Software Engineer - Full-stack / Tooling Team

This role is suitable for a Middle to Senior full-stack software engineer experienced in building reliable, high-performance tooling for data-intensive systems. Required skills include strong frontend and backend development, proficiency with modern programming languages and frameworks, API and database design, testing, debugging, and an understanding of real-time or high-frequency data processing. The candidate should be familiar with developing trader and analyst tools, data visualization interfaces, internal configuration systems, scalable services, and maintaining strict code quality through reviews and production deployment.

How would you design a frontend application for visualizing high-frequency trading data in real time?

I would use streaming updates, client-side aggregation, and efficient rendering to avoid re-rendering the entire dataset. The design should include backpressure, bounded buffers, graceful degradation, and clear indicators for stale or delayed data.

How would you reduce latency when processing and displaying large streams of market data?

I would profile the full pipeline, minimize serialization and network overhead, batch noncritical updates, and keep hot-path processing efficient. On the frontend, virtualization, memoization, and selective updates can significantly reduce rendering cost.

What considerations are important when building tools that configure complex trading systems?

The tool should validate configuration both locally and on the server, clearly represent dependencies, and prevent unsafe or incomplete changes. Versioning, audit logs, previews, and rollback support are also essential for operational safety.

How would you design a reliable service that consumes data from multiple cryptocurrency exchanges?

I would isolate exchange-specific adapters behind a common interface and normalize symbols, timestamps, order types, and error formats. Each adapter should support reconnection, rate-limit handling, sequence validation, and observability for data gaps or inconsistencies.

How would you handle WebSocket disconnections in a real-time trading tool?

The client should detect missed heartbeats, reconnect with exponential backoff and jitter, and resubscribe automatically. After reconnecting, it should resynchronize state through a snapshot or replay mechanism rather than assuming incremental updates were not lost.

What techniques would you use to ensure consistency between a frontend tool and backend trading state?

I would treat the backend as the source of truth and use explicit versions, event sequences, or optimistic concurrency checks. The UI should distinguish pending, confirmed, rejected, and stale states and refresh affected data after mutations.

How would you test a full-stack application used by traders and data analysts?

I would combine unit tests for business rules, contract tests for APIs and exchange adapters, integration tests for persistence and messaging, and end-to-end tests for critical workflows. Load, latency, failure-recovery, and browser-performance tests are particularly important for real-time tools.

How would you investigate a production issue where a dashboard shows incorrect market data?

I would trace the data from the exchange adapter through normalization, transport, storage, and rendering, comparing timestamps, sequence numbers, and raw events at each stage. Structured logs, metrics, distributed tracing, and reproducible fixtures would help identify whether the issue is ingestion, transformation, caching, or presentation.

How would you secure internal applications that can modify trading configuration?

I would enforce strong authentication, role-based authorization, least-privilege access, and server-side validation for every mutation. Sensitive actions should require audit logging, clear confirmation, and ideally approval or two-person review for high-impact changes.

How would you improve code quality and maintainability in a fast-moving tooling team?

I would establish clear module boundaries, consistent interfaces, automated formatting and static analysis, meaningful tests, and focused code reviews. Shared domain models and documented engineering standards help prevent duplicated logic and inconsistent behavior across tools.

Join an innovative crypto-trading company building a high-performance platform that executes orders across 10+ exchanges and supports thousands of trades per hour. As a Full-stack Software Engineer on the Tooling team, you’ll create trader and analyst applications for real-time high-frequency data, visualization, and complex internal configuration systems. This is a full-time hybrid role in Slovakia or the Czech Republic; the technology stack and salary are not specified, but the opportunity offers exceptional production impact, challenging engineering work, and collaboration with an accomplished team.