Python Developer - Risk and Data

Python Developer - Risk and Data

Full-Time On-site
JUXT

JUXT is partnering with a leading global commodities trading firm to build its new core data platform for real-time and end-of-day market data.

During this mission we’ll replace an existing system with a new highly scalable cloud-native data platform, without breaking client applications that rely on this data today. We’ll build new data ingestion pipelines to consume from a wide variety of market data providers. We will also build new query capabilities that are compatible with existing APIs, so that client applications keep working unchanged.

This is a greenfield build with a pragmatic team that likes to prove solutions quickly and iterate. You’ll work alongside highly experienced engineers to plan the migration, build and deploy new systems, analyse existing traffic and prioritise, then expand feeds and query APIs to cover new use-cases.

What you’ll work on

  • Building the feed ingestion subsystem: event-driven connectors pulling data directly from external market data providers.
  • Building query APIs using modern scalable data technologies like Clickhouse and S3 Tables/Iceberg with Athena. Experience with other massively scalable data tech is beneficial (QuestDB, Snowflake, DuckDB).
  • Building an intercepting proxy to intelligently direct traffic towards new query services. Achieving faithful API compatibility so that clients can continue to operate correctly.
  • Gathering and analysing metrics and request payloads to discover and survey existing data clients. Validating the design end-to-end against real client requests, and rolling out new systems in carefully staged steps.
  • End-to-end observability across every component: logs, metrics and traces into ClickStack and Grafana, augmented by AWS observability services.
  • Working carefully to guide the client, learning through discovery sessions, and thinking carefully about platform architecture (streaming vs request-response use cases, staged and low-risk roll-outs, tracking data licenses, high-frequency feed downsampling).

Tech stack you’ll be working with

  • Data platform: AWS (S3, S3 Tables, Athena), ClickHouse, Airflow.
  • Interception and networking: Envoy, DNS, TLS, X.509, internal CAs.
  • Ingestion: event-driven services, and market data sources.
  • Observability: ClickStack, Grafana, AWS observability services.
  • AI tools: AI-assisted development with recent models is a normal part of how we work.

What we’re looking for

  • A strong senior backend engineer, comfortable across the languages in play on a data platform (primarily Python; languages like Java, Golang Rust, are a bonus) and experienced in building production data-intensive services.
  • Real experience with data pipelines and event-driven ingestion: connectors, schedulers, idempotency, backfill, and the operational care that feeds demand.
  • Solid networking fundamentals: DNS, TLS and certificates, OSI model, TCP packet analysis, HTTP proxying — enough to reason confidently about a transparent interception layer and debug it when reality intrudes.
  • Experience with scalable cloud data platforms, ideally AWS: object storage, table formats, query engines.
  • Strong testing discipline. Validation, reconciliation, and careful roll-out.
  • High autonomy and clear communication: a small senior team, embedded with the client, making pragmatic decisions and explaining them well. You will need to take ownership of significant tasks, design solutions and deliver.

Who this role suits

This suits an engineer who likes owning a hard problem end-to-end and building end-to-end prototypes to prove solutions quickly. You need experience across many platform architectures and network configurations, as the project combines systems work (transparent proxying, TLS, API fidelity) and data platform work (feeds, storage, serving). You’ll be well-connected to measures of progress (real traffic served, real use-cases migrated to the new data platform). You should be comfortable in a small, senior, high-trust team working directly with a client.

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Python Developer - Risk and Data employer: JUXT

At JUXT, we pride ourselves on being an excellent employer by fostering a culture of innovation and collaboration. Our London-based teams enjoy the autonomy to make impactful technical decisions while working on exciting greenfield projects for top financial institutions. With a strong focus on employee growth and development, we offer opportunities for continuous learning and career advancement in a supportive environment.

JUXT

Contact Details:

JUXT Recruitment Team