Head of Product Engineering

Kolet; Paris; On-site; EUR 140,000 - 190,000; Full time

Job summary

Kolet is seeking a Head of Engineering to own product-driven technology decisions and lead a small AI-native team. You will partner with the CEO to turn business priorities into technical outcomes, balancing speed, quality and scope while staying hands-on.

You will build, ship, and prove impact on activation, conversion, partner integrations, and ops. This role offers a clear growth path toward CTO as Kolet scales.

Qualifications

• Experience leading or mentoring engineers and owning features from problem to impact.
• Strong full-stack TS with real backend depth and third-party API integrations.
• Experience handling production incidents in early-stage environments.
• Ability to translate business priorities into a concise project roadmap.

Responsibilities

• Start from the problem, challenge the ask before coding.
• Own the end-to-end solution and measure impact on the product metrics.
• Ship first version in days and iterate quickly.
• Build full-stack with a strong backend backbone and integrations.
• Be the founders' single tech contact and arbitrate trade-offs early.
• Lead the team and grow engineers into product engineers.
• Make AI an everyday tool to accelerate delivery (code, UI, tests).
• Keep production healthy with CI/CD, monitoring and incident response.
• Own quality and QA across code and the team’s work.

Skills

Full-stack TypeScript

Backend depth

Node.js

PostgreSQL

GCP / CI/CD / containers

Security (OAuth, JWT)

AI-native

Product & UX sense

Tools

NestJS

React Native

Next.js

Job description

We’re looking for a Head of Engineering: part builder, part product thinker, and the go‑to tech person for the founding team. We won’t hand you specs to code. We’ll hand you Kolet’s real problems (activation, conversion, partner integrations, ops pain...) and trust you to figure out what to build, ship it, and prove it worked. You’ll report to the CEO, lead a small AI-native team, and still spend most of your time building. This isn’t a CTO role on day one. But the ambition is real: prove your impact, grow the team, and you’ll have every opportunity to become Kolet’s CTO as we scale.

Missions

• Start from the problem, not the ticket. Sit with the team, dig into what’s really broken, and challenge the ask before writing a single line of code.

• Own the full loop: understand the problem → design a simple solution → build it end to end → ship it → check it’s used and actually moves the needle. Then iterate, simplify, or kill it.

• Cut scope like a pro: get a first version into users’ hands in days, not quarters.

• Build full-stack, with a strong backend backbone: platform, telecom integrations and core business logic, plus web and mobile whenever the problem calls for it. Most of your time stays hands-on.

• Be the founders’ single tech point of contact: turn business priorities into a short list of projects, arbitrate between impact, speed, quality and complexity, and flag trade‑offs early and in plain words.

• Lead the team: organize who works on what, grow our two engineers (1 senior / 1 junior) into product engineers who own problems end to end, and help hire the next ones.

• Make AI our unfair advantage: use it every day to ship faster (code, UI from our design system, tests), and spot where it can solve real problems for other teams at Kolet.

• Keep prod healthy: CI/CD, monitoring, alerting, incident response. On this team, everyone looks at prod and feels responsible for it.

• Own quality & QA: test your own code and your team’s (unit, integration, end-to-end on critical flows like purchase and eSIM activation), run code reviews, and set the quality bar so we ship fast without breaking things for our travelers. There’s no separate QA team: quality is 100% on you, for your code and your team’s. It’s part of the job, not an afterthought.

How we work

• Daily stand-up: a quick sync to unblock each other and get back to building.

• 2-week sprints: clear priorities, a focused scope, and real room to ship.

• Sprint demo every 2 weeks: we show what we actually shipped to the whole team. Working product, not slides.

• Monthly retro: what worked, what didn’t, what we change next.

• You own your data: every engineer has their own dashboards to track how their features perform. Ship it, watch it, improve it.

Our stack

• Mobile: React Native, with CD via Expo Application Services (EAS) - auto-deploy to stores + preview builds on every PR

• Mobile state & data: Zustand (state management), React Query (backend calls)

• Frontend: React, deployed on Vercel

• Backend: Node.js / TypeScript, NestJS

• Database: PostgreSQL

• Cache: Redis

• Cloud & Infra: Google Cloud Platform (GCP), CI/CD, containerization

• Security: OAuth, JWT lifecycle, secret management, access control, encryption

• Telecom integrations: eSIM provisioning providers, roaming partners, multi‑IMSI logic, event handling

• Architecture patterns: Distributed systems, async / event-driven workflows

We care less about ticking every box and more about your curiosity, learning speed, and potential to grow. If your path isn’t an obvious match on paper, tell us why you can grow into the role. We know that perfect candidates don’t exist. Even if not all of this applies to you, we’d love to learn more about you.

Experience

• Experience6+ years building and shipping products in production, ideally in startups or scale-ups where tech served the business.

• Experience leading or mentoring engineers: tech lead, lead dev, or de facto owner of a product area.

• A track record of owning features from problem to impact: you can tell us what you built, why, and what it changed for users or revenue.

• Full-stack TypeScript, with real backend depth and third-party API integrations in complex domains (telecom, payments, infra-heavy environments).

• You’ve handled production incidents and know what “good enough” looks like at an early stage.

Skills

• Sharp business sense: you quickly get what really matters for Kolet, ask the right questions, and push back on the need when it makes sense.

• Crystal-clear communication: code is a language, and so is talking to Ops, Growth or a partner. You understand precisely what’s being asked and explain trade‑offs simply.

• AI-native: AI coding tools are part of how you build, design UI and test. Every single day.

• Solid technical foundations: Node.js architecture, PostgreSQL, secure systems (OAuth, JWT lifecycle, secret management), GCP / CI/CD / containers, async and event-driven workflows.

• Product & UX sense: you can ship a clean interface from a design system without waiting for a pixel-perfect mockup.

• Comfortable mentoring engineers and giving structured, constructive feedback.

• Bonus / Nice-to-haveExperience with NestJS, ReactNative or Next.js.