iOS Engineer · Mobile Architect · Łódź, PL

Guillermo R. Delgado

14+ Years Shipping Digital Identity 51.76° N, 19.46° E

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Years Experience

Apps Shipped

Companies

Open-Source Repos

01 Driver Dossier

The Profile

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.

Off the screen you'll find me chasing splits on a run and Sunday-morning race starts — the same instinct for precision, pace and clean lines that I bring to every build.

02 Career Laps

The Grid

Fifteen years on track, from large-format printers to nation-scale digital identity.

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.

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.

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.

Senior iOS Software Engineer

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

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

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.

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 The Garage

Selected Builds

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

BUILD // 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

BUILD // 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

BUILD // 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

BUILD // 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

BUILD // 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

BUILD // 06

b64img↗

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

Open SourceUtility

◈Digital Identity

BUILD // 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

BUILD // 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

BUILD // 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

BUILD // 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

BUILD // 11

TomTom MyDrive↗

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

iOSNavigation

BUILD // 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

BUILD // 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

BUILD // 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

BUILD // 15

iULE

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

iOSEducation

BUILD // 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

BUILD // 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

BUILD // 18

Blizzability

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

iOSFramework

04 Spec Sheet

Under the Hood

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 Lights Out

Let's build
something fast.

Have a product to ship, an identity problem to crack, or just want to talk Swift, Godot and running splits? The line's open.

gelemias@gmail.com LinkedIn GitHub