Middle/Senior Full-Stack Engineer (React + Python)

About the Position

We are seeking a talented Middle/Senior Full-Stack Engineer (React + Python) to join our dynamic team in Ukraine for a defense domain project.

Referral bonus: $800

What is this project about?

An AI-powered analytics platform built for the defense domain. It ingests and analyzes data from multiple sources, automatically surfacing key findings and generating actionable insights and recommendations. By automating heavy manual analysis, the platform helps organizations make faster, better-informed decisions, reduce manual effort, and improve overall operational performance.

Responsibilities

• Develop and maintain full-stack features using React and Python.
• Build complex interactive user interfaces for data exploration, analytics, and operational workflows.
• Build conversational agent interfaces supporting free-form requests, clarification questions, plan review and approval, streaming execution progress, cancellation, and result presentation.
• Develop data exploration interfaces for keyword, structured, spatial, temporal, and semantic search.
• Build advanced data grids with multi-select filters, filter chips, sorting, pagination, virtualization, object preview, and detail panels.
• Integrate RESTful HTTP APIs and SSE streams for search, ingestion, agent execution, report generation, audit, and data-management workflows.
• Design and implement backend APIs and business logic using Python and FastAPI.
• Implement backend services for data ingestion, processing, validation, transformation, and enrichment.
• Build integrations between frontend, backend, AI/ML services, and external systems.
• Implement asynchronous processing, background jobs, task execution, and long-running workflows.
• Develop resilient SSE-based updates for long-running operations, including reconnect, state reconciliation, error handling, and cancellation states.
• Implement advanced geospatial visualization features using MapLibre GL JS.
• Develop interactive map components, layers, markers, clustering, drawing tools, and geospatial controls.
• Implement document, image, video, audio, structured-data, and geospatial preview experiences.
• Visualize structured AI-generated insights, recommendations, and analytical results.
• Work with databases and implement efficient data access and processing logic.
• Optimize both frontend rendering and backend services for performance, scalability, and reliability.
• Implement reusable UI components and maintain a scalable full-stack architecture.
• Participate in technical design, estimation, refinement, and code reviews.
• Write unit, integration, API, and end-to-end tests where appropriate.
• Debug production issues across the frontend and backend and contribute to root-cause analysis.
• Collaborate closely with the Architect, ML Engineers, DevOps, QA, UI/UX Designer, BA, and Product Owner.
• Maintain frontend and backend documentation, architectural decisions, API contracts, component guidelines, and implementation standards.

Requirements

• Hard skills

  • 4+ years of experience in software development, with strong experience across both frontend and backend.
  • Strong experience with React, TypeScript, and modern frontend architecture.
  • Solid knowledge of JavaScript (ES6+), HTML5, and CSS3.
  • Strong experience with Python and modern backend frameworks, preferably FastAPI.
  • Experience building complex, data-intensive web applications.
  • Experience designing and consuming RESTful HTTP APIs and Server-Sent Events (SSE), including streaming updates and long-running operation progress.
  • Experience building backend APIs, business logic, integrations, background jobs, and data processing services.
  • Strong understanding of state management (Redux Toolkit, Zustand, Context API, or similar).
  • Experience with MapLibre GL JS (or Mapbox GL JS) for building interactive geospatial applications.
  • Understanding of map projections, coordinate systems (WGS84, Web Mercator), MGRS, and geospatial concepts.
  • Experience working with geospatial data formats and representations, including GeoJSON polygons, vector tiles, raster layers, markers, clustering, and drawing tools.
  • Experience implementing map-based search using points, radius, bounding boxes, polygons, and area-of-interest intersection.
  • Experience building advanced data grids with structured filters, sorting, pagination, virtualization, saved views, and synchronized table/map selection.
  • Experience building conversational or workflow-driven interfaces with streaming responses, approval steps, human-in-the-loop interactions, citations, attachments, and execution states.
  • Experience with FastAPI-based backend services.
  • Experience with asynchronous processing, background tasks, queues, or long-running workflows.
  • Understanding of databases and data modeling, with practical experience working with SQL databases.
  • Experience integrating frontend and backend components with AI/ML services and external systems.
  • Understanding of authentication flows, OIDC/OAuth 2.0 with PKCE, session handling, RBAC, and secure application practices.
  • Understanding of frontend and backend performance optimization.
  • Experience with component-driven frontend architecture and reusable UI systems.
  • Ability to write clean, maintainable, testable, and well-structured code across the full stack.
  • High level of ownership, proactivity, and engineering discipline.
  • Intermediate + level of English.

• Nice to have

  • Experience with AI-powered applications or data visualization platforms.
  • Experience building intelligence, defense, geospatial, or operational data applications.
  • Experience with large data grids, map-heavy applications, or document and provenance viewers.
  • Experience with FastAPI-based backend services and Backend-for-Frontend patterns.
  • Experience with async Python frameworks, background workers, queues, or workflow orchestration.
  • Experience with PostgreSQL, PostGIS, Redis, or similar technologies.
  • Familiarity with Docker and CI/CD pipelines.
  • Experience working with real-time or streaming data.

We Offer

Work vibe

• Flexible full-time/part-time hours
• No micromanagement-time logging is for accounting only
• High-quality equipment (MacBook or your own device)
• Dynamic, low-bureaucracy environment
• Team events, swag, and a great crew to hang with

Holidays and leaves

• 20 days of paid annual vacation;
• 15 days of paid sick leaves;
• Possibility to use vacation during probation;
• Maternity and paternity leave;
• Days off on all government holidays.

Education

• $100 annual education allowance
• Mentorship program-learn or lead
• English lessons with biannual reviews
• Certification cost reimbursement
• Free access to Udemy courses on request

Perks

• Social package: medical insurance, sports compensation, or psychological training
• IT Club Loyalty card (Lviv IT Cluster)
• No overtime-work-life balance matters
• Transparent payments in EUR/USD, on time every month
• Assistance with military reservation procedure

About the Company

More details in our telegram. Check all positions: here.