Senior Software Engineer

Who We Are We've proudly been featured on Inc's 500 Fastest Growing Companies in America for 4 years in a row in the U.S. BigTime Software is the engine behind the greatest consulting firms on the planet, delivering back-office, time/budgeting and invoicing to over 2,500 firms worldwide and tracking over $4 billion in billable time each year. Our flagship product is a SaaS-based system that is custom-built for the professional services industry. BigTime's headquarters is in Chicago, with offices in Chicago, Boston, Phoenix, and Wrocław. We've proudly been named the Best Places to Work for 3 years in a row. We are looking to add a dynamic Senior Software Enginee r to our development team. The individual in this role will collaborate extensively to design, build, and test functionality in our core system. The ideal candidate will be passionate about development and able to solve difficult technical problems in a fast-paced, agile environment. What You'll Be Doing? We're looking for someone to drive the Polish development team to focus on .NET services and help us scale the platform, ensuring quality, performance, and security, while collaborating with the team in U.S. Key responsibilities: Design, implement, and test new features in a cloud SaaS system (.NET Core / C#, React, TypeScript). Work with databases: schema modeling, queries/stored procedures, and performance tuning (SQL Server or other). Quality assurance: unit and integration tests, code reviews, maintaining "Definition of Done" standards. Performance & scalability: bottleneck analysis, profiling, optimizations, and designing for growth resilience. Security: security-by-design (authentication/authorization, OWASP), safeguarding data in production. End-to-end ownership of initiatives/projects in an agile setup (planning, estimation, delivering increments, collaboration with Product/UX). Collaboration with technical and non-technical stakeholders; translating business requirements into technical solutions. Who You Are: 5 years of professional experience working with a .NET tech stack. Has a solid understanding of the .NET Core, C# programming language, React, and Typescript. Deep understanding of database design and development using SQL Server or other database systems. Able to lead projects and mentor others developers. Has experience with performance optimization, scalability, and security. Has a strong understanding of software design patterns and principles. Able to effectively communicate with stakeholders, including non-technical stakeholders. What We Offer: Flexible contract type (Contract of employment or B2B) . Hybrid work model. Private healthcare . MyBenefit system ️. Multisport cards ️. Modern office in the center of Wrocław. Unlimited drinks and snacks in the office . Why Join Us? Impact - Your input will be important in making architectural decisions, driving innovation and new ideas, and you'll see the direct impact of your work in production. Mastery - Hone your craft in ASP.NET Core, AWS, SQL Server, React/TypeScript. We run code reviews, feature flags, monitoring/observability, and blameless post-mortems. Purpose - Your code powers a SaaS for Professional Services used by 2,500 firms, tracking $4B in billable time each year. It's mission-critical software with real impact on customer revenue, scale, and reliability and you'll be at the center of it. Perks you'll actually feel - Consistent growth (Inc. 500 - 4×; Crain's Best Places to Work - 3×), a modern office in Wrocław, teams in the US and Poland, a friendly culture, and room for initiative. Ready to make an impact? Apply now