Preply

Senior ML Platform Engineer (Agentic Platform)

Preply
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22 hours ago
Barcelona, SpainSenior

Responsibilities

  • Build a durable agent runtime with checkpoints, retries, timeouts, resumability, and deterministic recovery where possible.
  • Create a secure tool layer for discovery, registration, invocation, and versioning across internal APIs and external services, including MCP where useful.
  • Own agent state, context, and memory primitives with lifecycle, privacy, retention, and retrieval semantics.
  • Design identity, scoped permissions, authorization, approvals, escalation, and handoffs for agent systems.
  • Develop guardrails for tool access, policy enforcement, argument validation, sandboxing, and action limits.
  • Provide observability, trace replay, and scenario-based evaluation across plans, model calls, tool calls, state transitions, and outcomes.
  • Ship SDKs, templates, local tools, documentation, and paved-road patterns for agent development.
  • Evaluate frameworks, workflow engines, and tool protocols while operating the platform with SLOs, capacity and cost controls, incident response, and operational standards.
  • Partner with Applied Science, Data, Product, Security, and Engineering teams to shape platform architecture and technical direction.
  • Participate in a paid on-call rotation.

Requirements

  • At least 5 years of experience designing, building, and operating backend services or ML infrastructure handling production traffic.
  • Strong Python skills and experience building developer-facing APIs, SDKs, or shared libraries.
  • Experience building GenAI-powered or agentic systems using tool or function calling, structured outputs, and multi-step workflows.
  • Hands-on experience integrating production services through APIs and events, including authentication, authorization, and secure service-to-service interaction.
  • Experience with at least one major public cloud and its services and infrastructure, preferably AWS.
  • Hands-on experience with distributed tracing, system telemetry, SLOs, and incident triage.
  • Strong communication skills and at least C1 English proficiency.
  • Experience using AI thoughtfully in engineering workflows, including setting quality gates and safety nets and influencing architecture, business logic, and security decisions.
  • Preferred experience with LangGraph, OpenAI Agents SDK, or Temporal.
  • Preferred experience with agent evaluation, simulation, or production feedback loops.
  • Preferred experience designing sandboxed execution environments and delegated authorization for autonomous systems.
  • Preferred hands-on experience with MCP Gateway.
  • Familiarity with GenAI observability, model gateways, and the boundary between shared GenAI platforms and agent runtimes.

Benefits

  • Open, collaborative, dynamic, and diverse company culture.
  • Monthly allowance for Preply lessons, a Learning & Development budget, and time off for self-development.
  • Competitive financial package with equity, leave allowance, and health insurance.
  • Attractive relocation package for joining the Preply Barcelona Hub when relocating from outside Barcelona.
  • Access to free mental health support platforms.
  • Access to Gympass-partnered wellness and gym centers throughout Spain.
  • Opportunity to support learners and tutors in 175 countries and counting.

Tech Stack

Preply

About Preply

10,000+ employees

Preply builds an online marketplace that connects learners with human tutors for live language lessons, supported by AI tools. Consumers book 1:1 sessions and ongoing courses, while organizations use Preply Business for corporate language training; revenue comes from commissions and subscriptions. Founded in 2012 and privately held, Preply operates globally with 100,000+ tutors teaching 90+ languages.

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