FH Solutions

We are looking for a Mobile Software Engineer to help build and evolve a decentralized mobile wallet powered by a deterministic Rust SDK. This role focuses primarily on Swift development while requiring strong systems thinking and comfort working across Swift  Rust FFI boundaries. 

- The tech stack that you will interact with will be Swift, Rust, Kotlin, Rust FFI, and Objective C, mostly in that order. 
- You will be working with engineers and developers on the mobile team within our org, Dash Core Group. 
- This is an opportunity to work remotely in a team that uses modern coding practices and operates without a centralized backend, prioritizing client-side verification and security. 

Responsibilities:
- Collaborate with engineers to design, implement, and ship new wallet features.
- Implement wallet features on top of a deterministic SDK, ensuring correctness and security across the full stack.Improve our mobile SDKs. 
- This may involve improvements to the foundational Rust SDK.
- We use AI-assisted development tools. 
- Engineers are expected to critically evaluate and validate all generated code.Improve our continuous integration.

Requirements Either: 
- 3+ years professional software engineering experience, with significant experience in Swift (production iOS apps). 
- Exceptional recent graduates with demonstrable systems, distributed systems, compiler, or cryptography experience.
- Strong understanding of deterministic state machines and ability to reason about correctness in financial or security-sensitive systems.
- Comfortable working across language boundaries (Swift  Rust FFI), including understanding of memory ownership, threading, and error propagation.
- Conceptual understanding of cryptographic primitives (hashes, signatures, key derivation, Merkle trees).
- Experience building mobile applications that rely on complex local business logic or SDKs.
- Strong debugging skills across stack boundaries (mobile  SDK  networking).
- Proficient with Git and modern collaborative workflows.
- Strong Linux/macOS command-line skills.Ability to work remotely in a self-directed environment.
- Strong written and spoken English.
- This is not a typical UI-focused mobile role. 
- Candidates should be comfortable reasoning about state, correctness, and security in adversarial environments.

Nice to Have: 
- Working knowledge of Rust.
- Experience working with Rust FFI or other foreign-function interfaces.
- Experience with Android development.Understanding of UTXO vs account-based blockchain models.
- Familiarity with SPV or client-side transaction verification.
- Experience with cryptographic or privacy-preserving systems.
- Background in distributed systems.
- Comfort verifying and correcting AI-generated code in security-sensitive environments.

We’re a growing product team building modern web solutions in the fintech and entertainment domains.

We’re looking for a motivated Junior/Middle React / Node.js Developer who’s eager to learn from experienced mentors and grow into a strong Full-Stack Engineer.

📍 Location: Warsaw, Poland (on-site)
🕐 Start: ASAP
 

Requirements:

•  1–3 years of experience with React, Node.js, and TypeScript
•  Understanding of RESTful APIs and CRUD operations
•  Experience with PostgreSQL or MongoDB
•  Good knowledge of HTML5, CSS3 (and preprocessors like SCSS)
•  Familiarity with Git and Agile development
•  English: Intermediate or higher (spoken communication required)

Nice to have:

• Familiarity with CI/CD pipelines
• Basic Docker or AWS experience

Responsibilities:

• Development and maintenance of Front-end applications using React and Web Components;
• Development Backend using Node.js
• Optimization of application performance and scalability.
• Testing and debugging of code.
• Participation in technical discussions and collaborative development.

CONDITIONS:

— The trial period lasts 3 months;

— 15 vacation days per year included (1.25 days are charged every month);

— 5 sick days per year included.
 

We offer:

• On-site position in Warsaw
• Mentorship from senior developers
• Real growth path from Junior to Middle level
• Friendly team and stable environment
• Competitive salary (discussed individually)

💬 If you are ready to join our team and work on exciting projects in Full-Stack development using React / Node.js, we invite you to submit your resume. Join us and showcase your talent in building high-quality, scalable web and mobile applications.

8+ years of commercial mobile application development experience, with a significant portion using Flutter/Dart

Experience working with large codebases (50k+ lines) and long-lived projects

Strong understanding of mobile application architectural patterns and ability to make architectural decisions

State Management & Architecture

Strong proficiency in Riverpod — providers, notifiers, AsyncValue, caching and invalidation

Experience with reactive programming using RxDart (Streams, BehaviorSubject, stream combination)

Navigation with GoRouter — deep linking, nested routes, guards, redirect logic

Local Database & Offline Mode

Practical experience with Drift (code generation, migrations, complex queries, joins, transactions)

Understanding of offline-first architecture principles: data synchronization, conflict resolution, operation queues

Experience with SQLite; familiarity with database encryption (SQLCipher) is a plus

Networking

Strong knowledge of Dio — interceptors (auth, retry, logging), error handling, cancel tokens

Understanding of REST APIs, authorization tokens, refresh token logic

Experience using flutter_secure_storage for secure credential storage

Firebase

Integration and configuration of Firebase: Analytics, Crashlytics, Cloud Messaging (push notifications), Remote Config, Performance Monitoring

Experience debugging push notifications on both platforms

Device & Native APIs

Camera, gallery, file system (image_picker, file_picker, path_provider)

Geolocation and maps (Geolocator, Google Maps Flutter, map_launcher)

QR/barcode scanning (mobile_scanner)

Permissions (permission_handler), deep links (app_links)

Background file downloads (background_downloader)

Testing

Experience writing unit tests for business logic, services, and Riverpod providers

Experience with widget testing for UI components and user scenarios

Proficiency with mockito — dependency mocking, stubs, call verification

Testing asynchronous code: fake_async, stream matchers, timers

Experience or willingness to work with integration/E2E testing (Patrol or similar)

Understanding what and when to test — balancing coverage and maintenance cost

Native Integration

Experience integrating native libraries for Android (NDK, JNI, Kotlin/Java) and iOS (Swift/Objective-C, CocoaPods, XCFramework)

Writing Platform Channels (MethodChannel, EventChannel) to connect Flutter with native code

Ability to create Flutter plugins with native wrappers for both platforms

Experience debugging platform-specific issues — build, linking, native dependency compatibility

Code Quality & Code Review

Ability to conduct meaningful code reviews focusing on reliability, performance, and readability

Ability to identify async/await issues, memory leaks, and race conditions during review

CI/CD

Experience setting up and maintaining CI/CD for mobile applications (Fastlane, Codemagic, GitHub Actions or similar)

Automation of builds, signing, and publishing to the App Store / Google Play

Must‑Have Skills:

Strong expertise in Angular + strongly typed TypeScript

Experience with RxJS and Angular Signals

Frontend unit testing (Jest/Karma/Jasmine/Playwright)

Authentication & Authorization (OIDC, JWT, token handling)

REST API integration & error handling

Professional Git workflow

Practical experience with Docker

Basic understanding of Azure and Azure DevOps

Nice‑to‑Have:

AG Grid, PrimeNG

Azure Cloud (hands‑on)

Terraform

Python scripting

UX/UI collaboration (Figma)

Interview process:
1. English-intro (15min)
2. Submit form
3. Interview with HR and CTO (1.5h)

Required Skills & Experience

• Strong expertise in Terraform, including module development and infrastructure

automation.

• Hands-on experience with GitHub Enterprise and cloud providers AWS and Azure.

• Solid understanding of CI/CD, cloud networking, and infrastructure as code

principles.

• Familiarity with cloud security practices, including IAM (Identity and Access

Management), RBAC (Role-Based Access Control), and CAS (Cloud Access Security)

concepts and implementation.

• Knowledge of other Terraform providers such as Databricks is a plus but not

mandatory.

• Excellent communication and collaboration skills, with the ability to work across

teams and stakeholders.

Preferred qualifications

• Work experience with Amazon Web Services (AWS): Ideally 5 years

•  Work experience with Python: 5 years

• Work experience with GitHub: Ideally 5+ years

• Work experience with Terraform: Ideally 5+ years