Senior Software Engineer - ClickHouse New Helsinki, Uusimaa, Finland

Aiven; Helsinki; Hybrid; EUR 90,000 - 130,000; Full time

Benefits offered by this job

Equity plan

Hybrid work policy

Equipment provided

PD budget

Wellbeing program

Time off policy

Global benefits

Job summary

Aiven is seeking a Senior or Staff Backend Engineer to anchor the ClickHouse team in Helsinki. You will own end-to-end platform problems, from database internals to data engineering tooling, influencing the roadmap for ClickHouse and its ecosystem.

You will mentor engineers, author RFCs, and drive multi-quarter initiatives, while balancing production reliability with innovative architectural work in a hybrid, Helsinki-based setup.

Qualifications

• Expert Python development skills: production-grade async Python, modular design.
• ClickHouse experience: operating at scale, optimization, upstream contributions.
• C++: ability to read and contribute to database engine code.
• Deep database internals knowledge: replication, storage engines, backup/restore semantics.
• Distributed systems depth: coordination services, race conditions, multi-AZ/region.
• Data engineering experience: streaming pipelines, schema management, reliable data movement.
• Strong Linux and cloud fundamentals: object storage, networking, TLS, debugging.
• Track record of technical leadership: RFCs/design docs, mentoring.
• Product sense: link engineering decisions to customer impact and roadmap.
• Experience with AI coding tools: leveraging AI in development.

Responsibilities

• Design and lead platform initiatives: migrations, backup/restore, topology, sharding.
• Build data engineering tooling around ClickHouse: streaming pipelines, schema evolution, integration frameworks.
• Own ClickHouse version lifecycle: qualify releases, diagnose issues, GA evolution.
• Debug deep into the stack: ClickHouse internals, distributed coordination, networking, TLS.
• Write RFCs and drive architectural decisions beyond the team.
• Influence roadmap: scope epics, plan deliverables, consider commercial aspects.
• Mentor engineers through reviews and pairing to multiply the team.
• Maintain production reliability: incident response, observability, CI performance.

Skills

Python development

ClickHouse experience

C++

Database internals

Distributed systems

Data engineering pipelines

Linux & cloud fundamentals

Technical leadership

Product sense

English fluency

AI coding tools

Tools

ZooKeeper / Keeper

Kafka

Git

Job description

We’re a global team of over 400+ people, working together to push the boundaries of open-source technology and multi-cloud solutions. Our vision is to help developers, builders, and creators bring their ideas to life with speed and simplicity, by providing a cloud data platform that makes open-source databases, search, streaming, and application infrastructure easily accessible to everyone.

The Role

We're looking for a Senior or Staff Backend Engineer to anchor our small, focused ClickHouse team. You'll own hard technical problems end to end on the platform behind our managed ClickHouse service - from database internals and backup/restore correctness to the data engineering tooling that connects ClickHouse to the wider ecosystem.

This is a role with real technical ownership. You'll write RFCs and design documents that change how we build, scope and lead multi-quarter initiatives, and influence the product roadmap for ClickHouse and its ecosystem - streaming ingestion, CDC, benchmarking, and analytics tooling. You'll also mentor the engineers around you and raise the bar for how the team works.

We expect you to be equally comfortable designing a new architecture and diving into a production incident - reading ClickHouse source code, untangling a replication race condition, or root-causing a flaky distributed test.

What You'll Do

• Design and lead major platform initiatives: think coordination-service migrations (ZooKeeper → ClickHouse Keeper), backup/restore architecture, cluster topology, sharding, and node lifecycle management
• Build data engineering tooling around ClickHouse - streaming ingestion pipelines (Kafka → ClickHouse, Postgres → ClickHouse), schema conversion and evolution, integration frameworks, and fault-isolation between data sources
• Own the ClickHouse version lifecycle: qualify new LTS releases, diagnose upstream regressions, and take releases from early availability to GA
• Debug deep into the stack - ClickHouse internals (replication, access control, MergeTree, materialized views), distributed coordination, object storage (S3/GCS/Azure), DNS and networking, TLS
• Write RFCs and drive architectural decisions that extend beyond the team, including security and infrastructure changes
• Influence the roadmap: scope epics, break down initiatives into deliverable work, and shape what the team builds next - including commercial aspects like plans, sizing, and capacity
• Mentor engineers on the team through design reviews, code reviews, and pairing - multiply the team, don't just add to it
• Keep the lights on with pride: production incident response, observability improvements, CI performance, and test reliability are part of the craft

What We're Looking For

Must have:

• Expert Python development skills - you write clean, production-grade async Python and have architected substantial systems with it, including decomposing large codebases into well-factored components
• ClickHouse experience - operating it at scale, query optimization, or upstream contributions
• C++ - ability to read and contribute to database engine code
• Deep database internals knowledge - replication, access control, storage engines, backup/restore semantics; you're comfortable reading database source code (ClickHouse is C++) to root-cause behavior
• Distributed systems depth - consensus/coordination services (ZooKeeper, Keeper), race conditions, cluster topology, and the failure modes of services running across nodes, AZs, and regions
• Data engineering experience - streaming pipelines, Kafka, schema management (Avro or similar), and the operational realities of moving data between systems reliably
• Strong Linux and cloud fundamentals - object storage (S3-compatible), networking/DNS, TLS/certificates, systemd-level debugging
• Track record of technical leadership - RFCs or design docs you've authored, multi-quarter initiatives you've scoped and led, engineers you've mentored
• Product sense – you can connect engineering decisions to customer impact, pricing, and roadmap priorities
• Experience with AI coding tools - you actively use AI-assisted development and help others get the most from it
• Fluent English – written and verbal

Nice to have:

• CDC and analytics ecosystem experience - Debezium-style pipelines, Iceberg, lakehouse formats
• Benchmarking and performance engineering - capacity planning, sizing methodology
• Security engineering exposure – certificate management, access-control models

Why This Role

• Real ownership. The team is small (you plus two engineers) - your designs, RFCs, and roadmap input directly determine what gets built.
• Genuine depth. Database internals, distributed coordination, streaming data pipelines, and backup correctness - not CRUD apps.
• Ecosystem scope. You shape not just the managed service but the data engineering tooling around ClickHouse - ingestion, CDC, benchmarking, integrations.
• Modern tooling. Strict type checking, automated formatting, security scanning, and AI-assisted development are the norm.
• Helsinki-based, hybrid. The team is in the office regularly; you'll work closely together.

Global Benefits:

Our global benefits are designed to help you thrive and grow, personally and professionally:

• Participate in Aiven’s equity plan.
• Balance work and life with our hybrid work policy.
• Choose the equipment you need to set yourself up for success.
• Use your Professional Development Plan budget for learning opportunities.
• Receive holistic wellbeing support through our global Employee Assistance Program.
• Inquire about our Global Time Off Commitment (Parental and Sick Leave, as well as Personal Time)
• Enjoy country-specific benefits for our global cast.

Equal Opportunities:

Aiven provides equal employment opportunities to all qualified employees and applicants for employment without regard to age, gender identity, national or ethnic origin, religion, sexual orientation, physical and mental ability, marital and family status or without regard to any other similar personal attributes. Aiven complies with applicable local laws governing non-discrimination in employment in every location in which the company operates. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, transfer, leaves of absence, compensation, training and any other terms and conditions related to employment.

At Aiven we are committed to providing reasonable accommodations for qualified individuals with disabilities or special needs in our working environment and job application procedures. We make all reasonable accommodations for persons with disabilities or who otherwise need support to thrive in the workplace. We are committed to continuously improving workplace accessibility. There is an option to request a discussion in the application process but if you have any questions before applying please write to us at [e-mail].