Senior Software Engineer (Algorithms)

At Handsontable, we're all about making developers' lives easier. Our open-source product, HyperFormula, has become one of the most robust JavaScript calculation engines compatible with Excel. It’s used by dozens of companies to provide calculation capabilities for AI & LLMs, spreadsheets, and report generators.

We are looking for a Senior Software Engineer (Algorithms) with a strong algorithmic background to join the HyperFormula team. This is a critical role with a real impact on the product and the company’s direction.

If you're up for a challenge and excited to see your work powering global AI firms, join our awesome team!

🧠 You are a good match if you share our mindset

• Our mission is to enable companies to work with information using ready-to-use components.
• We envision a world where every organization can make decisions based on facts.
• Our core values are to be customer-centric, trust the team, and consistently evolve.

🚀 What You Will Be Doing

• Work on the HyperFormula project written in TypeScript.
• Build and improve the core engine: dependency tracking, recalculation strategy, performance, and correctness under real-world workloads.
• Work on graph-heavy problems: dependency graphs, topological ordering, cycle detection/handling, incremental updates, and efficient recomputation.
• Implement and optimize numerical, statistical, and matrix algorithms.
• Drive high engineering standards: testing strategy, benchmarks, profiling, and reducing technical debt.
• Maintain and develop an open-source project with an active community.
• Contribute to the long-term technical vision and architecture, ensuring scalability, performance, and security.
• Work closely with product and growth teams to align technical efforts with business goals, customer feedback, and market needs.
• Stay up to date with industry trends, new technologies, and best practices, encouraging a culture of continuous learning and improvement within the team.

🎯 About you

• You know mathematics and computer science.
• 7+ years of experience in software development in TypeScript or another programming language.
• We prioritize your ability to solve algorithmic problems over your familiarity with the syntax of TypeScript.
• Good understanding of AI and application architectures, and the software development lifecycle.
• Fluent English (C1).
• You are self-driven and proactive in solving software architecture problems.
• You are located in Poland or have citizenship of an EU country, the EEA, or Switzerland.

🙌 Nice to have

• Contributions to open-source projects.
• Experience with parsers/ASTs and interpreters/compilers.
• Continuous experience on a single project or product (2+ years).
• Strong command of software engineering workflows using AI (Claude Code, Cursor, etc.).
• Exceptional communication skills, with the ability to translate complex technical concepts to non-technical stakeholders at all levels, in both English and Polish.

🤝 What We Can Offer

• Competitive salary tailored to your experience.
• Salary of 25 000 - 35 000 PLN gross full-time contract or net B2B.
• Flexible working hours and time off.
• Private English language lessons with a native speaker during working hours.
• Work remotely, hybrid, or in our office in Gdynia.
• Training budget.
• Salary review twice a year.
• Multisport card, private medical care, and extended life insurance.
• IT equipment of your choice.
• In the office: snacks, cold beverages, weekly team lunch.
• Regular fresh-air team-building retreats.
• Work in an open environment with a unique culture of like-minded, supportive, collaborative, dynamic people focused on growth, delivery, and innovation.

At every stage of the recruitment process all applicants will be considered without regard to race, color, national origin, religion, sexual orientation, sex, age, marital or parental status, disability, veteran status, gender identity, or expression.

Recruitment process

• Submit your CV
• Meet our HR Team (45 minutes)
• You can expect a discussion about the role, company culture, team structure, and your background, experience, and successes in similar roles.
• Technical interview (1.5 hours)
• Aa deep dive into your technical expertise, your problem-solving approach, and agile ways of working.
• Culture interview with the CEO (1–2 hours)
• You will meet our CEO to discuss motivations, vision, and mutual fit.