Senior Fullstack Engineer — Angular + .NET | Full Remote

* instinctools is a software development company that provides custom software solutions for businesses of all sizes. Our team works closely with clients to understand their specific needs and provide personalized solutions that meet their business requirements.

Our team is looking for a Senior Fullstack Engineer (Angular + C#/ .NET) for one of our clients.

The client is a fintech startup providing cutting-edge software‑as‑a‑service solutions to institutional investors. Their current offering includes advanced financial analysis, trade flow, and portfolio management solutions.

This role will be primarily responsible for designing, developing, and maintaining backend services, APIs, and data pipelines, while collaborating closely with frontend engineers to support performant, reliable user experiences. The ideal candidate brings strong system design instincts, experience working with data‑intensive applications, and the ability to translate sophisticated financial and operational requirements into secure, scalable, and high‑performance solutions.

• Experience in C#/.NET (ASP.NET Core)
• Experience in Angular
• Expertise in SOLID principles and commonly used design patterns
• Working knowledge of relational databases
• Attention to good UI/UX design
• Ability to work in agile‑based project management structure
• Familiarity with Git

• Design, build, and maintain backend services, APIs, and core application logic that power user‑facing applications.
• Own and evolve system architecture with an emphasis on scalability, security, reliability, and performance across both backend and frontend components.
• Collaborate closely with product managers, frontend engineers, backend engineers, and cross‑functional teams to translate business requirements into end‑to‑end technical solutions.
• Build and maintain data pipelines, integrations, and communication layers between internal and external systems.
• Implement and review automated unit, integration, and end‑to‑end tests across backend and frontend codebases to ensure quality and stability.
• Troubleshoot and resolve production issues across the stack, optimize performance, and proactively identify potential technical risks.
• Participate in architectural design discussions, code reviews, and contribute to maintaining high‑quality technical documentation.
• Support the full lifecycle of feature delivery – from initial design to implementation, deployment, and post‑release monitoring.
• Self‑starter who is passionate about technology
• Keen eye for automation and improving efficiency
• Ability to provide leadership and accountability for work they undertake
• Takes ownership of their work and has exceptional attention to detail
• Has excellent communication skills and the ability to articulate their thoughts and ideas
• Comfortable with fast‑paced and strongly collaborative environments
• Able to take on ideas and feedback from both technical experts and business thought‑leaders.

• flexible working time (overlap with New York time is important)
• professional and ambitious team
• transparent system of professional and career development
• a pleasant financial motivation depending on goals
• learning opportunities, seminars and conferences and time for exploring new technologies
• the opportunity to realize your potential outside the projects: we arrange meetups and conferences where our staff can perform, develop professional communities
• full remote work
• partial compensation of medical insurance (Luxmed) and multisport card
• co‑funding for language courses (Polish and English)

Join us and be part of a team that is changing the world through technology.