Kimi.
Ezequiel (Kimi) Aceto

About

About me

I am a builder of mobile platforms, developer experience, and experimentation for banking apps used by 20M+ people. I write about the craft of shipping software.

I'm Ezequiel Aceto, most people call me Kimi. I'm a Principal Software Engineer at Openbank (Santander Group) in Madrid, where I lead the experimentation domain, analytics, feature flagging, RUM, and session replay, and define the architecture for Server-Driven UI and Server-Defined Events across web, iOS, and Android.

Over 15+ years I've worked across the whole stack, from embedded firmware to enterprise SDKs serving 20M+ users in 7+ countries. I care most about platform engineering and developer experience: turning architecture decisions into measurable impact, like cutting analytics costs by 70%, shaving 45% off CI/CD times, and driving org-wide adoption of modular SDKs.

I'm an AWS Certified Solutions Architect and spent 8+ years as an Adjunct Professor at the Universidad de Buenos Aires, teaching embedded systems and microcontroller programming. I also build open source: OpenCoreLocation, a Rust multiplatform template, and QRDefender among them. I also write here about architecture, mobile, and the craft of shipping software.

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Career

Experience

  1. Dec 2025 — Present

    Principal Software Engineer · Openbank (Santander Group)

    Lead the experimentation domain — analytics, feature flagging, RUM, and session replay — across web, iOS, and Android for Openbank and Santander Mexico. Architecting Server-Driven UI and Server-Defined Events, and drove a GTM server-side migration that cut analytics costs by 70%.

  2. Jul 2022 — Dec 2025

    Senior Software Architect · Mobile · Openbank (Santander Group)

    Headed the Developer Advocates and Technical Documentation teams and sat on the iOS Architecture Team. Built a modular SDK ecosystem (9+ libraries) used across 7+ countries and co-architected an iOS build system that cut CI/CD times by 45%.

  3. Jul 2021 — Jul 2022

    Senior Expert Architect · API, iOS & Android · Santander T&O España

    Defined architecture standards and system design for mobile apps (Android, iOS, Flutter) and microservices across Santander Group's European operations; patterns adopted by 5+ delivery teams.

  4. May 2020 — Jul 2021

    Senior Technical Lead · API, iOS & Android · Santander Tecnología Argentina

    Led the Digital Banking team and drove the migration from a legacy monolith to microservices (Kotlin, GraphQL, Spring WebFlux). Key contributor to a top-rated banking app on the App Store and Play Store.

  5. Aug 2015 — Mar 2020

    Mobile Apps Lead · iOS & Android · AFIP

    Directed an in-house team shipping 7+ iOS and Android apps (Swift, Java, React Native) for millions of taxpayers, and built an authenticated web portal serving 8M users/month with React and Spring Boot.

  6. Jan 2013 — May 2021

    Adjunct Professor & Researcher · Universidad de Buenos Aires

    Taught embedded systems, Android for IoT, and microcontroller programming for 8+ years, and co-authored published research on embedded and mobile systems at the LSIA lab.

Toolbox

Skills

Leadership & Strategy
Technical LeadershipEngineering StrategyPlatform EngineeringDeveloper ExperienceSystem DesignMentoring
Mobile & Cross-Platform
iOSAndroidSwiftKotlinFlutterJavaReact NativeModular SDKs
Experimentation & Analytics
Feature FlaggingA/B TestingRUMSession ReplayGTM (Server-Side)TealiumGA4Server-Driven UI
Backend & APIs
GraphQLRESTSpring BootSpring WebFluxMicroservices
Cloud & DevOps
AWS (Solutions Architect)CI/CDGitHub Actions
Systems
RustUniFFIEmbedded (C / AVR)Clean ArchitectureSOLID

Say hello

Get in touch

Contact page
Emaileaceto@pm.meGitHubgithub.com/eacetoLinkedInwww.linkedin.com/in/ezequielaceto