Senior Product Engineer

Leonardo Chiaramonti

Mobile-first fullstack. From the RN component to the EKS pod.

I build and modernize production software end-to-end: React Native apps in the field, React 19 web frontends, Java microservices, and the AWS platform underneath — without breaking what is already running.

0+
years in production software
0
retail stores on a platform I ran end-to-end
0
Kubernetes releases owned on EKS

Case studies

Work that shipped

Selected work from enterprise SaaS in food safety and retail compliance (GDO clients such as Conad Nord Ovest and Carrefour). Code is proprietary — these are the problems, the approach, and what changed.

REC-01 / Legacy modernization · product ownership

Rewriting a live backoffice without stopping the business

The web backoffice for a major Italian retail cooperative (Conad Nord Ovest) ran on Create React App, React 16, MUI v4 and untyped JavaScript — hard to change, harder to hire for. For a year I ran this product alone — engineering and product decisions — serving 650 stores and ~€300k/yr of revenue on its own.

Problem

The product needed new features weekly. A big-bang rewrite would freeze delivery for months; staying on the legacy stack made every feature slower and riskier.

Impact

  • A typed, testable codebase the team can actually hire for.
  • New listing screens go from days to hours thanks to the generic DataTable and route conventions.
  • Zero production downtime during the migration.
  • Owned product and delivery solo for a year: roadmap, priorities and releases for 650 stores — a product worth ~€300k/yr on its own.

Approach

  • Rebuilt the application on TanStack Start, React 19, TanStack Router/Query/Table/Form, Zod, shadcn/ui and Tailwind v4 — file-based routing, Suspense loader queries, search params as the single source of truth for pagination, sorting and filters.
  • Designed a generic server-side DataTable and a brand-consistent design system so new CRUD screens are configuration, not code.
  • Kept the legacy app in production during the transition; the same Spring Boot backend serves both, so cutover is per-screen, not per-product.
TanStack StartReact 19TypeScript strictZodshadcn/uiTailwind v4Vite
REC-02 / Mobile at scale

A field app HACCP inspectors rely on every day

BS-SAFE is the field app used by food-safety inspectors on site: checklists, attachments, signatures, calendars — often on flaky connections.

Problem

One codebase had to ship reliably to iOS and Android across dev, staging and production, with fast fixes in the field and no broken releases.

Impact

  • Inspectors get fixes in hours via OTA instead of days via store review.
  • Every release is exercised by E2E flows before it reaches a device.
  • One team ships three environments and two stores from a single codebase.

Approach

  • Expo SDK 53 + React 19 + React Native 0.79 with expo-router, NativeWind, MMKV, Reanimated and react-hook-form + Zod for offline-tolerant forms.
  • Multi-environment EAS builds (dev / staging / prod) with over-the-air updates for instant hotfixes that skip the store review cycle.
  • Quality gates in CI: 12 GitHub Actions workflows covering lint, type-check, unit tests and Maestro end-to-end flows; Sentry in production.
  • Performance work where it hurts: GridList over FlatList, calendar refactor, BottomSheet flows, keyboard handling.
Expo SDK 53React Native 0.79EAS Build + UpdatesMaestro E2ESentryGitHub Actions
REC-03 / IoT end-to-end

Cold-chain monitoring: from probe supplier to production pod

Food-safety compliance requires continuous temperature monitoring of fridges and cold rooms in every store. I conceived the company’s IoT solution and owned the whole chain — including choosing the physical probe and its supplier, and installing the hardware on site.

Problem

Manual temperature logging is error-prone, does not satisfy auditors, and off-the-shelf IoT platforms were expensive, inflexible and impossible to integrate with the HACCP suite.

Impact

  • Continuous, automated cold-chain monitoring instead of manual logs.
  • Auditor-ready temperature records with alerting on threshold violations.
  • One person covered the entire chain: hardware sourcing → backend → Kubernetes release → field installation.

Approach

  • Scouted and selected the temperature probe and the hardware supplier: evaluation of cost, reliability and fit with the compliance requirements.
  • Designed the device management flow in the Java backend: device registration, auto-assignment to the responsible department, client-side grants, mock mode for development.
  • Compliance logic on top of the readings: thresholds, alerts and non-conformity records that feed the existing HACCP flows.
  • Shipped as the iot-compliance release on EKS, observable via OpenTelemetry like every other service.
  • Installed and commissioned the probes physically on site in the stores.
IoT temperature probesJava / Spring BootPostgreSQLEKS (iot-compliance)OpenTelemetry + SigNoz
REC-04 / Platform ownership

The AWS platform every product deploys on

A multi-product SaaS (mobile apps, web backoffices, Java microservices, microfrontends) needed real infrastructure: isolated environments, repeatable deploys, observability.

Problem

Deploys were manual and environment drift was constant. Nobody could answer "what exactly is running in prod, and how did it get there?"

Impact

  • Owner of ~12 production Kubernetes releases across the cluster.
  • A new microservice goes from repo to prod-ready deploy in a day, not a sprint.
  • Incidents start from traces and dashboards, not from guesswork.

Approach

  • Terraform multi-account AWS organization: management / audit / dev / staging / prod accounts, centralized CloudTrail, IAM SSO, reusable modules for VPC, RDS, Redis, ECR and EKS.
  • A single reusable eks-release-template Terraform module so every service (auth, payments, copilot, IoT compliance, frontends...) deploys the same way, with External Secrets and the AWS Load Balancer Controller.
  • Typed CI/CD pipelines per artifact class (Java, SPA, microfrontend, Python, DB migration) plus ArgoCD for cluster state.
  • Observability as a default: OpenTelemetry auto-instrumentation on every Java service, traces and dashboards in SigNoz.
TerraformAWS (EKS, RDS, S3, IAM/IRSA)ArgoCDHelmOpenTelemetrySigNoz
REC-05 / AI in production

LLMs doing real work, not demos

Two AI systems shipped for enterprise users: a product copilot embedded in the SaaS suite, and a document digitizer for arbitrary PDFs.

Problem

Enterprise AI fails on the boring parts: malformed PDFs, hallucinated fields, cost control, and integration with existing auth and data.

Impact

  • Documents that previously required manual data entry become structured records automatically.
  • The copilot answers inside the product with tenant-aware context, not in a separate chat tab.
  • Development iterates without burning API budget thanks to mock mode.

Approach

  • Copilot: Spring Boot 3 / Java 17 microservice with Spring AI, plus a Next.js 15 + assistant-ui frontend, integrated with the platform’s OAuth identity provider.
  • Digitizer: NestJS + BullMQ pipeline that extracts structured JSON from PDFs with Claude, falling back to multimodal vision when the text layer is unusable; retry/backoff and a zero-cost mock mode for development.
  • Structured outputs validated against schemas — the model proposes, the code disposes.
Spring AIJava 17Next.js 15NestJS + BullMQAnthropic Claude (text + vision)PostgreSQL + Prisma

Personal projects

What I build off the clock

Side projects built with production discipline: typed code, tests, CI, and written specs — not weekend hacks.

Ouroboros

Incremental rebirth RPG for mobile

A mobile incremental RPG with active runs and passive soul progression across rebirths, built on a pure-function game engine with offline tick simulation and big-number math.

  • Custom deterministic game engine (simulate) with a modifier system and dual Zustand stores
  • 33 test files covering combat, rebirth, loot and zone logic
  • 24 engineering docs: architecture, formulas, MVP scope
React Native 0.81Expo SDK 54TypeScriptZustand + MMKVReanimated 4Jest + Maestro
Repo available on request

Recovery Companion

Trauma-informed addiction recovery app

A clean-days tracker with an SOS crisis flow (guided breathing, SMS to trusted contacts), built spec-first with a written product constitution: trauma-informed, evidence-led, privacy by design.

  • Offline-first SOS flow with accessibility and VoiceOver tests (WCAG AA)
  • Encrypted MMKV vault for PII, Drizzle + SQLite for structured data
  • Spec-driven workflow with 23+ test files and CI
Expo SDK 53TypeScriptDrizzle ORM + SQLiteReact QueryZodLottie
Repo available on request

Babayaga

AI tarot reading app for mobile

A tarot reading app with an animated cross-spread layout: ask a question, reveal the cards one by one, and read the seer’s interpretation delivered with a typewriter effect.

  • Animated cross-spread card layout and reveal flow built with Reanimated
  • Monetization scaffolding: RevenueCat subscriptions and AdMob interstitials
  • 79 illustrated card assets, EAS builds and GitHub Actions CI
Expo SDK 53React Native 0.79TypeScriptReact Query + ZustandReanimatedNativeWind
Repo available on request

Skills

Four technical axes — plus the one that ships them

Most fullstack engineers cover two of these. I work across all four daily — and I can run the delivery process around them when the team needs it.

01

Mobile

The strongest axis: production React Native since 2018.

  • React Native + Expo (SDK 51→54)
  • expo-router, React Navigation
  • EAS Build / Submit / Updates (OTA)
  • MMKV, SQLite, secure storage
  • Reanimated, gesture-driven UI
  • jest-expo, Testing Library, Maestro E2E
  • Sentry, i18next, push notifications
02

Frontend Web

Two generations: maintain React 16 legacy, build React 19 modern.

  • React 19, TypeScript strict
  • TanStack Router / Query / Table / Form / Start
  • Next.js 15, Module Federation (Nx 22)
  • Tailwind v4, shadcn/ui, Radix, MUI
  • Zod, react-hook-form, Zustand, SWR
  • Vitest, Playwright, Jest + RTL
  • Design systems, theming, accessibility
03

Backend Java / Node

From a 150-service Spring monolith to Java 17 microservices.

  • Spring Boot 2.3 → 3.5, Java 8 → 17
  • JPA/Hibernate, Flyway, ShedLock
  • OAuth2 / JWT, Spring Security
  • HikariCP read/write splitting, graceful shutdown
  • PDF generation pipelines (PDFBox, Thymeleaf)
  • NestJS, BullMQ, Prisma, Redis
  • Testcontainers integration testing
04

Platform / DevOps

The axis most fullstack engineers do not have.

  • Terraform multi-account AWS Organizations
  • EKS, Helm, ArgoCD, External Secrets
  • IAM IRSA — zero static credentials
  • Docker multi-stage, container-aware JVM tuning
  • OpenTelemetry, SigNoz, custom dashboards
  • CodePipeline, Bitbucket Pipelines, GitHub Actions
  • CloudFront, S3, RDS, ElastiCache
05

Product & Delivery

Not a certification collector: roles I held because the product needed them.

  • Product Owner (company-wide stint) — coordinated a 10+ person team: assigned work, set priorities, kept shipping code on shared projects
  • Hardware sourcing — scouted the temperature probe and supplier for the company IoT solution, then installed it on site
  • Ran BS-Conad completely solo for a year — product + engineering, 650 stores, ~€300k/yr revenue
  • Scrum Master (current) — facilitation without slowing engineers down
  • Stakeholder management with enterprise retail clients (GDO)
  • Discovery → spec → delivery: written specs, ADRs, engineering docs
  • Backlog triage informed by production data (traces, Sentry, support)

Services

How I can help

Available for senior/lead roles and selected freelance engagements.

Legacy modernization

Incremental rewrites of aging React/JS frontends to typed, modern stacks — while the product keeps shipping. Strategy, architecture, and hands-on code.

Mobile end-to-end

React Native / Expo apps from zero to both stores: architecture, offline-tolerant UX, EAS pipelines, OTA updates, E2E testing, and store submission.

Cloud platform on AWS

Terraform-first AWS setups: multi-account organizations, EKS clusters, CI/CD pipelines, and observability that tells you what broke before your users do.

AI features that ship

LLM integration with production discipline: structured outputs, schema validation, cost control, fallbacks, and evaluation — copilots, document extraction, RAG.

Contact

Let’s talk

Remote-first, based in Italy. Open to senior fullstack, mobile lead, and platform roles — or a concrete problem you want solved.