Senior Backend Engineer (Python)
sintra.ai
Quick summary: We're looking for a backend engineer who can build Python systems that handle 50,000+ businesses running AI employees. You'll create the infrastructure that powers our agents - from handling LLM interactions to running background jobs to orchestrating workflows. All while managing large amount of business context. The challenge: writing clean, scalable code with great error handling so AI can understand failures and recover. You'll set patterns that make our backend stable and easy for the team to build on.
Why join Sintra?
We build AI employees for small businesses. Real helpers with personalities, not faceless chatbots. They handle the work that keeps owners up at night - answering customer emails, posting on social media, analyzing sales data. For business owners who've always worked alone, we're giving them their first team.
50,000+ businesses use Sintra because for the first time someone made AI actually useful for them. While Silicon Valley builds for tech companies, we're building for the florist who needs help with Instagram, the contractor drowning in invoices, the restaurant owner who can't keep up with reviews.
This is a unique moment in history. AI just became good enough to fundamentally change how small businesses operate. Behind every business is someone trying hard for their family. Someone with one goal - put food on the table. And our job is to help them succeed.
Having just raised our $17M seed round, we're off to the races. Small, fast-moving team building together in person. We ship daily, take ownership of what we build, and live by one principle - work is play.
Who we're looking for
- 4+ years building Python backend systems at scale
- Deep understanding of async programming, queues, and database design
- Experience with LLM integration and handling AI-specific edge cases
- Track record of improving entire codebases
- Comfortable using AI tools to accelerate development
What you'll do
- Build systems that let AI employees work autonomously - job queues, workflow orchestration, state management
- Implement robust error handling for non-deterministic AI behavior - retries, fallbacks, user-friendly error states
- Design database schemas and service architecture that scale
- Own major features like background task systems and automated workflows
- Create patterns and abstractions that make the backend consistent and maintainable
- Optimize performance - reduce latency, identify and fix root causes of errors
- Make our systems observable with proper tracking, logging and monitoring
- Write documentation and establish patterns that level up the entire team
Our tech stack
- Frontend: React
- Backend: Python with FastAPI, Pydantic, PostgreSQL, Celery
- Infrastructure: Railway, AWS, multiple LLM providers
- DevOps & Tooling: Github Actions, Grafana
Our hiring process
- Fill in the application form. If we see a fit, we'll reach out for an intro call.
- Complete a take-home task that mirrors real work you'd do here. Be prepared to explain what you did and why.
- Join us for a tech call. Meet the team, see if we're right for each other.
- Get an offer if it's a mutual fit.
We understand good people have options, that's why we move super fast. Life's too short for drawn-out hiring processes.
What we offer
- Compensation & Equity
Top-of-market salary in Vilnius plus meaningful equity, so you own part of what you build.
Salary range for this role: €5,000-8,000/month depending on expertise and experience. - Health & Wellness
Health insurance, gym membership with personal trainer option, team lunch at the office. - Seamless Relocation
Relocation bonus and support to make your move to Vilnius smooth.
