Senior Backend Developer (M/F)

Roundtable; Paris; Hybride; EUR 75 000 - 90 000; Plein temps

Avantages offerts par ce poste

Alan health insurance

Swile restaurant card

25 days holidays + RTT

MacBook

Résumé du poste

Roundtable is building the gold standard for private equity by shipping a highly type-safe, scalable stack in a hybrid Paris/Toulouse setup. You will join a senior 10-engineer team, shaping domain-driven fintech workflows and production reliability under founders CTO and CPO guidance.

You’ll own critical features from zero-loss ownership tracking to auditable atomic transitions, with a focus on performance, safety, and business impact. Expect a fast-moving, high-ownership environment.

Qualifications

• 5+ years in Node.js/TypeScript or equivalent.
• Strong understanding of fintech domains and precision.
• Ability to write readable, maintainable code with clear boundaries.
• Experience with scalable architecture and production-grade systems.

Responsabilités

• Zero-Loss Engineering: evolve Cap Table engine with exact precision.
• Design atomic financial workflows with auditable state changes.
• Architect for scale to handle 10x volume with type safety.
• Own reliability stack including observability and AI-assisted pipelines.

Connaissances

Node.js/TypeScript

Fintech domain

Precision mindset

Domain-driven design

Observability

Outils

PostgreSQL

Prisma

Redis

BullMQ

tRPC

Zod

OpenTelemetry

Datadog

Description du poste

The Challenge: Building the “Gold Standard” for Private Equity

Private Equity is the last frontier of finance still running on Excel and fragmented processes. At Roundtable, we are building the infrastructure that allows thousands of investors to co-invest with surgical precision.

You’ll join a 10 engineer senior full-stack team organized in 2 squads, and you’ll be part of opening a third one. You’ll work closely with 2 product managers and be directly supported by our CTO and CPO, both founders.

Your Mission

You won’t just be “coding features.” You will be solving domain-driven puzzles where errors aren’t an option:

• Zero-Loss Engineering: Evolve our Cap Table engine to track ownership across thousands of investors with absolute precision (no rounding errors, no “lost cents”).

• Atomic Financial Workflows : Design atomic transitions for complex, multi-jurisdiction financial operations. Every state change must be auditable and reversible.

• Architecting for Scale: Help us transition our domain-driven architecture to handle 10x the current volume while maintaining 100% type safety.

• Production-Grade Engineering: Own the full reliability stack, from distributed tracing and structured observability to AI-assisted document pipelines. You’ll work on systems where understanding what happens in production is as important as what happens in code

Core Stack

• Core: Node.js, 100% TypeScript (Strict mode, no any).

• Data: PostgreSQL + Prisma, Redis (BullMQ for critical job queues).

• API & Communication: tRPC (with Zod) for end-to-end type safety from the database to the frontend.

• Ops: GCP, Turborepo, OpenTelemetry, Datadog.

• Quality: Vitest, Playwright, Zod (runtime validation at all boundaries).

You are a great match if:

Experience: 5+ years in Node.js/TypeScript. You’ve ideally seen a startup growPrecision Mindset: You understand that in fintech, a bug isn’t just a ticket; it’s a financial consequence. You care about decimal precision and idempotency.Pragmatic Architecture: We don’t follow a named architecture style. We structure our code around business logic, clear entry points, explicit boundaries, and readability by anyone on the team. We care about code that makes sense, not code that follows a manifesto.Product-Minded Engineering: You don’t just “write tickets.” You understand the business logic behind the code and take ownership of the features you build. You enjoy collaborating with product stakeholders to ensure the technical solution perfectly serves the user experience.Domain Curiosity: A background in finance or fintech is a plus, but not a requirement. Private equity has its own logic and vocabulary; we’ll teach you the domain. What matters is that you’re genuinely curious about how it works.

What we offer

High-Growth Environment: A front-row seat in a startup shaping the future of private equity. Ranked #14 in the Sifted 250, Europe’s fastest-growing startups by revenue. Today: €500M+ in assets under administration, 25,000+ investors, and 450+ investment clubs across 100+ nationalities.Tech Excellence: A culture that values quality over quick fixes. We invest in a type-safe, well-structured codebase and modern developer experience, because good engineering compounds over time.AI-Augmented Engineering: AI is embedded in how we work, from development workflows to product features. It makes us faster. But ownership stays human: every engineer understands, owns, and stands behind every line that goes to production. AI is a tool, not a crutch.Flexibility & CultureHybrid Work: Beautiful offices in Paris or Toulouse. 2 to 3 days remote per week.Ambitious Peers: Work with a high-caliber team driven by excellence and continuous learning.Benefits & PerksCompensation: Competitive salary (75-90K) + Employee Stock Options Plan.Health & Well-being: Alan insurance (50% covered) and Swile restaurant card (€10/day).Time Off: 25 days of holidays + RTT.Sustainable Commute: €600/year “Forfait Mobilité Douce” for eco-friendly transportation.Gear: High-end MacBook as your standard working tool.