Aleksi Heinonen

Technical founder & full‑stack engineer · MBA

I design and ship production systems end to end.

I build with AI agents, and help teams do the same. Voice AI, Rust infrastructure and IoT platforms, with a method that keeps the code at the bar of a demanding engineering team. Every claim on this site is measured.

Available for contracts from October 2026 · remote or Tallinn / Helsinki

Start a project → See the work

Portrait of Aleksi Heinonen
Tallinn, Estonia
2M+
lines of code shipped since 2024, tests included
6 days
from first commit to real phone calls on a voice AI agent
60,000+
transactions per second on my own sharded Rust blockchain, 4 shards on AWS
6
bugs found in the Mastra agent framework, all fixed upstream within two days

Selected work

Systems I have designed, built and run

  1. 01 A sharded proof-of-stake blockchain in Rust A DAG-based layer-1 designed for agent-to-agent payments: consensus, execution, sharding, proving, SDKs, wallet and explorer, built from scratch. Distributed systems · Rust 2026 60,885 TPS committed on 4 shards × 4 validators on AWS, scaling linearly at 15,000 TPS per shard
  2. 02 Finnish-language AI phone agent for electricity utilities An AI agent that answers fault-report calls in Finnish, turns them into structured fault reports and connects to the utility's on-premise outage system. Voice AI · B2B SaaS 2026 300k lines of TypeScript across backend and frontend
  3. 03 Autonomous AI marketing crew with its own video studio A team of AI agents led by an AI director that plans, writes, produces long-form video and publishes across social media. Compliance checks run on everything, and a human steps in only where it matters. Multi-agent AI · Content automation 2026 10 specialised agent roles, coordinated by an AI director
  4. 04 IoT energy and machine-health platform, from circuit board to cloud Sensor hardware, firmware, gateways, automated control and a machine-learning analytics platform that learns how rooms and machines behave, cuts energy use and predicts maintenance needs. Embedded · IoT · Machine learning · End to end 2021–2026 6 analytics layers, from raw telemetry to maintenance recommendations
  5. 05 Evidence-based health platform with an AI assistant A consumer health platform with cited long-form articles, condition guides and an AI chat grounded in the platform's own reviewed content. Full-stack · AI · Content 2026 268k lines of application code (backend and frontend)

Expertise

What I can build for you

01

AI agents and automation

Voice agents, multi-agent crews and content pipelines wired into real business systems, with guardrails, approvals and audit trails.

02

Product builds, end to end

From architecture to a running SaaS: backend, frontend, billing, infrastructure as code, CI/CD and monitoring.

03

IoT, control and machine learning

Sensor hardware, firmware and gateways through to control algorithms and ML analytics that predict maintenance.

04

Rust and distributed systems

High-throughput services, consensus and cryptography, with property tests, fuzzing and formal specifications.

How I work

Fast, without cutting corners

  1. Research What you and your end users actually need, then the existing code, before anything is designed.
  2. Plan A written plan and acceptance criteria before any code.
  3. Build Small increments with tests, reviewed and gated: only green ships.
  4. Measure Performance, cost and errors tracked, not guessed.
  5. Hand over Documentation and infrastructure as code, so your team owns the result.

Contact

Have a system to build?

A build, a proof of concept, or your team’s move to agentic development. Tell me what you need and by when.

hello@aleksiheinonen.com

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