

Mobica · Łódź, Poland 12/2014 — 04/2018

Engineering and consultancy services spanning the breadth of software design, engineering and testing.

05

iOS Software Engineer

Rule Financial · Łódź, Poland 11/2013 — 11/2014

Technical consulting and IT services for investment banks, asset and wealth management, and related financial institutions.

06

Software Engineer

Hewlett-Packard · León, Spain 04/2011 — 10/2013

Built the Windows desktop application for large-format printers, focused on UI, using Windows Presentation Foundation.

03 Work

Selected work

Products shipped, tools open-sourced, games built for the joy of it.

Sumo key art — a mystery pack bursting open to reveal the pixel-art mascot
01

Sumo↗

Virtual-pet learning game, live on the App Store. A child opens a mystery pack and cares for its mascot by completing short bursts of multiple-choice math, with invisibly adaptive difficulty. Local-only, no accounts, no ads — cheerful pixel-art for ages 4–12.

iOSSwiftUIEducationKids
Jumpy Chewie key art — the orange gum blob clinging inside a monster's open mouth, ringed by teeth
02

Jumpy Chewie (Remake)

Godot 4 remake of my 2015 SpriteKit game, rebuilt from surviving marketing art after the original source was lost. You are a blob of gum clinging to the rim of a monster's mouth: gravity drags you down while teeth ride the rim trying to chew you. Portrait, one thumb, endless — score is jumps survived. No physics engine anywhere: the rim is a one-dimensional looping track traced from the artwork's alpha channel.

GodotGame DeviOSAndroid
Turn Siege key art — an isometric gas station on a lit platform, surrounded on all four fronts by advancing zombies
03

Turn Siege

Fast-loading, bite-sized isometric defense game built with Godot 4, coming to iOS and Android. Your gas station sits on a four-front battlefield but you can only cover two fronts at once — swipe to spin the view and bring your guns to bear. Fully procedural graphics and daily streak rewards.

GodotGame DeviOSAndroid
</>Open Source
04

Leaderboard Platform↗

Open-source leaderboard backend on Cloudflare Workers and D1 — one scoreboard for all my games. Runs start from a server-issued, one-shot session bound to a game, player and ruleset, and submissions carry an input trace that an optional per-ruleset simulator replays before a score is allowed to count. Daily, weekly and all-time boards, a public game catalogue and rate-limited read feeds.

Open SourceTypeScriptCloudflare WorkersBackend
</>Open Source
05

mdoc-verifier↗

Open-source FastAPI demo verifier for ISO 18013 web-retrieval flows — generates mdoc:// QR deep links, derives session keys and exchanges encrypted CBOR DeviceRequests to test wallet interoperability for PhotoID-style requests.

Open SourcePythonISO 18013Identity
</>Open Source
06

b64img↗

Simple, no-frills base64 image decoder — paste an encoded string, get your image back.

Open SourceUtility
03 — Work, continued
◈Digital Identity
07

ID Wallet↗

Secure digital-identity wallet for managing verifiable credentials and identity documents — identity proofing through document scanning, NFC passport/ID verification and biometric authentication, with consent-driven attribute sharing.

iOSIdentityNFCBiometrics
◈Digital Identity
08

Mobile ID↗

A contactless, highly secure, government-approved personal credential living on the user's smartphone. Multi-modular components distributed as an SDK for integrators or as a theme-able application.

iOSSDKSecurity
RDGliderViewController — draggable glider control demo
09

RDGliderViewController↗

Open-source responsive control, written in both Swift and Objective-C, for a draggable view controller gliding over another view controller.

Open SourceSwiftObjective-C
T-Mobile Tuesdays app screen
10

T-Mobile Tuesdays↗

Highly acclaimed US app offering vouchers and discounts to users — reached the Top 50 in the App Store several times.

iOSConsumer
TomTom MyDrive route-planning screen
11

TomTom MyDrive↗

TomTom's client for the MyDrive service — plan a route from your device, then read it on your navigation device.

iOSNavigation
Jumpy Chewie game screen
12

Jumpy Chewie (2015)

The original: a universal game for iOS built with SpriteKit, featuring Game Center connectivity, push notifications and in-app purchases. Its source was lost — hence the remake above.

SpriteKitGame Center
03 — Work, continued
UrbanForms mural-map screen
13

UrbanForms

Companion app for the yearly urban-art festival in Łódź, Poland — navigate every mural painted in the city, get to know the art and stay up to date with the event.

iOSMapsUrban Art
MigawKarta transport app screen
14

MigawKarta

Tracking for all public transport in Łódź, including management of the local "Migawka" travel card — expiration alerts, news, timetable changes and payment history.

iOSTransport
iULE university app screen
15

iULE

App for the University of León integrating dashboards, lists and account screens so students and professors can better manage their lessons.

iOSEducation
Deutsche Bank Summit iPad app welcome screen
16

Deutsche Bank Summit

iPad ad-hoc app helping executives manage their relationships with delegates and attendees at the Summit conference.

iPadEnterprise
HP Designjet print-preview utility screen
17

HP ePrint & Share

HP ePrint service for printing documents via tablets, smartphones, laptops and printers, alongside desktop utilities for large-format HP printers.

WPFC#
⬡Framework
18

Blizzability

Framework for apps dynamically driven from a CMS — personalizing module loads and optimizing offline data handling.

iOSFramework
04 Toolkit

What I work with

Mobile & Languages

SwiftSwiftUIObjective-CCocoa TouchPythonC#C++TypeScriptJavaScriptGDScript

Backend & Platform

Cloudflare WorkersD1 / SQLiteREST APIsFastAPIRate LimitingServer-Side Validation

Digital Identity & Security

ISO/IEC 18013 (mDL / mDoc)Verifiable CredentialsNFC Document VerificationBiometric AuthenticationCBORApplied CryptographySecure Architecture

Engineering Practices

Software ArchitecturePerformance & High AvailabilityUnit TestingTDD / BDDIntegration TestingCode ReviewAgile / ScrumGit

Games & Design

Godot 4SpriteKitProcedural GraphicsDesign SystemsCustom UI ComponentsUX DesignPixel ArtPhotoshop / Illustrator

Education

BEng, Computer Science
Universidad de León · 2006 – 2011

BEng, Computer Science
Kaunas University of Technology · 2008 – 2009

Languages

Spanish — Advanced
English — Advanced
Polish — Intermediate

Awards

Value Based Award
Fgulem III Prototypes Contest (2012)

05 Contact

Let's build
something good.

Have a product to ship, an identity problem to crack, or just want to talk Swift, Godot or long runs? My inbox is open.

gelemias@gmail.com LinkedIn GitHub