Backend Software Engineer (AI Squad)

Spendesk; Paris; On-site; EUR 90,000 - 130,000; Full time

Job summary

Spendesk is seeking a Backend Software Engineer (IC3) to join the AI & Data Products squad. You will design, build, and operate backend services powering AI-native features, turning predictive models and LLM outputs into production-ready capabilities integrated into spend management workflows.

You’ll collaborate with ML Engineers, PMs, and designers to deliver reliable, observable, and scalable backend systems.

Qualifications

• Significant backend software engineering experience in production environments.
• Strong track record of designing and shipping reliable backend services with measurable impact.
• Experience contributing to complex product initiatives in fast-paced, cross-functional teams.
• Exposure to ML-enabled or AI-enabled product features is a strong plus.

Responsibilities

• Design, build, and operate backend services and APIs that power AI-driven, ML-driven, or automation-heavy product capabilities.
• Translate predictive logic and AI outputs into reliable backend behaviors for user-facing flows.
• Build service layer enabling intelligent features to integrate into real workflows with latency, reliability and security in mind.
• Ensure production readiness with clear ownership of deployment, monitoring, and maintainability.

Skills

TypeScript

Node.js

APIs

Distributed systems

Observability

Kafka

PostgreSQL

SQS

Step Functions

ML integration

Tools

Kafka

SQS

Step Functions

PostgreSQL

Terraform

Kubernetes

AWS Bedrock

Job description

Build AI-powered product capabilities that automate, predict, and simplify user workflows

Spendesk is looking for a Backend Software Engineer (IC3) to join our AI & Data Products squad and help build the next generation of product features powered by AI, ML, and intelligent automation.

This is a hands-on backend role focused on turning predictive models, LLM capabilities, and business intelligence into real product experiences. You will work on backend services, APIs and MCPs that bring automation, prediction, and assisted decision-making into Spendesk’s user journeys, helping reduce manual work and make our product more proactive and intelligent.

You will collaborate closely with the 3 ML Engineers in the squad, as well as Product Managers, Designers, and applicative squads across Spendesk. Together, you will build production-grade services that expose ML-driven and LLM-driven capabilities in ways that are reliable, observable, and valuable for end users.

About the role

As a Backend Software Engineer (IC3) in the AI & Data Products squad, you will design, build, and operate backend services that power AI-native and ML-native product features.

Your mission is to help Spendesk move from isolated intelligence components to real, user-facing product capabilities. In practice, this means partnering with ML Engineers to productionize predictive logic, expose it through clean APIs and services, and integrate it into workflows that automate tasks, simplify decision-making, or anticipate user needs.

You may work on features such as:

• automated categorization and enrichment of spend-related workflows,

• predictive assistance in finance or accounting journeys,

• intelligent recommendations based on historical behavior or contextual signals,

• LLM-powered experiences that simplify user actions and reduce friction,

• backend services that make AI capabilities reusable across multiple product flows.

This role requires both strong backend engineering and genuine interest in AI-powered product design. You won't be expected to build the models yourself, but you will be responsible for making them usable, scalable, secure, and effective in production.

Our tech environment

You’ll operate in a modern engineering environment designed for both product delivery and AI integration:

• TypeScript

• Node.js for backend and banking applications

• React on the frontend

• PostgreSQL for data storage; Redis, SQS, and Kafka for jobs, queues, and event streaming

• Terraform to define infrastructure as code

• Kubernetes, Lambdas, and Step Functions to run our applications

• AWS as our cloud provider, including AWS Bedrock for LLM access

• GitHub Actions for CI

You do not need to be an ML engineer, but you must be comfortable integrating predictive or generative capabilities into backend systems and user-facing product workflows.

Key responsibilities

Backend services for AI and ML-powered product features

You will:

• Design, build, and operate backend services and APIs that power AI-driven, ML-driven, or automation-heavy product capabilities.

• Translate predictive logic and AI outputs into reliable backend behaviors that can be consumed by user-facing product flows.

• Build the service layer that allows intelligent features to be integrated into real workflows with strong standards on latency, reliability, and security.

• Ensure features are designed for production, not just experimentation, with clear ownership of deployment, monitoring, and maintainability.

Productionization of ML and LLM capabilities

You will:

• Partner closely with the squad’s ML Engineers to productionize predictive models and LLM-driven capabilities.

• Integrate model-serving APIs or LLM calls into robust backend services (your squad, or the applicative squad’s services) with proper retries, fallbacks, and observability.

• Help define evaluation and monitoring patterns that make intelligent product behaviors measurable over time.

• Contribute to the engineering patterns that allow ML and AI capabilities to be reused across multiple product features.

Automation, prediction & workflow simplification

You will:

• Build backend capabilities that help automate repetitive tasks, anticipate user needs, or simplify complex workflows.

• Work on product experiences where AI or ML can reduce manual effort, improve decision quality, or shorten time to value for users.

• Partner with Product and Design to turn ambiguous ideas into concrete backend implementations with measurable impact.

• Bring pragmatism to delivery, balancing experimentation speed with long-term maintainability and trust.

Reliability, observability & operational ownership

You will:

• Instrument services with logs, tracing, and metrics to support production visibility and continuous improvement.

• Define and uphold standards around latency, resilience, failure handling, and cost efficiency for AI-powered services.

• Build with responsible data handling, security, and privacy by default, especially when features interact with sensitive financial workflows.

• Embrace a "you build it, you run it" mindset, owning the health and quality of what you ship.

Cross-functional collaboration

You will:

• Work hand-in-hand with ML Engineers, Product Managers, and Designers to deliver AI-powered product capabilities end-to-end.

• Collaborate with applicative squads (or join them for a quarter) to integrate AI and ML services into existing user journeys and backend systems.

• Help define the technical interfaces and integration patterns that make intelligent services easier to adopt across the product.

• Share best practices in backend reliability, production readiness, and AI feature delivery across the engineering organization.

What we’re looking for

Experience & background

You have:

• Significant experience on backend software engineering experience in production environments.

• A strong track record of designing and shipping reliable backend services with measurable user or business impact.

• Experience contributing to complex product initiatives in fast-paced, cross-functional teams.

• Exposure to ML-enabled or AI-enabled product features is a strong plus.

Technical & data skills

You have:

• Strong backend engineering skills with TypeScript / Node.js or adjacent technologies.

• Experience designing APIs and service layers for complex product workflows.

• Good understanding of distributed systems, async processing, and operational reliability.

• Practical experience, or strong interest, in integrating predictive models, LLM APIs, or other AI capabilities into product backends.

• Familiarity with technologies such as Kafka, SQS, Step Functions, PostgreSQL, and modern observability practices.

Leadership & collaboration

You are:

• Highly autonomous and comfortable owning backend systems from design to production.

• Product-minded, customer-focused, and motivated by building features that create visible value for end users.

• Comfortable working closely with ML Engineers and translating their outputs into durable product capabilities.

• Pragmatic and impact-driven, able to move from experimentation to production without losing engineering rigor.

• Fluent in written and spoken English, our business language.

Nice to have:

• Experience productionizing ML-backed features such as classification, recommendation, forecasting, or automation

• Experience integrating LLM-backed capabilities into product workflows

• Familiarity with evaluation patterns for AI-powered features

• Experience in SaaS, fintech, or regulated environments

Not ticking every box? We’d still love to hear from you. At Spendesk, we value skills, potential and diverse experiences. If this role excites you and you believe you could contribute, we encourage you to apply

How we work

• AI-first, product-led: prototype fast, dogfooding, iterate based on data

• You build it, you run it: owning deployment, monitoring, and continuous improvements

• Collaboration by default: PM, Design, ML Engineering, and Backend Engineering work together toward outcomes