Senior Backend Developer

ETFbook; Polska; Remote; PLN 393,000 - 568,000; Part time

Benefits offered by this job

100% remote

Competitive B2B contract

Growth opportunities

Impactful work

Team-building events

Job summary

ETFbook is seeking a Senior Backend Software Developer to join our fully remote European team. You’ll work on cutting-edge .NET services, APIs and data-processing components that power our ETF data analytics platform.

You will design scalable architectures, optimize databases, review code and mentor junior engineers while collaborating with Product, Data and Technology teams to deliver reliable, high-quality solutions in a fast-evolving fintech environment.

Qualifications

• 8+ years of software development with strong .NET/C# experience.
• Experience with backend services, APIs and data processing.
• Knowledge of architecture and database design.
• Strong SQL skills and DB optimization.
• Experience with automated testing and deployment; Azure familiarity.
• Ability to mentor engineers and review code.

Responsibilities

• Designs and optimizes application architecture and database schemas.
• Develops and maintains the latest .NET services, APIs, and data-processing components.
• Participates in solution design and requirements analysis for major initiatives.
• Ensures backend performance, scalability, security, and reliability.
• Reviews backend code and promotes engineering standards.
• Troubleshoots complex production and system issues.
• Mentors junior and mid-level backend engineers.

Skills

C# / .NET

Backend services

APIs

Data processing

Database design

SQL optimization

Testing & CI/CD

Mentoring

English communication

Tools

Azure

Job description

Location: Remote (European Time Zone), once per month in the office in Cracow

Contract Type: B2B

About Us:

ETFBOOK is a Swiss SaaS company providing data, analytics, and custom solutions in the Exchange Traded Funds (ETFs) space. Founded in 2020, we aim to make global ETF data accessible, actionable, and valuable for institutional participants, including ETF issuers, index providers, fund service providers, market makers, exchanges, and buy-side institutions.

We develop a platform which offers comprehensive insights through a user-friendly web application and robust APIs, covering areas such as product analysis, fund flow tracking, performance comparisons, and liquidity assessments.

About the role:

We are seeking a Senior Backend Software Developer to join our fully remote team spread across Europe. You’ll join a highly skilled technology team. This team develops and maintains a cutting-edge data analytics platform using most advanced technologies to support all core business functions. You’ll be a part of a collaborative team focused on application development. This role offers the chance to make a visible impact in a dynamic, fast-evolving field.

Responsibilities:

• Designs and optimizes application architecture and database schemas.
• Develops and maintains the latest .NET services, APIs, and data-processing components.
• Participates in solution design and requirements analysis for major initiatives.
• Ensures backend performance, scalability, security, and reliability.
• Reviews backend code and promotes engineering standards.
• Troubleshoots complex production and system issues.
• Mentors junior and mid-level backend engineers.

Requirements:

• 8+ years of experience in software development with strong experience in the latest .NET/ C#.
• Strong expertise in backend services, APIs and data processing.
• Strong understanding of application architecture and database design.
• Strong SQL skills and experience with database optimization.
• Experience designing scalable, secure and reliable backend solutions.
• Experience with automated testing and deployment.
• Experience with AI-assisted development tools.Good knowledge of Azure
• Strong communication skills in English.
• Strong problem-solving skills.
• Able to work effectively with Product, Data and Technology teams.
• Able to review code and provide technical guidance.
• Able to mentor Junior and Mid-level engineers.
• Commitment to delivering high-quality solutions.

Nice to have:

• Experience with data visualization.
• Interest in financial markets, especially ETFs.
• Experience with B2B SaaS products

What we offer:

• 100% remote work from anywhere within the European time zone.
• Competitive B2B contract.
• Exciting growth opportunities in a fast-paced startup.
• Impactful work: help revolutionise ETF data market, currently fastest growing area of finance.
• Have a real impact of developing products: your work will directly influence live projects, delivering measurable results in real-world applications.
• Culture of innovation: collaborate with forward-thinking professionals in technology and finance where experimentation and creativity are encouraged.
• Team- buildings events at least twice a year, hosted in various European locations.