Senior Go Developer - Financial Systems

The Delio Core OS platform supports the full private markets lifecycle, from deal origination and execution through to ongoing portfolio monitoring and reporting.

This role sits specifically within the portfolio monitoring and analytics layer, focused on building high-performance systems that process complex financial data at scale. Our platform handles large volumes of capital, positions, and holdings with strict requirements around accuracy, auditability, and performance, and we are investing heavily in scalability, reliability, and long-term architectural growth.

We are looking for a highly skilled Go (Golang) Developer to design and build large-scale financial calculation services that power our platform.

This is not a typical web development role, this role is for someone who thrives in high-performance, data-intensive backend systems.

You will play a key role in building and scaling a core calculation engine that supports portfolio analytics and financial modelling.

Key responsibilities

• Design and develop high-performance services in Go (Golang)

• Build and optimise large-scale financial calculation engines

• Build systems that accurately process and reconcile high volumes of capital, positions, and holdings

• Architect systems for scalability, reliability, and low latency

• Work with complex, high-volume datasets and portfolio logic

• Collaborate with frontend/backend teams to integrate services

• Contribute to system design, performance tuning, and infrastructure decisions

Technical Requirements

Essential:

• Strong commercial experience with Go (Golang)

• Proven experience working within a high-data environment (e.g. fintech or similar data-intensive industries)

• Experience building scalable backend systems

• Strong understanding of data processing, performance optimisation, and system design

• Experience designing and working with APIs

Desirable:

• Experience in financial systems or portfolio management platforms

• Familiarity with microservices architecture

• Knowledge of distributed systems and Go concurrency patterns

• Experience with cloud infrastructure (AWS, GCP, or similar)

• Ability to leverage AI tools to improve development workflows and efficiency

• Experience supporting integration with a PHP Laravel-based presentation layer

• Ability to help bridge backend calculation services with frontend delivery

What We’re Not Looking For

• WordPress developers

• CRM-focused developers

• Generalist engineers without deep backend or data experience

This is a high-skill role focused on core system performance and scalability.

Ideal Candidate Profile

• Backend-first engineer with experience in data-heavy systems

• Strong problem solver with a focus on performance and scale

• Comfortable working in complex, high-volume data environments

• Interested in leveraging modern tooling, including AI-assisted development

• Able to take ownership of critical system components

Why Join Delio

• Work on mission-critical financial infrastructure

• Solve complex scaling and data challenges

• Be part of a high-calibre engineering environment

• Opportunity to shape the architecture of a growing platform

What We Offer

• Competitive salary based on experience

• Hybrid working – based in or around Cardiff. We operate a hybrid working model with a minimum 3 days per week in the office - with Wednesday and Thursday being obligatory office days

• A friendly, supportive and innovative team culture

• Opportunities for professional growth and training

What You Can Expect:

• 25 days holiday (plus bank holidays), increasing with length of service

• Extra day off for your birthday 

• Private medical insurance and Death-in-service benefit

• Defined contribution pension scheme