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Role description

About Citadel Securities

Citadel Securities is the next-generation capital markets firm and a leading global market maker. We provide institutional and retail investors with the liquidity they need to trade a broad array of equity and fixed income products in any market condition. The brightest minds in finance, science and technology use powerful, advanced analytics to solve the market’s most critical challenges, turning big ideas into real-world outcomes.

Role Overview:

We’re looking for driven innovators and optimizers who are excited about cutting-edge technology and making a measurable impact. If you’re passionate, obsessed with performance, and excited to work where nanoseconds matter.

Responsibilities
:

Solve What Matters:
Break down intricate challenges and deliver clear, elegant solutions that drive real world outcomes
Build and Scale:
Design, build and maintain high performance systems that are the backbone of our trading infrastructure
Optimize Everything:
Continuously push the limits of latency, reliability, and throughput in a distributed environment
Partner and Deliver:
Collaborate directly with traders, researchers, and fellow engineers to deliver ideas into production
Own it in production:
Take pride in running your code live - Monitoring, supporting and improving it every day

Qualifications
:

Deep experience in C++ with a passion for clean, performant code
A strong grasp of multithreading, concurrency, and distributed systems
Curiosity to explore how things work and a drive to improve them
Clear, thoughtful communication and the ability to thrive in a high ownership environment
Bachelor’s (or higher) degree in a Computer Science, Engineering or related field
Background in Trading or finance is a plus but not a requirement

This role requires you to be based in one of our global offices listed below. If you are not currently located in one of these cities, we offer a comprehensive relocation package to support your move:

Gurugram, Hong Kong, London, Miami, New York, Shanghai, Singapore, Sydney, Zurich.

Opportunities may be available from time to time in any location in which the business is based for suitable candidates. If you are interested in a career with Citadel, please share your details and we will contact you if there is a vacancy available.

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.

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Mobile Developer

Senior iOS Developer

Immoweb

Remotefulltime

Apply on the employer's site

Role description

Build the platform where Belgium feels at home.
For over 30 years, Immoweb has been more than just a platform; we are the digital heartbeat of the Belgian real estate market. From first apartments to forever homes, we bridge the gap between dreams and reality for millions of users every month.

Our mission: to inspire, guide and close every home move in Belgium. We make real estate fast, transparent, and stress-free through world-class technology and human-centric support. We are dedicated to connecting people with their property goals, ensuring that at Immoweb, your work has an immediate, nationwide impact from day one.

Your Mission
Who we are
Immoweb is Belgium's leading real estate portal, part of AVIV Group, Europe's largest network of digital real estate marketplaces. Every month, hundreds of thousands of people use our iOS app to search, save, and get alerted about the properties that matter to them. We're currently modernising our native codebase — moving from an older UIKit/MVVM stack to a leaner, more testable Swift 6 architecture — while keeping the app running reliably for our existing user base.

The Seeker squad
You'll join Seeker, a full-stack squad (iOS, Android, Web, Backend, Design) that owns the end-to-end property search and discovery experience: search, filters, saved searches and alerts, and the property detail page. We work in close collaboration with product and design, ship through CI/CD, and care about shipping quality features that scale to hundreds of thousands of daily users.

What You'll Do

Design and build native iOS features for the Immoweb app, working closely with our Android, Web, Backend, and Design counterparts on shared feature sets.
Contribute to our ongoing migration from UIKit/legacy patterns to SwiftUI, @Observable, and Point-Free's modular architecture libraries.
Write clean, testable code (XCTest / Swift Testing) and review your teammates' work.
Continuously improve app quality, performance, and stability for a large, active user base.
Ship through our CI/CD pipeline in close collaboration with product managers.
Be a driving force behind new features — search relevance, alerts, personalisation — and technical improvements alike.
Share knowledge with the team and help raise the bar on iOS engineering practices across Immoweb.

What You Bring

Solid, hands-on experience building production iOS apps in Swift, ideally including Swift 6 and iOS 18.
Strong SwiftUI experience; comfort with @Observable and modern state management patterns.
Good understanding of Swift Concurrency (async/await); exposure to RxSwift is a plus, as parts of our codebase are mid-migration.
Familiarity with, or willingness to adopt, Point-Free's à la carte libraries (swift-dependencies, swift-sharing, swift-navigation, swift-case-paths).
Experience consuming RESTful APIs; familiarity with Moya is a plus.
A solid grasp of software architecture and Clean Architecture principles.
Basic knowledge of unit and UI testing (XCTest / Swift Testing).
Comfort working with Git and collaborative workflows (GitHub).
Excellent communication skills; you're a team player who shares knowledge openly.
English is mandatory; French or Dutch are strong assets given our Belgian market.

Nice to have

Experience with Swift Package Manager.
Familiarity with the Composable Architecture (TCA) or similar unidirectional architectures.
Experience with A/B testing and product analytics/tracking.
Experience with Bitrise or similar CI/CD tooling.
Knowledge of accessibility best practices.
Experience contributing to or consuming a design system.
Familiarity with Jira and Confluence; experience working in Scrum.

What We Offer

A friendly, quality-first engineering culture where you'll help modernise a widely-used app.
Real ownership over features used by hundreds of thousands of people every day.
Hybrid working, with the option to be based in Brussels or Bucharest.
Opportunities for growth — training, conferences, and mentorship within a full-stack squad.
The autonomy to work in the way that makes you most productive, and a say in the tools you use.

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.