Principal Architect (D035248)

Referment; Warszawa; Hybrid; PLN 350,000 - 600,000; Full time

Benefits offered by this job

Equity participation

Private healthcare

Wellbeing support

Job summary

Referment is building a data-driven fintech platform with a strong emphasis on scalable architecture. As Principal Architect, you will own the architecture of the entire platform, including services, data, integrations, and deployment models.

You will report directly to the CTO and set technical direction while ensuring alignment with business goals as the platform scales. The role requires hands-on leadership in AI-enabled architecture, and the ability to defend decisions to engineers and bank

Qualifications

• Proven track record delivering platform-level architecture in production.
• Experience migrating from on-premises to cloud with measurable outcomes.
• Deep C# and .NET, MSSQL and PostgreSQL expertise.
• Hands-on with Azure, Kafka, Kubernetes, Helm, and distributed systems.
• Clear technical writing with RFCs or architecture decisions.
• Credible with engineers and bank architects.
• Familiarity with AI in architecture and AI-assisted tooling.

Responsibilities

• Define and own the target architecture, establishing the platform structure and clear service boundaries for engineers.
• Shape the transformation from on-premises to cloud, and from MSSQL to PostgreSQL.
• Document architectural decisions through RFCs, architecture decision records and strategy.
• Embed AI as a first-class architectural concern across services and pipelines.
• Explain and defend the architecture to engineers and bank-side architects.
• Make cross-environment decisions for on-premises and cloud during migration.

Skills

Distributed architecture

C#/.NET

SQL (MSSQL/PostgreSQL)

Azure

Kubernetes

Technical writing

AI in architecture

Tools

Kafka

Terraform

RabbitMQ

GCP

Python

Job description

Referment is working with a financial technology business that provides banks with the data intelligence behind personalised digital banking. Its platform runs in demanding client environments, with much of the estate currently deployed on-premises and an active migration towards cloud.

As Principal Architect, you'll own the architecture of the whole platform: services, data, integrations, deployment models and the boundaries between them. Reporting directly to the CTO, you'll set technical direction, make difficult trade-offs and remain accountable for whether the architecture supports the business as it scales.

The business is undertaking a funded platform transformation spanning performance, architecture and AI. This is not a review-and-advise position or a programme management role. You'll draft the target architecture, defend it with engineers and customers, and stay close to implementation so you can correct drift early. The work is about shaping the technical outcome while ensuring today's delivery remains consistent with the platform's longer-term direction.

The Role

• Define and own the target architecture, establishing the platform structure and clear service boundaries that engineers can use to make implementation decisions.
• Shape the technical transformation from on-premises to cloud, from MSSQL to PostgreSQL and from legacy systems to a coherent platform. Stay close enough to delivery to identify divergence before it becomes entrenched.
• Document architectural decisions through RFCs, architecture decision records and technical strategy. Write clearly enough that teams can understand the rationale, resolve debates and act on the agreed direction.
• Embed AI as a first-class architectural concern across services, data pipelines and the software development lifecycle, rather than treating it only as an additional feature.
• Explain and defend the architecture with both internal engineers and bank-side architects, balancing technical credibility with clear communication about trade-offs.
• Make decisions that work across on-premises client installations and cloud environments, maintaining practical awareness of both during the migration.

What We're Looking For

• Ownership of a distributed, data-heavy platform architecture in production, with significant customer expectations. Designing a system in isolation is not enough; you should be able to explain how your decisions held up in operation.
• Experience moving a live system from one architecture to another without stopping the business, with an honest account of the costs, compromises and lessons.
• Deep C# and .NET knowledge, strong MSSQL and PostgreSQL experience, and practical exposure to both on-premises and cloud systems. You'll need to read implementation code critically, not operate solely at diagram level.
• Hands-on understanding of Azure, Kafka, Kubernetes, Helm charts and distributed systems at scale.
• Clear technical writing, demonstrated through RFCs, decision records or public technical communication. You should be able to turn an architectural judgement into an explicit, usable decision.
• Credibility with engineers and customers, including bank architects who will challenge the proposed direction.
• An active approach to reasoning about how AI changes architecture and engineering practice, including use of AI-assisted tools such as Cursor and Claude Code.

Relevant Desirable Experience

• RabbitMQ, Terraform, GCP or Python.
• Fintech or another regulated industry where technical decisions must work within demanding client constraints.

Working Environment

This is a B2B contract engagement with two office days and three remote days each week. The source lists equity participation through an employee share option programme, private healthcare and support for wellbeing and everyday working costs. The role combines a direct reporting line to the CTO with authority to set technical direction and accountability for the resulting architecture.

Interview Process

A 30-minute screening call covers transformations you've led and what you learned. A 60-minute CTO discussion explores architecture, trade-offs and change at scale. A 90-minute architecture deep-dive uses a real platform problem, with AI tools welcome. The employer states that a decision or offer follows within ten days of the final interview.

This could suit a principal or platform architect who has already led a live technical transformation and wants whole-platform ownership while remaining close to code, engineering decisions and customer requirements.

#Referment