SFox GmbH

Description

Build and operate real-time data pipelines and execution systems for live crypto trading across centralized and decentralized venues.

What You’ll Do

- Ingest real-time market and on-chain data streams

- Build low-latency execution for perps, prediction markets, DeFi

- Work with blockchain infra, APIs, WebSockets, and contracts

- Implement safe, hierarchical key management for hot wallets

- Maintain databases and cloud systems

- Productionize strategies with researchers

- Use LLMs and AI tools to ship faster

- Improve performance, monitoring, and reliability

If you build fast systems, care about security, and move quickly, you’ll fit right in.

There is a need for your to have occasional business trips to Unite Emirates (Dubai)

Description

Research and prototype profitable trading strategies across crypto perps, prediction markets, and emerging DeFi protocols using granular data and fast, AI-driven iteration.

What You’ll Do

- Analyze order books, funding, liquidations, and DeFi mechanics

- Build fair-value models and mispricing signals across venues

- Find features using statistical, ML, and AI-assisted techniques

- Test market-making, arbitrage, yield, and idiosyncratic strategies

- Work with engineers to deploy research into production

- Use LLMs and modern AI tools to iterate quickly

- Refine strategies using live performance and new data

If you like moving fast and turning data into PnL, this role is for you.

There is a need for your to have occasional business trips to Unite Emirates (Dubai)

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

- Modernize legacy systems via redesign and refactoring.
- Develop UI using React + Nexus design system.
- Build APIs with proper security and lifecycle governance. - Design reusable component libraries and UI frameworks. - Collaborate with UX, product, and architecture teams. - Optimize frontend and backend performance.

- Support public API documentation and governance.

Skills

- Strong Java + Spring Boot backend capability.
- Expertise in React, TypeScript, Nexus UI components.
- Experience with modernization and migration projects.
- Understanding of microservice and API design.
- Familiarity with CI/CD, linting, testing frameworks.
- Knowledge of frontend security and performance patterns. - Good collaboration across UX and backend teams.

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

DevOps Engineer – 1 Position 10+ yrs exp | 2.5-3 LPM

- Design and maintain CI/CD pipelines for backend, data, and UI apps. - Manage Kubernetes workloads and deployments.
- Implement monitoring, alerting, and observability dashboards.
- Automate Infrastructure provisioning using IaC.

- Support release operations and environment stability.

- Troubleshoot deployment and performance issues.

- Collaborate with development and SRE teams.

Skills

- Experience with CI/CD tools (GitHub Actions, ADO).
- Strong Kubernetes and containerization knowledge.
- Familiarity with Helm, YAML, and deployment patterns. - Understanding of observability stacks (logging, metrics). - Knowledge of Terraform/Bicep or other IaC tooling.
- Basic networking and security fundamentals.
- Good scripting skills (Shell/Python).

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

- Develop high-quality Java microservices using Spring Boot.
- Build Kafka producers, consumers, and stream-processing apps.
- Design event-driven architectures with reliability and performance.
- Implement service resiliency patterns such as retries and circuit breakers. - Collaborate on distributed system design and integration.

• Ensure logging, tracing, and monitoring of backend services.

• Support performance tuning and root cause analysis.

   

• Skills
  - Strong in Java, Spring Boot, microservices patterns.
  - Hands-on Kafka development—streams, partitions, consumer groups. - Knowledge of distributed systems architecture.
  - Familiarity with Docker, cloud-native packaging.
  - Experience in REST APIs, schema evolution, and contracts.
  - Understanding of observability (logs, metrics, traces).
  - Good debugging and performance optimization skills.

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

Design and develop full-stack applications using Java + React.
- Build REST APIs following microservice standards.
- Implement user interfaces using Nexus design system.
- Refactor legacy components for modernization and performance. - Collaborate with architects to define scalable solutions.

- Participate in code reviews, testing, and sprint ceremonies.
- Optimize application reliability, performance, and maintainability. 

Skills
- Strong in Java, Spring Boot, REST API development. (4+ years of commercial experience)
- Expertise in React, JavaScript/TypeScript, UI state management.
- Experience with Nexus design system or similar component systems. - Understanding of cloud-native development and containerization.
- Knowledge of CI/CD, Git workflows, automated testing.
- Familiarity with security best practices for APIs.
- Good understanding of system integration patterns.

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

Design and develop full-stack applications using Java + React.
- Build REST APIs following microservice standards.
- Implement user interfaces using Nexus design system.
- Refactor legacy components for modernization and performance. - Collaborate with architects to define scalable solutions.

- Participate in code reviews, testing, and sprint ceremonies.
- Optimize application reliability, performance, and maintainability. 

Skills
- Strong in Java, Spring Boot, REST API development. (4+ years of commercial experience)
- Expertise in React, JavaScript/TypeScript, UI state management.
- Experience with Nexus design system or similar component systems. - Understanding of cloud-native development and containerization.
- Knowledge of CI/CD, Git workflows, automated testing.
- Familiarity with security best practices for APIs.
- Good understanding of system integration patterns.

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

- Build responsive UI experiences using React + Nexus components. - Ensure accessibility (WCAG) and UX compliance.
- Integrate front-end with backend APIs.
- Optimize UI for performance and cross-device compatibility.

- Implement reusable UI components and design patterns.

- Participate in UI code reviews and testing.

- Troubleshoot and resolve UI defects.

Skills

- Strong React, TypeScript, modern frontend tooling.
- Experience with design systems (Nexus preferred).
- Understanding of accessibility standards (WCAG).
- Knowledge of frontend performance optimization.
- Familiarity with API integration & authentication flows. - Experience with Jest/React Testing Library/Playwright. - Strong CSS and responsive design skills.

Please read before applying:

The client is building a product in the bank/investment/brokerage systems niche, and their investors have strict security and compliance requirements, where every person will go through a background check.

What does this mean?

Before making an offer, they will check whether you have violated any EU laws.

Why Poland?

The client has teams in the USA, Ireland, and Poland.

For background check — you must be a taxpayer in Poland for 2+ years.

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

- Develop and execute automated UI & API test suites.
- Lead regression testing strategy and quality governance.
- Validate UI/UX behavior and accessibility.
- Collaborate with engineering teams on defect resolution.
- Maintain test documentation and test metrics.
- Support UAT, release readiness, and quality gates.
- Test cloud-native deployments and integrations.
Skills
- Strong automation testing experience (Playwright/WebDriver). - Understanding of regression and integration testing design.
- Knowledge of accessibility and UI validation.
- Familiarity with API testing tools (Postman, REST Assured).
- CI/CD test execution knowledge.
- Basic debugging & log analysis skills.
- Experience creating reusable test assets.

Please read before applying:

The client is building a product in the bank/investment/brokerage systems niche, and their investors have strict security and compliance requirements, where every person will go through a background check.

What does this mean?

Before making an offer, they will check whether you have violated any EU laws.

Why Poland?

The client has teams in the USA, Ireland, and Poland.

For background check — you must be a taxpayer in Poland for 2+ years.