# Metacode Oy — Rock-Solid Software Architecture & Backend Engineering

> Built to last. 25 years in production across fintech, high-scale SaaS, and regulated platforms. Finnish craftsmanship, zero architectural fluff.

- **Entity**: Metacode Oy (Helsinki, Finland — Business ID: 3375232-1 • VAT: FI33752321)
- **Founder**: Jouni Tuovinen — Founder & Lead Software Architect
- **Contact Email**: jouni@metacode.fi
- **Phone**: +358 50 307 8306
- **LinkedIn**: https://www.linkedin.com/in/jounituovinen/
- **Sovereign Infrastructure**: UpCloud Sovereign European Cloud (Helsinki, Finland)

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## 1. What We Do (#services)

### 01 / FOUNDATION: Software & Solution Architecture
Designing scalable distributed systems from scratch, modernizing monolithic legacy systems, domain boundaries, and zero technical debt.
- Distributed systems design & high-availability topology
- Legacy monolith deconstruction into resilient microservices or modular monoliths
- Domain-Driven Design (DDD) with clean bounded contexts
- Defensive architecture preventing technical debt accumulation
- Zero-latency distributed state & caching strategies
- *Metrics: 99.99% Availability | Zero Tech Debt | Decoupled Domains*

### 02 / EXECUTION: High-Performance Backend & Integrations
Mission-critical APIs (REST, webhooks), relational database optimization (MySQL schema & query profiling), and autonomous AI agent tooling (Model Context Protocol / MCP).
- Sub-millisecond REST & webhook integration pipelines
- Relational database profiling, indexing strategies & deadlock elimination
- Autonomous AI agent toolchains using Model Context Protocol (MCP)
- High-throughput transactional queue systems (Redis, Kafka, AMQP)
- Automated idempotency, rate limiting, and backpressure handling
- *Metrics: Sub-ms Latency | MCP Server Endpoints | MySQL Profiling*

### 03 / GOVERNANCE: Security, Cloud Architecture & European Sovereignty
Application-layer encryption, hardened IAM/SSO models, and resilient cloud architectures across AWS, GCP, and sovereign European infrastructure.
- Enterprise cloud architectures across AWS and Google Cloud Platform (GCP)
- Zero-Knowledge application-layer encryption (XChaCha20-Poly1305)
- Granular multi-tenant Role-Based Access Control (RBAC) & SSO/IAM
- Sovereign European infrastructure deployments (UpCloud, Linux) for strict data residency and NIS2 compliance
- Auditable cryptographic key derivation and secret management
- *Metrics: AWS & GCP | XChaCha20-Poly1305 | Sovereign EU*

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## 2. Selected Work & Case Studies (#cases)

### 1. PromptEasy.eu — Sovereign AI Governance Platform (Proprietary SaaS)
- **Role**: Lead Architect & Founder
- **Architecture**: Zero-Knowledge application-layer encryption (XChaCha20-Poly1305), Model Context Protocol (MCP) server endpoints for autonomous agents, multi-tenant RBAC, automated onboarding.
- **GDPR vs. Audit Integrity**: Cryptographic GDPR erasure engine enabling verifiable hard-deletion of users, sensitive prompts, and entire tenants (Right to be Forgotten) while mathematically preserving immutable cryptographic audit trail integrity and ledger continuity.
- **Stack**: PHP 8.4 / Laravel 12, TypeScript / Next.js, MySQL 8.4, Docker, UpCloud European Cloud.
- **Metrics**: XChaCha20-Poly1305 Encryption | Live MCP Server | 100% EU Data Residency | Verifiable GDPR Hard-Delete
- **Live Platform**: https://prompteasy.eu

### 2. Deterministic AI Recruitment & Talent Screening Platform
- **Role**: Core System Architecture & Technical Advisory
- **Subtitle**: High-Throughput Candidate Evidence & Screening Pipeline
- **Architecture**: High-throughput screening pipeline pairing deterministic business logic with surgical LLM evidence extraction. Zero hallucinations, minimal token consumption, and strictly human-led qualification decisions.
- **Stack**: Modern web architecture, LLM orchestration, relational data modeling, asynchronous queues.

### 3. Regulated Cryptocurrency Exchange & Custody
- **Role**: Senior Backend Engineering & Compliance
- **Architecture**: Hardened transaction APIs, automated AML/KYC workflows, and supervisory reporting under FIN-FSA oversight.
- **Stack**: High-security REST APIs, PHP, MySQL, audit logging pipelines.

### 4. Global Electric Vehicle Charging Infrastructure
- **Role**: Senior Backend & API Architecture
- **Architecture**: Core mobile API interfaces and event-driven backend services powering a distributed international IoT charging network.
- **Stack**: Microservices, high-concurrency API gateways, cloud telemetry.

### 5. Global Aftermarket & Device Lifecycle SaaS
- **Role**: Lead Technical Architect — Enterprise Key Account
- **Architecture**: Led end-to-end technical architecture and hands-on delivery for the platform’s largest global enterprise client, bridging executive stakeholder requirements with high-volume workflow automation, financial reporting, and sub-second performance.
- **Stack**: PHP (High-Performance MVC), JavaScript, MySQL (High-Concurrency Schema), REST APIs, Financial Data Modeling, Linux Containers.
- **Metrics**: #1 Enterprise Account | Multi-Currency Financials | Global Service Scale

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## 3. Engineering Standards (#standards)

- **PHPStan Level 10 Static Typing**: Zero tolerance for type errors or loose typing in backend systems. Every class is mathematically proven correct.
- **95%+ Automated Test Coverage**: PHPUnit and integration test suites as standard delivery policy.
- **Zero-Trust & Zero-Knowledge**: Cryptographic tenant data isolation (XChaCha20-Poly1305) and strict IAM governance.
- **Strict API Contracts & OpenAPI**: Every integration boundary is formally governed by OpenAPI 3.1 specifications with automated runtime validation. Strictly typed request/response envelopes, robust idempotency keys, and backward-compatible versioning guarantee zero silent contract breakage across distributed services.
- **Deterministic Blue-Green Deployments**: Production deployments must never interrupt live customer sessions or drop in-flight transactions. We engineer hardened CI/CD delivery pipelines featuring automated blue-green container rotation, strict health-check gating, and backward-compatible zero-downtime database migrations. Any anomaly triggers immediate, automated traffic rollback.
- **Agent-Ready Architecture**: Semantically structured for autonomous AI crawlers and LLM retrieval (RFC 9329 & MCP).

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## 4. Engagement Models

- **B2B Contract Architecture & Engineering**: Senior Lead / Architect for enterprise deliveries (Metacode Oy).
- **Architecture Reviews & Audits**: Codebase quality, database performance profiling, and security posture checks.
- **Fractional CTO**: Strategic technical steering and system design for growing technology companies.

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## 5. Contact (#contact)

- **Entity**: Metacode Oy (Helsinki, Finland)
- **Representative**: Jouni Tuovinen — Founder & Lead Software Architect
- **Direct Email**: jouni@metacode.fi
- **Phone**: +358 50 307 8306
- **Social**: https://www.linkedin.com/in/jounituovinen/
- **Cloud & Infrastructure Posture**: Metacode operates its own proprietary SaaS platforms and internal workloads exclusively on sovereign European cloud infrastructure (UpCloud Sovereign Cloud, FI-HEL1 and FI-HEL2, 100% EU data residency). For client engagements, we design, deploy, and harden distributed architectures natively across AWS, Google Cloud Platform, and hybrid sovereign European clouds, strictly guided by client security, regulatory, and scalability requirements.