Staff Engineer - Fullstack JS TS

📋 Description

• • Own the full development lifecycle of high-impact features for lemlist and Taplio/Tweet Hunter, from ideation with Product to deployment in production. You will architect, code, test, and ship across React, Node.js, and MongoDB, ensuring every line you write helps 38 M ARR keep growing at 45 % YoY.
• • Drive continuous refactoring and performance tuning across a codebase that serves thousands of concurrent B2B users. Identify bottlenecks, introduce caching strategies, optimize MongoDB queries, and modernize legacy Meteor.js components to keep page load times under 1.5 s and API p99 latency under 200 ms.
• • Act as a technical mentor and multiplier for 15+ senior and mid-level engineers. Run weekly brown-bags, review pull requests with empathy and rigor, pair-program on gnarly bugs, and establish coding standards that raise overall velocity by measurable KPIs (cycle time, defect rate, PR review time).
• • Step up as Tech Lead on transversal initiatives—think multi-tenant data isolation, real-time collaboration engine, or AI-driven email personalization. You will define the technical vision, break epics into deliverable slices, coordinate cross-team dependencies, and ensure releases land on time without compromising quality.
• • Champion a culture of experimentation and data-driven decisions. Instrument features with Segment, Amplitude, and custom analytics, run A/B tests that move activation or retention by double digits, and feed learnings back into the roadmap.
• • Collaborate daily with Product, Design, and Customer Success in a remote-first, async environment. You will demo early prototypes in Loom, gather feedback in Slack threads, and iterate fast—our average time from first commit to production is <24 h.
• • Within 3 months you will have shipped at least two customer-visible features, closed 10+ high-priority bugs, and proposed one architectural improvement that was adopted by the team. You will feel at home in our GitHub, Linear, and Notion workflows.
• • Within 12 months you will have led the delivery of a major product pillar (e.g., new social-selling automation suite), improved system scalability to handle 5× current load, and become the go-to expert for at least one domain (real-time websockets, Node.js performance, or React micro-frontends). You will have mentored two engineers to promotion readiness.
• • Enjoy the freedom of a bootstrapped, founder-controlled company—no VC pressure, no politics, just focus on building what customers love and what moves the ARR needle. Your roadmap is shaped by usage data and customer calls, not by quarterly investor slides.
• • Work from anywhere in the French timezone (±2 h) with a budget to build your perfect home setup, or drop into our Paris office whenever you crave croissants and whiteboard sessions. We meet IRL once a year in a sunny location for a week of hacking, surfing, and strategy.