Senior Back-end Engineer; ML

About Toptal

Toptal is a global network of top talent in business, design, and technology that enables companies to scale their teams, on-demand. With $200+ million in annual revenue and team members based around the globe, Toptal is the world’s largest fully remote workforce.

We take the best elements of virtual teams and combine them with a support structure that encourages innovation, social interaction, and fun. We see no borders, move at a fast pace, and are never afraid to break the mold.

As a Senior Back-end Engineer for Toptal’s Core team, you will help us scale for our continued growth as a game-changing, industry-defining company shaping the future of work.

We are a product team delivering value to the end-users working closely with the business. You will be part of a collaborative team within a newly launched business unit. We’re developing advanced data and AI tools that empower companies to make smarter decisions and move faster in an increasingly intelligent world. You will have the opportunity to develop new features and improve the quality of the existing codebase.

Every bit of work you do will have a direct impact on the company’s revenue.

We don’t cut corners, and we don’t make compromises—we build expertly designed web apps that are polished, fast, well-tested, and a joy to use.

We use NextJS to render client-facing pages and to run various experiments, and Python, Supa Base, GCP and AWS power a lot of our infrastructure. While you will be primarily responsible for back-end Python, database and LMM integration work, you will have an opportunity to develop your front-end skills, so if that sounds appealing, this is the right opportunity for you.

You will also have the chance to explore new tools and frameworks, as we are always looking for ways to improve site performance and team productivity.

By joining Toptal’s Core team, you’ll work on meaningful initiatives and projects that have an impact on the bottom line of the company, with a team of highly skilled members from around the world.

This is a remote position that can be done from anywhere. Due to the remote nature of this role, we are unable to provide visa sponsorship. Resumes and communication must be submitted in English.

The following information is intended to describe the general nature and level of work being performed. It is not intended to be an exhaustive list of all duties, responsibilities, or required skills.

• Design, build and maintain outstanding, reusable, and reliable Python components.
• Design and build AI Agents, MCP servers, and data classification components for training LLMs.
• Build and extend the current SaaS Toptal Core Platform through the development of APIs and SDKs.
• Utilize generative development tools to create tests and perform AI-assisted testing of your features.
• Review colleagues’ work, provide constructive feedback, and mentor others to help the team grow and improve.
• Continuously improve team processes, share ideas, and communicate status and progress openly as a collaborative teammate.

• Begin onboarding and integration into the team, learn the Toptal Core platform and meet mentors who will support you.
• Get familiar with our product portfolio, team structure, and tech stack.
• Get familiar with our front-end and back-end architecture and all the tools we use. Learn about the processes that we follow.
• Get familiar with our CI/CD and Testing processes.

• Attend regular meetings, like technical calls, retrospectives.
• Start working on regular team tasks and become familiar with the business domain.
• Start contributing to the technical topics as well, understand the application, and general platform architecture.
• Learn and take part in the utilization of the latest LMM, AI and Agent based technologies.
• Deliver value in regular cadence.
• Get comfortable with the daily work routine of our team.
• Review code written by colleagues.
• Be ready to propose improvements to the team’s processes and codebase.

• Familiarize yourself with the team’s business domain.
• Continue to contribute to our product development.
• Design…