Senior Python Engineer (Remote)

Warsaw · Remote ok

About this role

Position Summary:

We are looking for a talented Senior Python Engineer to join our team responsible for transaction monitoring and exploration. This is a fully remote role, and we welcome applications from anywhere in Europe. As part of our Nexus squad, you will play a critical role in streamlining clients’ operations and smoothing their investigations on the Crystal platform.

More details: crystalintelligence.com

Duties and responsibilities:

  • Owning the transaction monitoring part of the Crystal platform;

  • Improving stability and observability of the owned services;

  • Maintaining code to high-quality standards;

  • End-to-end feature design and implementation;

  • Coding, debugging, testing and delivering features and improvements in a continuous manner;

  • Providing code reviews, assistance and constructive feedback to other team members;

  • Performance optimizations (including database queries optimizations);

  • Refactoring code as necessary.


Required:

  • 8+ years of commercial experience developing Python backend services and APIs for the web;

  • Solid software architecture skills;

  • Strong knowledge of SQL/NoSQL databases and data architecture, including PostgreSQL;

  • Knowledge of testing principles at different levels of the system;

  • Experience in developing client-facing solutions;

  • Experience with distributed systems;

  • Product-oriented mindset;

  • Proficiency in English.


Would be a plus:

  • Experience with scalability and performance optimizations of large distributed systems.

  • Experience with systems operating on large data volumes;

  • Experience with the Flask framework;

  • Passion for cryptocurrencies and blockchain technologies.


No previous knowledge of Blockchain technology required.

Tech stack:

  • Redis, RabbitMQ, PostgreSQL, ClickHouse;

  • Kubernetes, AWS + Hetzner;

  • Python 3.14, Flask, Granian;

  • Datadog, Grafana.


You’ll get:

  • AI tool of your choice: Cursor or Claude Code.

Company at a glance

Crystal is a leading blockchain intelligence firm empowering financial institutions, law enforcement and regulators with real-time blockchain analysis, investigative and compliance solutions.

Our solution helps financial institutions comply with global anti-money laundering regulations efficiently. Investigators and government agencies leverage Crystal’s cutting-edge technology and unique real-time intelligence to solve crypto investigations. Available as a free blockchain explorer, SaaS, or API.

Founded2016
Team Size51-200 employees
WorkspaceRemote ok
IndustryData Security Software Products
Location
Lisbon, Portugal

Top Benefits

  • AI Tool Of Choice (Cursor Or Claude Code)

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