Freelancer profile translated to English.

Description

Hello!

I'm Nicolas Daudin, a Senior Backend Engineer in Node.js / TypeScript / AWS, AI-augmented, with 12 years of experience. I help SMEs, startups, IT consulting firms, and large corporations deliver and stabilize their web applications, APIs, back-offices, and SaaS solutions, quickly and cleanly.

🎯 Some achievements

– Multi-PSP Payment Platform (AWS serverless microservices): +5% success rate, 3x risk ratio reduction

– SaaS + Chrome Extension (20,000+ freelancers): UI/UX redesign V1→V2 (−25% tickets), migration of 2 APIs to NestJS, repository of 7,000+ skills

– 3x accelerated delivery thanks to an AI-augmented workflow (Claude Code)

– Web entrepreneur: 250+ articles, 10 million visits

🧑‍💻 What I can do for you

– Custom web applications, SaaS, back-offices, and business software

– REST APIs (Express / NestJS): design, integration, delivery

– Cloud architecture & serverless microservices (AWS: Lambda, Amplify Gen 2, DynamoDB, SQS)

– Migrations & redesigns: API, UI/UX, version upgrades

– Chrome extensions, scripts & web scraping (Puppeteer, Playwright)

– Project takeover, corrective and evolutive maintenance

🛠️ My stack

Node.js, TypeScript, AWS (Lambda, Amplify Gen 2, DynamoDB, SQS), NestJS, Express, React, Next.js, Redux, PostgreSQL, Prisma, MongoDB, Stripe, Auth0, Docker.

🤖 AI-Augmented Developer

I use AI (Claude Code) throughout the development cycle (from design to review) to deliver faster without sacrificing quality. And beyond code: I also automate my tools (Slack, Notion, Excel…). Always on solid foundations: TDD, Clean Architecture, CI/CD.

🤝 How I work

Proactive, solution-oriented, reliable, autonomous, and transparent. I meet deadlines and do everything possible to reduce technical debt, or at least not worsen it. Fully remote, international contexts, open to occasional travel.

⏩ What's next?

Have a project in mind? Contact me, let's discuss it over a virtual coffee!

Industry field of expertise

Languages

French
Native or bilingual
Spanish
Native or bilingual
English
Fluent

Workplace preferences

Can work on-site

Paris (up to 50km), Toulouse (up to 20km), Lyon (up to 20km), Montpellier (up to 20km), Bordeaux (up to 20km)

SGW Payment
Fullstack Developer Node.js, AWS, and TypeScript
BANKING AND INSURANCE
January 2025 - Today (1 year and 7 months)
Paris, France
Technical lead for SGW's fintech payment platform (white-label, multi-PSP): ~7,000 payments/day, about ten merchants, several million € in volume/year.

Beyond PSP integration, I develop the features required by payment complexity (pre-authorization & capture, multi-PSP cascading, retries, subscriptions), in a highly iterative and data-driven product environment (A/B tests, feature flags).

Daily tasks:
• Frame and develop end-to-end payment features (backend & frontend: Node.js, TypeScript, React)
• Integrate and test PSP APIs, ensure payment flow reliability
• Secure sensitive data (Skyflow), debug and document the platform
• Onboard and manage an external dev agency (PSP integration + QA): scoping, code review, validation
• Collaborate daily with the merchant, CTO, PO, QA, and a data scientist
• Manage my deliveries in Agile (daily, Notion, feature flags)

Key achievements:
• Increased authorization rate by 5% and reduced VAMP ratio by 3 (Visa disputes) by optimizing routing and payment rules
• Accelerated delivery pace ~7x (from 1 feature every 2-3 weeks to 1 every 2-3 days) by industrializing an AI-assisted dev workflow (Cursor, Claude Code)
• Integrated 6 PSPs (4 in production), with MID routing and failover
• Delivered 4 3DS/SCA + Apple Pay flows adapted to each PSP's specifics
• Automated payment reporting (Slack × Snowflake × Claude): daily tracking of revenue, refunds, and success rate
• Published and maintained a React payment form library (@sgw-payment/react-pay-form)

Stack: Node.js · TypeScript · AWS Lambda · Amplify Gen2 · DynamoDB · SQS · React · REST/Webhooks · Postman · Jest · Sentry · GitLab CI/CD · Snowflake · Skyflow · 3DS/SCA · PSD2 · PCI DSS · Tokenization · AI (Cursor, Claude Code)
Node.js TypeScript DynamoDB AWS Lambda PSP
Pylote
Fullstack Developer Node.js, NestJS, TypeScript, and AWS
HUMAN RESOURCES
December 2023 - May 2025 (1 year and 5 months)
Paris, France
Fullstack developer and associate of Pylote, a freelancing platform (Chrome extension for freelancers + SaaS for recruiters). Owner of the Chrome extension (20,000+ users) and contributor to the recruiter SaaS (10–50 clients). Still an associate of the company to this day.

Beyond code, I contributed to product and business decisions with the CTO and CEO, particularly regarding the evolution of the business model.

Daily tasks:
• Develop the Chrome extension (freelancer dashboard) and the recruiter SaaS (NestJS, Next.js, React, Auth0)
• Evolve two APIs (freelancer and recruiter client sides): extend NestJS routes, restructure, document
• Develop serverless backend (AWS Lambda, DynamoDB): client/Stripe entry points and jobs (CV generation, tracking…)
• Implement and grow the front & back testing strategy, starting from scratch
• Document the API and internal wikis

Key achievements:
• Led the V1→V2 redesign of the Chrome extension → ~25% reduction in bug/support tickets
• Structured a repository of 7,000+ technical skills (categorization, skill re-synchronization)
• Implemented geographic localization: 4 countries, 25+ regions, 100+ provinces, 5,000+ municipalities
• Delivered automatic LinkedIn info extraction and on-the-fly CV generation
• Introduced the testing strategy (from scratch to critical front & back path coverage)
• Contributed to diversifying the business model by launching a 2nd revenue stream (sponsorship)

Stack: JavaScript · TypeScript · React · Redux · Next.js · Express · NestJS · REST API · Auth0 · AWS Lambda · API Gateway · DynamoDB · Airtable · Stripe · Segment · GitLab · Figma
Node.js NestJS Chrome Extension AWS Lambda DynamoDB
Les Scores de Chantal
Backend Developer Node.js and TypeScript
BANKING AND INSURANCE
October 2023 - November 2023
Improvement of an in-house framework in TypeScript (Advanced TypeScript usage) for data extraction and processing, and creation of a CLI to speed up the development of certain features of this framework.
- CLI Development: Node.js, Inquirer.js, TypeScript,
- In-house framework: Advanced TypeScript, REST API
- Tools: GIT, Github, Notion, Vitest, Yarn, Github Copilot
TypeScript Backend Web Development REST API Software Engineering Node.js

Check out Nicolas's experience

Ronan

Pylote

Reviewed on 1/19/2024

Excellent developer, Nicolas was able to intervene where we needed him and took on the project with brilliance. I recommend him and will use his services again without hesitation.