Core Engineer - DeFi - London (F/M/D)

Flowdesk; City Of London; On-site; GBP 80,000 - 100,000; Full time

Job summary

A leading financial technology firm in London is looking for a Core Engineer to join their team. The successful candidate will lead the design and delivery of a new internal platform, working on DeFi integrations and enhancing booking features. Ideal candidates have a strong programming background in languages such as Go or C++, experience with DeFi protocols, and a proven record of scalable systems development. This position offers a dynamic work environment and comprehensive benefits.

Benefits

International environment

Pension

100% health coverage

Team events and offsites

Qualifications

• Experience with lifecycle of crypto asset classes.
• Integration with DeFi protocols like Uniswap v3, Curve, Aave.
• Strong OO programming background and API design experience.

Responsibilities

• Integrate DeFi protocols for real-time back office system.
• Implement and enhance features in booking engine.
• Automate reconciliation of trading activities.
• Gather requirements for reporting and internal tools.
• Expose APIs and maintain backward compatibility.

Skills

Lifecycle knowledge of crypto asset classes

Hands-on integration with DeFi protocols

Proven track record delivering scalable systems

Comfortable partnering with stakeholders

Tools

Go

C++

C#

Java

Rust

Typescript

Python

Postgres

GCP

AWS

Azure

Job description

Overview

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.

Flowdesk is scaling fast, and behind every world-class trading operation is a core engineering team who provide the single source of truth and a scalable platform for business units to leverage. We’re hiring a Core Engineer to join the team and help lead the design and delivery of a new internal platform.

Mission

Be a key player in the newly formed Core Engineering team at Flowdesk to build a world class back office system which will serve as the backbone for Flowdesk's systems. Work alongside a seasoned team with deep product, buy‑side, and sell‑side experience in both Crypto and TradFi.

Tasks

• DeFi Integrations - Collect all necessary on-chain data and integrate with decentralized protocols to power an accurate, real-time back office system. You will be responsible for ensuring management has a comprehensive, up-to-date view of all on-chain assets. This includes owning the full process from requirements analysis, task specification, implementation, to post-production support.
• Core Booking / Aggregation - Implement and enhance features in the core booking and aggregation engine (Realised / Unrealised P&L, Balances etc) ensuring performance, reliability and correctness.
• Reconciliation - Automate reconciliation of all trading and treasury activity across the firm implementing data feeds from internal systems, banking, exchanges and custodians.
• Reporting - Work closely with the Finance and other internal users to gather and refine requirements, plan milestones, demo progress, and coordinate cutovers from manual / legacy workflows.
• Data products and APIs - Expose well-versioned APIs and event streams for downstream consumers; maintain backward compatibility and schema evolution.

Ways of working

• Follow established architecture and coding standards; participate in RFCs/design reviews and propose incremental improvements within existing patterns.
• Write clean, well-documented code and meaningful tests.
• Contribute to PR reviews; maintain up-to-date technical docs and diagrams.
• Own components end-to-end from spec to production support.

Must Haves – Experience

• Lifecycle knowledge of crypto asset classes: spot, perpetuals, futures, and options (including DeFi implementations).
• Hands-on integration with DeFi protocols (DEX/AMM, lending, derivatives) such as Uniswap v3, Curve, Aave.
• Proven track record delivering scalable, reliable systems in production.
• Comfortable partnering with internal stakeholders across Trading, Ops, Compliance, and Engineering.

Must Haves – Technical

• Strong OO background in one or more: Go, C++, C#, Java or Rust.
• Experience with Typescript and Python.
• API design (versioning, backwards compatibility, observability).
• Postgres schema design and query optimization.
• Experience with message queue / pub-sub systems.
• Familiarity with cloud environments (GCP, AWS, Azure), modern CI/CD and containerization.

Nice-to-Haves – Experience

• Built or maintained position-keeping / accounting systems (PnL, accounting methods, pricing, greeks).
• Centralized reference data platforms (assets, networks, instruments), consistent symbology and instrument economics.
• Trading, risk, or back-office systems, ideally in regulated environments.

Benefits

• International environment (English is the main language)
• Pension
• 100% health coverage
• Team events and offsites

Recruitment Process

1. HR interview (30')
2. Technical interview - Hiring Manager (30')
3. Take home assignment + Live coding session (90')
4. Team Member Technical (45')
5. CTO (45")
6. Chat with the Head of People (30')