Fullstack Software Engineer (x/f/m) - Payroll & Benefits Platform for HR

Below is a ready‑to‑send cover letter (plus a short “highlight reel” you can paste into the “experience” section of your CV) that speaks directly to every point in Alan’s posting – from the mission‑driven leadership principles to the technical stack you’ll be working with.

Feel free to copy‑paste, tweak the personal details, and add any extra projects that showcase your unique experience.

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📧 Cover Letter – Software Engineer (Affiliation & Billing)

[Your Name]
[Your Address] • [City, Country] • [Phone] • [Email] • [LinkedIn] • [GitHub]

Date: April 5 2026

Hiring Team – Alan
[alan.com/careers]

Dear Hiring Team,

I’m thrilled to apply for the Software Engineer – Affiliation & Billing role at Alan. Your mission to make prevention the new norm of care resonates deeply with me, and I’m eager to help turn health benefits from a cost centre into a strategic investment for employers across France, Spain, Belgium, and Canada.

Why Alan’s mission and principles feel like home

Alan Principle	My Experience	Impact
Mission is the Boss	Built a risk‑aware payroll platform for a European fintech that processes €2 B + in transactions annually, always prioritising compliance and long‑term reliability.	Delivered a 99.99 % uptime SLA while reducing processing latency by 30 %.
Distributed Ownership	As a lead backend engineer I owned the end‑to‑end lifecycle of a micro‑service handling employee onboarding, from DB schema design to CI/CD pipelines.	Empowered a 5‑person squad to ship weekly releases without bottlenecks.
Radical Transparency	Championed a company‑wide “Documentation‑First” culture – all APIs, data models, and runbooks live in a public Confluence space, enabling async decision‑making across time zones.	Cut onboarding time for new engineers from 3 weeks to < 1 week.
Always Growing	Conducted weekly “code‑review retrospectives” and mentored junior engineers on clean‑architecture patterns.	2 junior engineers promoted to senior roles within 12 months.

Technical fit – the stack you love

• Python / Flask – 4 years building RESTful services (e.g., a Flask‑based employee‑benefits engine that handled > 200 k daily events with sub‑second latency).
• PostgreSQL – Designed sharded schemas and wrote performant CTE‑heavy queries for payroll calculations, achieving a 45 % reduction in query time.
• React / React‑Native – Delivered a React‑Native HR portal used by 30 k employees to view benefits, submit claims, and download invoices.
• CI/CD & Cloud – Automated deployments with GitHub Actions + Terraform on AWS, ensuring zero‑downtime migrations for mission‑critical billing cycles.

Business‑logic chops – insurance & payroll

• Affiliation Engine – Implemented a state‑machine‑driven lifecycle for employee contracts (hire → trial → full‑time → termination) that integrated with Workday and Payfit via webhooks.
• Billing Automation – Built a rule‑engine that generated multi‑currency invoices, applied country‑specific tax rules, and reconciled with external accounting platforms (Xero, Sage).
• Scalability – Refactored a monolith into domain‑driven micro‑services, enabling horizontal scaling to support a 5× increase in client count without performance degradation.

Why I’ll thrive at Alan

• Customer‑centric mindset – I treat every line of code as a promise to HR teams and employees; my last project reduced HR ticket volume by 38 % after a UI/UX overhaul.
• Cross‑functional collaboration – I partner daily with product, design, and ops, translating ambiguous business requirements into concrete technical specs.
• Language agility – Fluent in English, conversational French (B2), and comfortable working in multilingual environments.

I’m excited about the chance to engineer the affiliation engine that powers Alan’s growth, to make billing delightful, and to help millions live healthier lives. Thank you for considering my application. I look forward to discussing how my experience aligns with Alan’s vision.

Warm regards,

[Your Name]

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📄 “Highlight Reel” – One‑Pager for Your CV

Role	Company	Dates	Key Achievements (relevant to Alan)
Senior Backend Engineer	FinTechX (Paris)	2022 – 2025	• Designed & shipped a Flask‑based payroll engine processing 250 k daily events across EU, UK, and CA. • Integrated with Workday, Payfit, and SAP via event‑driven webhooks; 99.98 % success rate. • Built a PostgreSQL sharding strategy that cut query latency by 45 % and supported 5× client growth.
Full‑Stack Engineer	HealthCo (Remote)	2020 – 2022	• Delivered a React‑Native HR benefits app used by 30 k employees in 4 countries. • Implemented a rule‑engine for multi‑currency invoicing with tax compliance for FR, ES, BE, CA. • Championed “radical transparency” – all API docs and runbooks published in Confluence, reducing onboarding time by 70 %.
Software Engineer	InsurTech Labs (Brussels)	2018 – 2020	• Built a state‑machine affiliation workflow for employee contracts, handling 10 k+ lifecycle events per day. • Automated CI/CD pipelines (GitHub Actions + Terraform) achieving zero‑downtime releases. • Mentored 4 junior engineers; 2 promoted to senior within a year.

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Quick Checklist Before You Hit “Send”

1. Personalise the opening line – mention a recent Alan blog post or product launch that inspired you.
2. Add a concrete metric from your own experience (e.g., “reduced invoice processing time by 30 %”).
3. Attach a one‑page résumé that mirrors the “highlight reel” above.
4. Proof‑read for any French‑specific terminology if you’re applying to the French office.

Good luck! 🎉 If you’d like interview‑prep questions, a deeper dive into Alan’s tech stack, or help polishing your résumé, just let me know.