Jobs, fresher vacancy - Core Engineer - DeFi Integration • UK

Company: Selby Jennings London

UK

We're partnering with a rapidly scaling fintech firm that is building a next-generation financial institution for digital assets. Their mission is to create a transparent and efficient infrastructure for global markets, applying a disciplined, first-principles approach across all business lines-from trading and liquidity provision to treasury and OTC execution. As part of their expansion, they are hiring a Core Engineer to join a newly formed team focused on building a world-class internal platform. This team underpins the firm's trading operations and provides scalable systems for business units to leverage. Key Responsibilities DeFi Integrations: Build real-time back-office systems by collecting and integrating on-chain data from decentralized protocols. Own the full lifecycle from requirements to post-production support. Core Booking & Aggregation: Enhance the booking engine for P&L, balances, and other financial metrics with a focus on performance and reliability. Reconciliation: Automate reconciliation across trading and treasury activities using data feeds from internal systems, exchanges, custodians, and banks. Reporting: Collaborate with Finance and other stakeholders to refine requirements, plan milestones, and transition from legacy workflows. Data Products & APIs: Develop well-versioned APIs and event streams for downstream systems, ensuring schema evolution and backward compatibility. Ways of Working Follow established architecture and coding standards. Write clean, well-documented code with meaningful tests. Participate in design reviews and contribute to technical documentation. Own components end-to-end, from specification to production support. Ideal Candidate Profile Experience Deep understanding of crypto asset classes (spot, perpetuals, futures, options). Hands-on experience integrating with DeFi protocols (e.g., Uniswap v3, Curve, Aave). Proven success delivering scalable, reliable systems in production. Comfortable working cross-functionally with Trading, Ops, Compliance, and Engineering. Technical Skills Strong object-oriented programming background in Go, C++, C#, Java, or Rust. Experience with Typescript and Python. API design expertise (versioning, observability, compatibility). Proficiency in Postgres schema design and query optimization. Familiarity with pub-sub systems and cloud environments (GCP, AWS, Azure). Nice to Have Experience building or maintaining accounting/position-keeping systems. Knowledge of centralized reference data platforms and instrument symbology. Exposure to trading, risk, or back-office systems in regulated environments. Apply Now!