FJ
Firas Jday
Tech Lead & Senior Software Engineer
Available for CDI & senior freelance — French & international market
Enterprise platforms and intelligent automations — from architecture to production.
I architect and deliver enterprise backends (NestJS, Supabase), full-stack products (Next.js 15), and intelligent automation workflows (n8n, AI agents) — production-ready, documented, and maintainable.
Calling card
Firas Jday
Tech Lead & Senior Software Engineer · Tunis, Tunisia · 5+ yrs
jdfyras@gmail.com · +21629449117
3d → 3min
multi-agent SQL targeting
// Dossier — Subject 01
Positioning
A senior engineer who owns the whole arc — architecture, build, hardening, and the docs that keep it alive.
File: Firas Jday — Profile
Senior Software Engineer & Tech Lead with 5+ years delivering production systems in TypeScript, Node.js, and Python.
I'm a Senior Software Engineer and Tech Lead with 5+ years delivering production systems in TypeScript, Node.js, and Python — from enterprise transport platforms (NestJS, Supabase, Redis) to intelligent automation workflows (n8n, LangChain, OpenAI). Currently leading architecture and engineering at Aileane on the Parnass fleet-operations platform. I've also shipped automation systems for French-market clients on Upwork and built multi-cloud data pipelines at Mercio. Fluent in French and English. Available for CDI and senior freelance engagements.
- Architecting production backends — NestJS, Supabase/PostgreSQL, Redis, REST & GraphQL APIs
- Building real-time systems — live GPS tracking, SSE, WebSockets, event-driven architectures
- Designing enterprise frontends with Next.js 15, React 19, TanStack Query, and Tailwind CSS
- Delivering intelligent automation workflows (n8n, Zapier, Make) and AI agents (LangChain, OpenAI)
- Engineering cloud data pipelines — GCP, BigQuery, Dataform, Cloud Functions
“I listen to the problem first, then propose the architecture.”
// Index cards — Engagements
How I work with you
Scoped engagements, from a fast audit to a hardened production system.
Automation Audit & Roadmap
Pinpoint exactly where your team is bleeding hours — and leave with a concrete, prioritised plan to reclaim them.
n8nGoogle WorkspaceAPIsData modeling
n8n Workflow Build & Hardening
Workflows that run every night without waking anyone up — error handling, dead-letter queues, and alerting built in from day one.
n8nWebhooksPostgreSQLDocker
Google Workspace Automation Systems
Transform your Google Sheets from a fragile, manually-maintained file into a reliable, self-updating operational system.
Google Apps ScriptGoogle Sheets APIJavaScriptAPIs
AI Agents for Business Workflows
Move beyond the chat demo — build AI that takes real actions: queries your database, calls your APIs, routes decisions, and follows your business rules.
LangChainOpenAI APIPythonVector search
Freelance — Upwork
Selected Work
n8n Automation Engineer & AI Agent Architect
Multi-agent automation workflows and AI-driven business operations for French-market clients.
Dec 2025 — Present
Highlights
- Architected a multi-agent SQL audience-selection system (GPT-4o + Gemini) — 3 days of analyst work down to under 3 minutes
- Integrated LLM decision-making into n8n workflow steps with SQL proxy validation and Teams Adaptive Card approval gates
- Eliminated all manual handoffs across campaign planning, audience selection, and content generation pipelines
Stack
n8n
LangChain
OpenAI API
Python
Apps Script Algorithm Specialist
High-performance inventory consolidation across 100k+ SKUs and four external data sources.
May 2025 — Present
Highlights
- Engineered a 64-column calculation engine processing 100k+ SKUs from 4 external sources — completing in under 90 seconds
- Hardened spreadsheet workflows with parameter validation, file-modification tracking, and full audit logging via a LOGS sheet
- Integrated live REST API feeds so data refreshes with a single menu click, replacing slow manual CSV exports
Stack
Google Apps Script
Google Sheets API
JavaScript
B2B eCommerce Software Engineer
Custom B2B commerce systems with vendor inventory handling and multi-channel automation.
Jan 2025 — Present
Highlights
- Delivered vendor-specific stock management with multi-warehouse sync and automated reorder triggers across custom store and eBay
- Automated the full order lifecycle — from eBay listing sync to shipping label generation — eliminating 4+ hours of daily manual ops
- Built a CRM module tracking vendor relationships, order status, and automated notification sequences from quote through to delivery
Stack
React
Node.js
APIs
Automation
Senior React / Next.js Developer
Production-grade UI development and frontend architecture for React/Next.js applications.
Sep 2024 — Present
Highlights
- Built production React/Next.js interfaces with shadcn/ui, Tailwind CSS, and Framer Motion — pixel-perfect across mobile, tablet, and desktop
- Established reusable component patterns and design-system conventions that cut per-feature UI development time by 40%
- Maintained rapid iteration velocity through tight stakeholder feedback loops — concept to deployed PR in hours, not days
Stack
React
Next.js
Tailwind CSS
// Photo wall — Selected work
Selected projects
Six shipped systems. Tap a photo for the case study.
Enterprise SaaS / Real-timePlive fleet ops
Parnass — Fleet Operations
Transport planning, live GPS fleet ops, EU (RSE) compliance rule engine.
NestJS 11Next.js 15SupabaseRedisMapLibre
Blockchain & NFTB$50K+ · −40% gas
Banana NFT — Backend
Gas-optimised NFT backend, Merkle-tree proofs, per-user minting. 95% test coverage.
Node.jsSolidityEthers.jsHardhat
Full Stack & CloudI80% faster deploys
Intermarché — Data Processing
Azure→GCP multi-cloud ETL, Dataform/BigQuery, CI/CD across 3 envs. TB-scale daily.
PythonGCPDataformBigQueryCircleCI
Backend & DistributedT99.9% uptime
Travelbeds — Microservices
4 specialised APIs, hybrid MongoDB/MSSQL, Redis caching for B2B travel.
Node.jsExpressMongoDBMSSQLRedis
Automation & ProductivityG100k+ SKUs <90s
Gestion des Stock — Add-on
64-metric engine over 100k+ SKUs from 4 sources; single-click sub-90s refresh.
Apps ScriptSheets APIclasp
Blockchain & DeFiXreward calc
XStake — DeFi Staking
Staking dashboard with complex data viz, precise reward calculations, optimised builds.
ReactWeb3
// Stapled CV sheet — Service record
Experience
Firas Jday
CURRICULUM VITÆ · TECH LEAD & SENIOR SOFTWARE ENGINEER
Tech Lead & Senior Software Engineer — Aileane
Feb 2026 - Present
- Architected and delivered a domain-driven NestJS 11 REST API modelling the full transport domain — contracts, service templates, individual courses, and multi-stop driver shifts — on Supabase/PostgreSQL, with a dedicated GPS worker communicating over Redis Pub/Sub
- Designed a DB-driven rule engine enforcing EU driving-time (RSE) compliance and contractual constraints, with a three-level exception system (N1/N2/N3) — business rules configurable by operators without touching code
- Delivered live fleet operations including real-time GPS tracking, SSE streams, and Supabase Realtime push — with an architectural firewall between the published plan and day-of operations, preventing live changes from corrupting the schedule
- Integrated four external systems (Michelin Connected Fleet GPS/tachograph, PTV routing/ETA, Factorial HR, MyRentACar) via scheduled cache tables, keeping the platform fast and available even when third-party APIs are slow or down — with a documented GDPR geolocation register
NestJS · TypeScript · Next.js · Supabase (PostgreSQL) · Redis · TanStack Query · Zustand · MapLibre GL · Microsoft Entra ID · Railway
Senior Automation Consultant (n8n & AI Agents) — Freelance (Upwork)
Dec 2025 - Present
- Engineered multi-step AI agents with LangChain and GPT-4o that autonomously handle document parsing, data enrichment, and decision routing — eliminating analyst bottlenecks in client operations
- Architected end-to-end n8n orchestrations connecting CRM, email, Slack, and databases — delivering fully autonomous pipelines with error alerting and human-approval checkpoints
- Cut manual data-processing time by 90% through intelligent field extraction, format normalisation, and auto-routing — previously a 3+ hour daily task for the client team
- Deployed RAG pipelines enabling clients to query years of internal documentation and support history in natural language, with source citations and configurable confidence thresholds
n8n · Python · LangChain · OpenAI API · PostgreSQL · Docker
Apps Script Algorithm Specialist — Freelance (Upwork)
May 2025 - Present
- Engineered a 64-column inventory calculation engine processing 100k+ SKUs across four external data sources — consolidating in under 90 seconds what previously took hours of manual work
- Cut Apps Script execution time by 80% through batch API calls, PropertiesService caching, and lazy-evaluation strategies that prevent hitting Google's execution timeout limits
- Built parameterised Google Workspace Add-ons with ABC classification, dead-stock identification, and automatic sheet templating — replacing a multi-hour weekly consolidation process
- Integrated Google Sheets with live external REST APIs for real-time inventory synchronisation, with file-modification-date tracking and multi-layer validation safeguards
Google Apps Script · JavaScript · Google Sheets API · Data Structures · Algorithms
B2B eCommerce Software Engineer — Freelance (Upwork)
Jan 2025 - Present
- Delivered a custom B2B storefront with vendor-specific catalogues, multi-warehouse stock management, and automated reorder triggers when stock drops below configurable thresholds
- Built real-time inventory synchronisation across the custom store and eBay marketplace — with conflict-resolution logic to prevent overselling during concurrent orders
- Engineered a CRM module tracking vendor relationships, order lifecycle, and automated communication sequences from quote to delivery confirmation
- Automated the entire order fulfilment pipeline — from payment confirmation to shipping label generation — eliminating 4+ hours of daily manual operations
React · Node.js · eBay API · Inventory Management · Automation
Senior Software Engineer — Mercio
Jun 2023 - Present
- Architected a Java 17/Spring Boot microservices ecosystem powering real-time competitive pricing — domain-driven design with clear service boundaries, async event processing, and full observability
- Engineered a configurable pricing rules engine capable of evaluating complex, multi-variable business conditions at scale without code deployments — rules defined by business teams in the UI
- Deployed and operated containerised services on GKE using Helm charts and GitOps pipelines — zero-downtime rolling releases with automated rollback on failed health checks
- Built Azure-to-GCP data synchronisation pipelines via Cloud Functions and Dataform/BigQuery, cutting pricing analytics latency from 24+ hours down to same-day
Java 17 · Spring Boot · React · GCP · Kubernetes · BigQuery
Senior JavaScript Developer & AI Expert — Cybelle Data
Nov 2024 - Jun 2025
- Designed the multi-agent SQL audience-selection system (GPT-4o, Gemini, Perplexity) orchestrated in n8n — converting natural-language marketing briefs into dynamic SQL audience segments and compressing 3 days of analyst work to under 3 minutes
- Delivered full-stack dashboards and internal tools in React/Next.js, replacing manual spreadsheet reporting with live, self-serve analytics for ops and data teams
- Built French-language AI assistants with LangChain and OpenAI, enabling teams to query operational databases and internal documentation without writing SQL
- Led legacy VBA-to-Node.js migrations, replacing brittle macro workflows with version-controlled, testable service modules deployable through CI/CD pipelines
React.js · n8n · Google Apps Script · Node.js · OpenAI API · LangChain
Senior JavaScript Developer — Tantilab AI
Jul 2023 - Jan 2025
- Automated cross-team business workflows in Google Apps Script — consolidating data from 10+ sources, enforcing validation rules, and eliminating 35% of repetitive daily operations
- Deployed production Node.js/PostgreSQL services on Google App Engine with Secret Manager, automated provisioning scripts, and zero-downtime health-check-based deploys
- Built a self-updating BigQuery documentation system that introspects schema metadata and generates structured technical specs — replacing a full sprint cycle of manual documentation work
- Reduced manual data-processing errors by 90% through intelligent validation layers, automated reconciliation pipelines, and real-time exception alerting to the responsible teams
Google Apps Script · Node.js · PostgreSQL · Google App Engine · BigQuery
Software Engineer — Traveltodo
Nov 2021 - Jan 2022
- Integrated Amadeus GDS via SOAP/XML APIs for real-time availability search across 200+ carriers, with an intelligent caching layer that cut external API calls by 30% on popular routes
- Built a server-side rendered multi-step booking UI with live availability filtering, dynamic pricing display, and a conversion-optimised checkout flow
- Implemented a PCI-compliant payment gateway with 3DS authentication, automated booking-confirmation emails, and PDF e-ticket generation via Puppeteer
React · Node.js · Amadeus API · Payment Gateway
// Folder dividers — Toolkit
Skills
Grouped by file divider — pick a tab.
Node.jsTypescriptNestJSExpress.jsServerless FunctionsREST APIsGraphQLPythonFastAPI
React 19Next.js 15AngularReact Nativeshadcn/uiRadix UITanStack QueryTypeScriptTailwind CSSMaterial-UI
Google Cloud PlatformAWSAzureBigQueryGKECloud FunctionsCloud StorageFirebaseVercelNeon
n8nZapierMake (Integromat)Google Apps ScriptWorkflow AutomationAPI IntegrationTask SchedulingETL Pipelines
DockerKubernetesHelm ChartsJenkinsCircleCICI/CDGradleTerraform
PostgreSQLMongoDBBigQuerySQL ServerRedisFirestoreDrizzle ORMMSSQL
KeycloakOAuth2JWTOpenID ConnectRole-based Access Control
LangChainOpenAI APIsTensorFlowVector Search (RAG)AI Agent OrchestrationWeb3.jsSoliditySmart Contracts
// Sticky notes — Proof in numbers
The numbers
3d → 3min
multi-agent SQL audience targeting
100k+ SKUs <90s
Apps Script inventory engine
90%
less manual data processing
99.9%
uptime on distributed microservices
$50K+
on-chain volume · −40% gas
80%
faster multi-cloud deployments
// Note cards — In their words
What clients say
From Upwork reviews and LinkedIn recommendations.
★★★★★
“Firas is an absolute pro. Working with him is a breeze as he understands your request and does his best to resolve any issues. We will definitely be using him again!”
Upwork clientn8n Automation & AI Agent
★★★★★
“Excellent skills, he fixed my n8n workflow in no time!”
Upwork clientWorkflow Automation
★★★★★
“Proficiency is absolutely superb! Highly recommended. Absolute superb freelancer. He fixed our problem quickly and efficiently.”
Upwork clientNode.js & AI Builder
★★★★★
“Firas is a reliable Freelancer, very skilled as node.js developer. We will brainstormed the development strategy then he worked in autonomy and efficiency. I'll recommend him and look forward to working with him again.”
Upwork clientSenior Node.js Developer
“Firas is a dedicated and passionate developer who becomes unstoppable once he's on a project. As a Senior Full Stack & Cloud Data Engineer specializing in Java, Spring Boot, and modern web technologies, he consistentl…”
Jérémy RochotData Centric Engineer
“Firas is one of the most talented full stack developers I've had the pleasure of working alongside. His technical skills span from Java Spring Boot microservices to React frontends, and he consistently delivered high-…”
Ahmed DalhoumBlockchain Engineer @ Warden Labs | Top Rated Plus Developer
// Stamped seals — Credentials
Certifications
Software Engineer Certificate
HackerRank · Sep 2025
Node.js (Intermediate) Certificate
HackerRank · Jan 2024
BSc Computer Science
ISET Nabeul · 2022
Frequently Asked Questions
I architect and build enterprise-grade platforms end-to-end — from NestJS backends and Next.js frontends to data pipelines and real-time fleet-management systems. My current work at Aileane (Parnass) covers domain modelling, rule engines, GPS tracking, and multi-process backend architecture for France's regulated passenger-transport sector.
I build production n8n multi-agent pipelines that orchestrate GPT-4o, Gemini, and Perplexity to automate complex workflows — like compressing 3 days of marketing segmentation work to under 3 minutes. I also build Google Apps Script engines, LangChain agents, and natural-language-to-SQL systems that put database power in non-technical hands.
Yes — my current role at Aileane is Tech Lead & Senior Software Engineer, and I'm available for CDI positions or senior freelance engagements. I'm comfortable owning architecture decisions, API contracts, delivery cadence, and cross-team integrations from day one.
Extensively. I've built Apps Script add-ons, Drive/Sheets/Gmail integrations, and GCP data pipelines (Cloud Functions, BigQuery, Dataform, GKE) for enterprise clients — including a TB-scale Azure-to-GCP retail data pipeline running at 99.9% availability.
A short discovery call is the fastest path. I listen to the problem first — then propose a concrete architecture or automation roadmap with scope, timeline, and clear deliverables.
Firas Jday
Tech Lead & Senior Software Engineer
Have a real domain problem to solve? Let’s talk architecture — not just technology.
A short discovery call is the fastest path. I listen to the problem first, then propose a concrete architecture or automation roadmap.
— or reach me directly —