Senior AI Backend Engineer - France and Poland

LumApps•Webster, MA

12d•Hybrid

About The Position

LumApps is an AI-powered Employee Hub that helps companies with their digital transformation in communication, collaboration, and engagement. The company is a leader in the Employee Experience Platform market, recognized by Gartner and Forrester, and part of the French Tech Next40/120 program. In 2025, LumApps partnered with Beekeeper to expand its reach to all types of workers. LumApps' mission is to make people feel they belong and have a purpose, fostering an environment where employees are engaged and work towards common goals. Over 700 companies use LumApps to improve team productivity with its AI-powered platform integrated with Google and Microsoft suites, transform employees into ambassadors, make them more efficient and connected, reduce turnover, accelerate onboarding, improve collaboration, and enhance customer experiences. With over 600 employees across 11 offices globally, LumApps is undergoing an ambitious growth phase under new shareholder Bridgepoint to become the market leader. The company values include 'be bold, do amazing things', 'say what you mean, do what you say', 'one team, same mission', and 'always be evolving'.

Requirements

3–5 years of professional backend experience.
Solid Python skills.
Strong grasp of Clean Architecture and SOLID principles.
Comfortable navigating a large monorepo.
Confident writing well-tested, maintainable code at scale.
Hands-on experience — or a strong curiosity — with agent orchestration frameworks like Google ADK or AWS Strands, RAG architectures, and LLM providers such as Google Gemini running on Vertex AI and Mistral.
Understand how to build stateful multi-agent systems.
Comfortable with real-time streaming patterns (SSE, AG-UI protocol).
Understand the systems you touch — Flask for HTTP APIs, SQLAlchemy + Alembic for data modeling and migrations, Redis for caching and session management, PostgreSQL with multi-tenant schema partitioning, Pub/Sub for event-driven flows, and GCS for file storage.
Know how to deploy to GCP and understand production monitoring via OpenTelemetry and Langfuse.
Write tests with confidence — unit tests that cover business logic, component tests that validate the HTTP layer against a real database.
Know the difference between testing for coverage and testing for confidence, and actively raise the bar for the team.
Can express complicated issues simply.
Write clear design documents, participate actively in design reviews, and flag risks early.
Communicate in English fluently across engineering, product, and stakeholder audiences.
Consider security implications when designing systems — particularly around multi-tenancy, API access, and LLM input/output boundaries.
Proactively seek review on security-sensitive changes.
Give direct, constructive feedback in code reviews and mentoring.
Seek to understand other points of view and contribute to a team culture grounded in psychological safety and technical excellence.

Nice To Haves

Experience with conversational agents and agentic workflows.
Experience with RAG pipelines and multi-agent orchestration.
Experience with real-time streaming infrastructure.
Experience with the Agent Engine, RAG & Knowledge Retrieval, Agent Studio Backend, or Observability components of the AI Agents Platform.

Responsibilities

Independently scope and implement solutions for your team's projects.
Make well-reasoned design decisions, identify tradeoffs and risks, and select the appropriate level of abstraction.
Handle open-ended problems and ambiguity well, and ship frequently to mitigate risk.
Estimate rigorously based on iterative learning, and hold yourself accountable end-to-end — through planning, deployment, maintenance, and monitoring.
Communicate technical issues and decisions clearly and proactively to a cross-functional audience — including product, design, and other engineering teams.
Share bad news quickly.
Engage in productive dialog even when there are conflicting views, and ensure critical systems are documented.
Write meaningful code reviews that raise the bar for the whole team.
Proactively identify and help resolve problems that impact your team.
Design with security in mind and seek reviews on security-sensitive areas.
Use KPIs and a strong product understanding to inform decisions and measure impact.
Mentor junior engineers on technical subjects.
Lead and coach within your team where trusted.
Elevate testing practices.
Broaden your impact by considering the effects of your work on adjacent teams, and help drive hiring by reviewing technical tests and conducting technical interviews.