Senior Backend Engineer - Api Trading EMEA F - M - D H/F - 75

Founded in 2020, Flowdesk is a regulated, full-service digital asset trading and technology firm that specializes in market making, OTC, and treasury management services.

With offices globally, we have engineered a trading infrastructure that integrates more than 120 centralized and decentralized exchanges. Combining proprietary technology with significant experience from traditional markets and algorithmic trading, Flowdesk brings control and transparency to digital asset markets.Flowdesk's mission is to build a global financial institution for digital assets, one designed from the ground up for market integrity and efficiency.

To achieve this in a rapidly evolving market, we apply a disciplined, first-principles approach to everything we do. This approach is embedded in our core services, from institutional liquidity provision, trading solutions, OTC execution to our comprehensive treasury management offerings. This is how we cut through the noise and build robust and scalable systems across all our business lines.

We seek individuals who are driven by this systematic approach. Joining Flowdesk means you will be a key contributor in building and scaling a more transparent and efficient financial markets infrastructure.

At Flowdesk, our APIs are how the outside world trades with us.

We're opening a new role for a Senior Software Engineer - API Trading to design, build, and scale our public trading APIs to a truly competitive level. You'll own the API surface that clients integrate with (REST, WebSocket, FIX), ensure it's clear and well-documented, and work closely with trading, product, and security teams to make it a best-in-class experience.

This is a hands-on, senior individual contributor role with strong technical ownership and cross-team collaboration.

Your mission will be to

Design and build competitive trading APIs

- Architect and implement public trading APIs (REST, WebSocket, and FIX) in Rust.
- Ensure low-latency, high-throughput access to trading workflows (orders, balances, positions, executions).

Own the API lifecycle end-to-end

- Define and maintain OpenAPI specifications and other interface contracts.
- Keep APIs consistent, versioned, and easy to integrate for external clients.
- Drive clear, accurate, and up-to-date API documentation that external developers actually want to read.

Build secure, robust authentication flows

- Design and implement authentication and authorization for public trading APIs.
- Apply best practices around key management, signatures, rate limiting, replay protection, and abuse prevention.

Collaborate across trading, product, and engineering

- Work closely with internal stakeholders (including Jing and Tony) to understand trading needs and constraints.
- Translate trading and product requirements into clean API designs and reliable backend flows.
- Partner with frontend / tooling teams (TypeScript) to ensure smooth end-to-end integration.

Raise the bar on reliability and quality

- Ensure APIs are observable, well-tested, and resilient under peak load.
- Contribute to standards, patterns, and tooling for API development across the team.
- Help review code, mentor teammates, and share best practices in Rust, security, and API design.